Comparative analysis of physiologic responses to three different maximal graded exercise test protocols in healthy women

Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults: an overview of meta-analyses representing over 20.9 million observations from 199 unique cohort studies

OBJECTIVE

To examine and summarise evidence from meta-analyses of cohort studies that evaluated the predictive associations between baseline cardiorespiratory fitness (CRF) and health outcomes among adults.

DESIGN

Overview of systematic reviews.

DATA SOURCE

Five bibliographic databases were searched from January 2002 to March 2024.

RESULTS

From the 9062 papers identified, we included 26 systematic reviews. We found eight meta-analyses that described five unique mortality outcomes among general populations. CRF had the largest risk reduction for all-cause mortality when comparing high versus low CRF (HR=0.47; 95% CI 0.39 to 0.56). A dose-response relationship for every 1-metabolic equivalent of task (MET) higher level of CRF was associated with a 11%-17% reduction in all-cause mortality (HR=0.89; 95% CI 0.86 to 0.92, and HR=0.83; 95% CI 0.78 to 0.88). For incident outcomes, nine meta-analyses described 12 unique outcomes. CRF was associated with the largest risk reduction in incident heart failure when comparing high versus low CRF (HR=0.31; 95% CI 0.19 to 0.49). A dose-response relationship for every 1-MET higher level of CRF was associated with a 18% reduction in heart failure (HR=0.82; 95% CI 0.79 to 0.84). Among those living with chronic conditions, nine meta-analyses described four unique outcomes in nine patient groups. CRF was associated with the largest risk reduction for cardiovascular mortality among those living with cardiovascular disease when comparing high versus low CRF (HR=0.27; 95% CI 0.16 to 0.48). The certainty of the evidence across all studies ranged from very low-to-moderate according to Grading of Recommendations, Assessment, Development and Evaluations.

CONCLUSION

We found consistent evidence that high CRF is strongly associated with lower risk for a variety of mortality and incident chronic conditions in general and clinical populations.

Measuring Cardiorespiratory Fitness without Exercise Testing: The Development and Validation of a New Tool for Spanish Adults

Background: Cardiorespiratory fitness (CRF) is an important component of overall physical fitness and is associated with numerous health benefits, including a reduced risk of heart disease, diabetes, and obesity. However, direct measurement of CRF is time-consuming and therefore not feasible for screening purposes. Methods: A maximal treadmill exercise test with the Bruce protocol was performed to estimate VO2max in 1047 Spanish men and women aged 17 to 62 years. Weight, height, and heart rate were measured. Leisure-time physical activity (LTPA) was recorded using the Minnesota Leisure Time Physical Activity Questionnaire. A multiple linear regression model was developed to predict exercise-based VO2max. The validity of the model was examined by correlation, concordance, Bland-Altman analysis, cross-validation, and construct validity analysis. Results: There was no significant difference between VO2max obtained by the Bruce protocol (43.56 mL/kg/min) or predicted by the equation (43.59 mL/kg/min), with R2 of 0.57, and a standard error of the estimate of 7.59 mL/kg/min. Pearson's product-moment correlation and Lin's concordance correlation between measured and predicted CRF values were 0.75 and 0.72, respectively. Bland-Altman analysis revealed a significant proportional bias of non-exercise eCRF, overestimating unfit and underestimating highly fit individuals. However, 64.3% of participants were correctly classified into CRF tertile categories, with an important 69.9% in the unfit category. Conclusions: The eCRF equation was associated with several cardiovascular risk factors in the anticipated directions, indicating good construct validity. In conclusion, the non-exercise eCRF showed a reasonable validity to estimate true VO2max, and it may be a useful tool for screening CRF.

Improving Reporting of Exercise Capacity Across Age Ranges Using Novel Workload Reference Equations

Exercise capacity (EC) is an important predictor of survival in the general population and in subjects with cardiopulmonary disease. Despite its relevance, considering the percent-predicted workload (%pWL) given by current equations may overestimate EC in older adults. Therefore, to improve the reporting of EC in clinical practice, our main objective was to develop workload reference equations (pWL) that better reflect the relation between workload and age. Using the Fitness Registry and the Importance of Exercise National Database (FRIEND), we analyzed a reference group of 6,966 apparently healthy participants and 1,060 participants with heart failure who underwent graded treadmill cardiopulmonary exercise testing. For the first group, the mean age was 44 years (18 to 79); 56.5% of participants were males and 15.4% had obesity. Peak oxygen consumption was 11.6 ± 3.0 METs in males and 8.5 ± 2.4 METs in females. After partition analysis, we first developed sex-specific pWL equations to allow comparisons to a healthy weight reference. For males, pWL (METs) = 14.1-0.9×10-3×age2 and 11.5-0.87×10-3×age2 for females. We used those equations as denominators of %pWL, and based on their distribution, we determined thresholds for EC classification, with average EC defined by the range corresponding to 85% to 115%pWL. Compared with %pWL using current equations, the new equations yielded better-calibrated %pWL across different age ranges. We also derived body mass index-adjusted pWL equations that better assessed EC in subjects with heart failure. In conclusion, the novel pWL equations have the potential to impact the report of EC in practice.

The Impact of Body Composition on Cardiorespiratory Fitness in Adult Females

INTRODUCTION

 This study investigates the impact of body composition on cardiorespiratory fitness (CRF) in adult females, focusing on factors such as maximal oxygen uptake (VO2 max). It also emphasizes the importance of maintaining a physically active lifestyle for achieving CRF. Previous research links CRF to protection against metabolic syndrome.

OBJECTIVE

 To investigate the impact of body composition as specified by body mass index (BMI), fat-free mass (FFM), fat mass (FM), and basal metabolic rates (BMRs) on CRF in adult females.

MATERIALS AND METHODS

Adult females aged 19-24 participated in this prospective cross-sectional experimental study (n=110). The study excluded those with specific health conditions. Anthropometric measurements, bio-impedance analysis, and a Balke treadmill test were conducted to assess VO2 max and, hence, the CRF. Nutrient intake was assessed, and energy requirements were calculated. The data were analyzed using Statistical Product and Service Solutions (SPSS, version 21; IBM SPSS Statistics for Windows, Armonk, NY). The test statistics deployed were mean (± SD), ANOVA, Pearson's correlation coefficient, post-hoc Bonferroni test, and regression analysis.

RESULTS

 The study revealed significant differences in anthropometry among BMI categories. Energy intake showed no significant variation. Body mass distribution, BMRs, and vital signs significantly differed among BMI groups. Most participants exhibited poor CRF; a negative correlation between BMI and VO2 max was observed.

CONCLUSION

Body compositions, particularly BMI and FFM, body fat percentage, and BMR, influence CRF in young adult females. Poor CRF was prevalent among participants, indicating a potential impact on cardiovascular health. The findings underline the importance of addressing lifestyle factors in promoting better cardiorespiratory health among young adult females.

Development, validation, and transportability of several machine-learned, non-exercise-based VO2max prediction models for older adults

PURPOSE

There exist few maximal oxygen uptake (VO2max) non-exercise-based prediction equations, fewer using machine learning (ML), and none specifically for older adults. Since direct measurement of VO2max is infeasible in large epidemiologic cohort studies, we sought to develop, validate, compare, and assess the transportability of several ML VO2max prediction algorithms.

METHODS

The Baltimore Longitudinal Study of Aging (BLSA) participants with valid VO2max tests were included (n = 1080). Least absolute shrinkage and selection operator, linear- and tree-boosted extreme gradient boosting, random forest, and support vector machine (SVM) algorithms were trained to predict VO2max values. We developed these algorithms for: (a) for the overall BLSA, (b) by sex, (c) using all BLSA variables, and (d) for variables common in aging cohorts. Finally, we quantified the associations between measured and predicted VO2max and mortality.

RESULTS

The age was 69.0 ± 10.4 years (mean ± SD) and the measured VO2max was 21.6 ± 5.9 mL/kg/min. Least absolute shrinkage and selection operator, linear- and tree-boosted extreme gradient boosting, random forest, and support vector machine yielded root mean squared errors of 3.4 mL/kg/min, 3.6 mL/kg/min, 3.4 mL/kg/min, 3.6 mL/kg/min, and 3.5 mL/kg/min, respectively. Incremental quartiles of measured VO2max showed an inverse gradient in mortality risk. Predicted VO2max variables yielded similar effect estimates but were not robust to adjustment.

CONCLUSION

Measured VO2max is a strong predictor of mortality. Using ML can improve the accuracy of prediction as compared to simpler approaches but estimates of association with mortality remain sensitive to adjustment. Future studies should seek to reproduce these results so that VO2max, an important vital sign, can be more broadly studied as a modifiable target for promoting functional resiliency and healthy aging.

Independent and joint associations of cardiorespiratory fitness and BMI with dementia risk: the Cooper Center Longitudinal Study

OBJECTIVE

This study aimed to examine the association of midlife fitness and body mass index (BMI) with incident dementia later in life.

DESIGN AND PARTICIPANTS

A cohort study of 6428 individuals (mean age 50.9±7.6 years) from the Cooper Center Longitudinal Study.

MEASURES

Cardiorespiratory fitness and BMI were assessed twice (1970-1999) during visits to the Cooper Clinic, a preventive medicine clinic in Dallas, Texas. These measures were examined as continuous and categorical variables. As continuous variables, fitness and BMI were examined at baseline (averaged of two examinations) and as absolute change between exams (mean time 2.1±1.8 years). Variables were categorised: unfit versus fit and normal versus overweight/obese. Medicare claims data were used to obtain all-cause dementia incidence (1999-2009). Mean follow-up between midlife examinations and Medicare surveillance was 15.7 ((SD=6.2) years. Multivariable models were used to assess the associations between fitness, BMI and dementia.

RESULTS

During 40 773 person years of Medicare surveillance, 632 cases of dementia were identified. After controlling for BMI and covariates, each 1-metabolic equivalent increment in fitness was associated with 5% lower (HR 0.95; 95% CI 0.90 to 0.99) dementia risk. In comparison, after controlling for fitness and covariates, each 1 kg/m2 increment in BMI was associated with a 3.0% (HR 1.03; 95% CI 1.00 to 1.07) higher risk for dementia, yet without significance (p=0.051). Similar findings were observed when the exposures were categorised. Changes in fitness and BMI between examinations were not related to dementia. Jointly, participants who were unfit and overweight/obese had the highest (HR 2.28 95% CI 1.57 to 3.32) dementia risk compared with their fit and normal weight counterparts.

CONCLUSION

Lower midlife fitness is a risk marker for dementia irrespective of weight status. Being unfit coupled with overweight/obese status might increase one's risk for dementia even further.

Exercise-Induced Blood Pressure Dynamics: Insights from the General Population and the Athletic Cohort

Blood pressure (BP) dynamics during graded exercise testing provide important insights into cardiovascular health, particularly in athletes. These measurements, taken during intense physical exertion, complement and often enhance our understanding beyond traditional resting BP measurements. Historically, the challenge has been to distinguish 'normal' from 'exaggerated' BP responses in the athletic environment. While basic guidelines have served their purpose, they may not fully account for the complex nature of BP responses in today's athletes, as illuminated by contemporary research. This review critically evaluates existing guidelines in the context of athletic performance and cardiovascular health. Through a rigorous analysis of the current literature, we highlight the multifaceted nature of exercise-induced BP fluctuations in athletes, emphasising the myriad determinants that influence these responses, from specific training regimens to inherent physiological nuances. Our aim is to advocate a tailored, athlete-centred approach to BP assessment during exercise. Such a paradigm shift is intended to set the stage for evidence-based guidelines to improve athletic training, performance and overall cardiovascular well-being.

Converging protective pathways: Exploring the linkage between physical exercise, extracellular vesicles and oxidative stress

Physical Exercise (EXR) has been shown to have numerous beneficial effects on various systems in the human body. It leads to a decrease in the risk of mortality from chronic diseases, such as cardiovascular disease, cancer, metabolic and central nervous system disorders. EXR results in improving cardiovascular fitness, cognitive function, immune activity, endocrine action, and musculoskeletal health. These positive effects make EXR a valuable intervention for promoting overall health and well-being in individuals of all ages. These beneficial effects are partially mediated by the role of the regular EXR in the adaptation to redox homeostasis counteracting the sudden increase of ROS, the hallmark of many chronic diseases. EXR can trigger the release of numerous humoral factors, e.g. protein, microRNA (miRs), and DNA, that can be shuttled as cargo of Extracellular vesicles (EVs). EVs show different cargo modification after oxidative stress stimuli as well as after EXR. In this review, we aim to highlight the main studies on the role of EVs released during EXR and oxidative stress conditions in enhancing the antioxidant enzymes pathway and in the decrease of oxidative stress environment mediated by their cargo.

Association between baseline levels of muscular strength and risk of stroke in later life: The Cooper Center Longitudinal Study

OBJECTIVE

Muscular strength is an important component of physical fitness. We evaluated the relationship between baseline muscular strength and risk of stroke among adults who were aged ≥65 years during follow-up.

METHODS

7627 healthy adults (mean age 43.9 years, 86.0% male) underwent a baseline physical examination between 1980 and 1989. Muscular strength was determined by 1-repetition maximum measures for bench press and leg press and categorized into age and sex-specific tertiles for each measure. Cardiorespiratory fitness (CRF) was assessed via a maximal treadmill exercise test. Those enrolled in fee-for-service Medicare from 1999 to 2019 were included in the analyses. Associations between baseline strength and stroke outcomes were estimated using a modified Cox proportional hazards model. In a secondary analysis, we examined stroke risk by categories of CRF where Quintile 1 = low, Quintiles 2-3 = moderate, and Quintiles 4-5 = high CRF based on age and sex.

RESULTS

After 70,072 person-years of Medicare follow-up, there were 1211 earliest indications of incident stroke. In multivariable analyses, the hazard ratio (HR) (95% confidence interval (95%CI)) for stroke across bench press categories were 1.0 (referent), 0.96 (0.83-1.11), and 0.89 (0.77-1.04), respectively (p trend = 0.14). The trend across categories of leg press was also non-significant (p trend = 0.79). Adjusted HR (95%CI) for stroke across ordered CRF categories were 1.0 (referent), 0.90 (0.71-1.13), and 0.72 (0.57-0.92) (p trend < 0.01).

CONCLUSION

While meeting public health guidelines for muscular strengthening activities is likely to improve muscular strength as well as many health outcomes in older adults, performing such activities may not be helpful in preventing stroke. Conversely, meeting guidelines for aerobic activity is likely to improve CRF and lower stroke risk.

Omega-3 index, cardiorespiratory fitness, and cognitive function in mid-age and older adults

Higher levels of omega-3 fatty acids in red blood cell membranes (omega-3 index or O3I) and cardiorespiratory fitness (CRF) are each associated with reduced cognitive impairment, but little research has examined the relationship between O3I and cognitive function while accounting for CRF. We analyzed cross-sectional data from 5,464 healthy men and women aged 55-85 years who had preventive medical examinations between 2009 and 2023. Primary exposures included O3I (<4.0%, 4.0-7.9%, or ≥ 8.0%) and age- and sex-based CRF quintile (1 = low, 2-3 = moderate, 4-5 = high). Cognitive impairment was defined as a Montreal Cognitive Assessment score of ≤ 25. We used Poisson regression to estimate relative risks (RR) of cognitive impairment, controlling for covariates. O3I < 4% was associated with increased cognitive impairment relative to ≥ 8.0% (RR, 1.21; 95% CI, 1.01-1.44) in a partially adjusted model. This association did not remain statistically significant in the fully adjusted model which included CRF. Low versus high CRF was associated with cognitive impairment (RR, 1.28; 95% CI, 1.07-1.53), independent of O3I and clinical biomarkers. The interaction between CRF and O3I was not significant (P = 0.8). In joint association analysis, risk of cognitive impairment was elevated with lower omega-3 index or CRF or both. Additional research is needed to fully understand the association between O3I and cognitive function at varying CRF levels.

Feasibility and acceptability of an mHealth, home-based exercise intervention in colorectal cancer survivors: A pilot randomized controlled trial

OBJECTIVE

To determine the feasibility and acceptability of an mHealth, home-based exercise intervention among stage II-III colorectal cancer (CRC) survivors within 5-years post-resection and adjuvant therapy.

METHODS

This pilot randomized controlled trial of a 12-week mHealth, home-based exercise intervention, randomly assigned CRC survivors to a high-intensity interval training (HIIT) or moderate-intensity continuous exercise (MICE) prescription. The following assessments were carried out at baseline and end-of-study (EOS): handgrip strength, short physical performance battery (SPPB), PROMIS physical function, neuropathy total symptom score-6 (NTSS-6), Utah early neuropathy scale (UENS), cardiopulmonary exercise testing, anthropometrics, and body composition via BOD POD, modified Godin leisure-time activity questionnaire. Feasibility, as defined by number of completed prescribed workouts and rate of adherence to individualized heart rate (HR) training zones, was evaluated at EOS. Acceptability was assessed by open-ended surveys at EOS. Descriptive statistics were generated for participant characteristics and assessment data.

RESULTS

Seven participants were included in this pilot study (MICE: n = 5, HIIT: n = 2). Median age was 39 years (1st quartile: 36, 3rd quartile: 50). BMI was 27.4 kg/m2 (1st quartile: 24.5, 3rd quartile: 29.7). Most participants had stage III CRC (71%, n = 5). We observed an 88.6% workout completion rate, 100% retention rate, no adverse events, and qualitative data indicating improved quality of life and positive feedback related to ease of use, accountability, motivation, and autonomy. Mean adherence to HR training zones was 95.7% in MICE, and 28.9% for the high-intensity intervals and 51.0% for the active recovery intervals in HIIT; qualitative results revealed that participants wanted to do more/work-out harder.

CONCLUSION

An mHealth, home-based delivered exercise intervention, including a HIIT prescription, among stage II-III CRC survivors' post-resection and adjuvant therapy was tolerable and showed trends towards acceptability.

Association between cardiorespiratory fitness and low back pain is anxiety-dependent: A prospective cohort study among adults and older adults

To investigate the relationship between low back pain and cardiorespiratory fitness (CRF) among participants with and without self-report anxiety. Participants were 13,080 individuals (86.6% men; 44.7 ± 9.3 years). CRF was quantified as maximal treadmill test duration and was grouped for analysis as low (lowest 20% of treadmill test duration), moderate (middle 40%), and high (upper 40%). Cox regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) between low back pain and CRF according to the presence/absence of self-report anxiety. During an average of 5.7 ± 5.1 years of follow-up, 2,965 cases of low back pain were identified. Participants with self-report anxiety and low CRF had 3.7 times (HR: 3.7; 95%CI: 1.7-8.2) more risk for having low back pain when compared with participants with self-report anxiety and high CRF. Additionally, among participants with self-reported anxiety, moderate CRF was associated with an 70% greater risk of having low back pain than those with high CRF (HR: 1.7; 95%CI: 1.1-3.2). For participants without self-reported anxiety, no association was found between the risk of having low back pain and CRF. According to the results identified in the present study, participants with self-reported anxiety who had low and moderate CRF had higher risks of low back pain than those with high CRF.

Plasma-derived extracellular vesicles released after endurance exercise exert cardioprotective activity through the activation of antioxidant pathways

Cardiovascular diseases (CVD) can cause various conditions, including an increase in reactive oxygen species (ROS) levels that can decrease nitric oxide (NO) availability and promote vasoconstriction, leading to arterial hypertension. Physical exercise (PE) has been found to be protective against CVD by helping to maintain redox homeostasis through a decrease in ROS levels, achieved by increased expression of antioxidant enzymes (AOEs) and modulation of heat shock proteins (HSPs). Extracellular vesicles (EVs) circulating in the body are a major source of regulatory signals, including proteins and nucleic acids. Interestingly, the cardioprotective role of EVs released after PE has not been fully described. The aim of this study was to investigate the role of circulating EVs, obtained through Size Exclusion Chromatography (SEC) of plasma samples from healthy young males (age: 26.95 ± 3.07; estimated maximum oxygen consumption rate (VO_2max): 51.22 ± 4.85 (mL/kg/min)) at basal level (Pre_EVs) and immediately after a single bout of endurance exercise (30' treadmill, 70% heart rate (HR) -Post_EVs). Gene ontology (GO) analysis of proteomic data from isolated EVs, revealed enrichment in proteins endowed with catalytic activity in Post_EVs, compare to Pre_EVs, with MAP2K1 being the most significantly upregulated protein. Enzymatic assays on EVs derived from Pre and Post samples showed increment in Glutathione Reductase (GR) and Catalase (CAT) activity in Post_EVs. At functional level, Post_EVs, but not Pre_EVs, enhanced the activity of antioxidant enzymes (AOEs) and reduced oxidative damage accumulation in treated human iPS-derived cardiomyocytes (hCM) at basal level and under stress conditions (Hydrogen Peroxide (H₂O₂) treatment), resulting in a global cardioprotective effect. In conclusion, our data demonstrated, for the first time, that a single 30-min endurance exercise is able to alter the cargo of circulating EVs, resulting in cardioprotective effect through antioxidant activity.

Steady-state redox status in circulating extracellular vesicles: A proof-of-principle study on the role of fitness level and short-term aerobic training in healthy young males

Considering the role of redox homeostasis in exercise-induced signaling and adaptation, this study focuses on the exercise training-related intercellular communication of redox status mediated by circulating extracellular vesicles (EVs). 19 healthy young males were divided into trained (TG, 7) and untrained (UG, 12) subjects based on their VO_2MAX. The UG subjects were further randomly distributed in experimental (UG_EX, N = 7) and control (UG_CTRL, N = 5) groups. The steady state of plasma EVs in TG and UG_EX have been characterized for total number and size, as well as cargo redox status (antioxidants, transcription factors, HSPs) before, 3 and 24 h after a single bout of aerobic exercise (30', 70% HRM). Plasma EVs from UG_EX and UG_CTRL have been further characterized after 24 h from the last session of a 5-day consecutive aerobic training or no training, respectively. No differences were detected in the EVs' size and distribution at baseline in TG and UG_EX (p>0.05), while the EVs cargo of UG_EX showed a significantly higher concentration of protein carbonyl, Catalase, SOD2, and HSF1 compared to TG (p<0.05). 5 days of consecutive aerobic training in UG_EX did not determine major changes in the steady-state number and size of EVs. The post-training levels of protein carbonyl, HSF1, Catalase, and SOD2 in EVs cargo of UG_EX resulted significantly lower compared with UG_EX before training and UG_CTRL, resembling the steady-state levels in circulating EVs of TG subjects. Altogether, these preliminary data indicate that individual aerobic capacity influences the redox status of circulating EVs, and that short-term aerobic training impacts the steady-state redox status of EVs. Taking this pilot study as a paradigm for physio-pathological stimuli impacting redox homeostasis, our results offer new insights into the utilization of circulating EVs as biomarkers of exercise efficacy and of early impairment of oxidative-stress related diseases.

Associations among cardiorespiratory fitness, C-reactive protein, and all-cause mortality in men and women

We examined individual and joint associations among high-sensitivity C-reactive protein (CRP), cardiorespiratory fitness (fitness), and mortality in healthy men and women. Between January 1, 2000 and December 31, 2016, 30,077 adults (31.3% women) received a comprehensive physical examination. Fitness was determined from maximal treadmill exercise test duration. Participants were categorized as unfit (Quintile 1) and fit (Quintiles 2-5), and by normal (<2 mg/L) and elevated (≥2 mg/L) CRP categories. Adjusted hazard ratios (HRs) with 95% confidence interval (CI) for all-cause mortality were computed with Cox regression. During an average of 10.1 years of follow-up, 576 deaths occurred. Following adjustment for age, smoking status, sex, exam year, body mass index, systolic blood pressure, total cholesterol, triglyceride:high-density lipoprotein ratio, and fasting glucose, HR (95% CI) for all-cause mortality were 1.0 (referent) and 1.52 (1.14-2.02) for fit and unfit categories, respectively. Corresponding values for normal and elevated CRP categories were 1.0 and 1.50 (1.20-1.89), respectively. When grouped by fitness and CRP category, there was significantly greater mortality risk in the unfit than the fit category within the elevated CRP category (HR = 1.77 (1.14-2.75)), but not in the normal CRP category (HR = 1.38 (0.96-1.98)). Each 1 metabolic equivalent increment in fitness and 1 mg/L increment in CRP were associated with 10.0% (95% CI: 5.1-14.8%) decreased and 7.3% (95% CI: 2.0%-12.9%) increased mortality hazard, respectively. Compared to the unfit, fit individuals have an attenuated mortality risk within each CRP category. Thus, higher fitness appears to provide some protection against all-cause mortality, particularly among those with elevated levels of inflammation.

Blood Pressure Responses During Exercise: Physiological Correlates and Clinical Implications

BACKGROUND

Abnormal blood pressure (BP) responses to exercise can predict adverse cardiovascular outcomes, but their optimal measurement and definitions are poorly understood. We combined frequently sampled BP during cardiopulmonary exercise testing with vascular stiffness assessment to parse cardiac and vascular components of exercise BP.

METHODS

Cardiopulmonary exercise testing with BP measured every two minutes and resting vascular tonometry were performed in 2858 Framingham Heart Study participants. Linear regression was used to analyze sex-specific exercise BP patterns as a function of arterial stiffness (carotid-femoral pulse wave velocity) and cardiac-peripheral performance (defined by peak O2 pulse).

RESULTS

Our sample was balanced by sex (52% women) with mean age 54±9 years and 47% with hypertension. We observed variability in carotid-femoral pulse wave velocity and peak O2 pulse across individuals with clinically defined exercise hypertension (peak systolic BP [SBP] in men ≥210 mm Hg; in women ≥190 mm Hg). Despite similar resting SBP and cardiometabolic profiles, individuals with higher peak O2 pulse displayed higher peak SBP (P≤0.017) alongside higher fitness levels (P<0.001), suggesting that high peak exercise SBP in the context of high peak O2 pulse may in fact be favorable. Although both higher (favorable) O2 pulse and higher (adverse) arterial stiffness were associated with greater peak SBP (P<0.0001 for both), the magnitude of association of carotid-femoral pulse wave velocity with peak SBP was higher in women (sex-carotid-femoral pulse wave velocity interaction P<0.0001). In sex-specific models, exercise SBP measures accounting for workload (eg, SBP during unloaded exercise, SBP at 75 watts, and SBP/workload slope) were directly associated with the adverse features of greater arterial stiffness and lower peak O2 pulse.

CONCLUSIONS

Higher peak exercise SBP reflects a complex trade-off between arterial stiffness and cardiac-peripheral performance that differs by sex. Studies of BP responses to exercise accounting for vascular and cardiac physiology may illuminate mechanisms of hypertension and clarify clinical interpretation of exercise BP.

High-Intensity Interval Training Versus Moderate-Intensity Continuous Training for Improving Physical Health in Elderly Women

In elderly women, a lack of regular physical exercise may result in faster decreases in general health and functional performance. Although high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) have been effectively applied in young and clinical groups, there is no evidence to support their use in elderly women to achieve health benefits. Thus, the major goal of this study was to investigate how HIIT affected health-related outcomes in elderly women. Twenty-four inactive elderly women agreed to participate in the 16-week HIIT and MICT intervention. Body composition, insulin resistance, blood lipids, functional capacity, cardiorespiratory fitness, and quality of life were all measured before and after the intervention. The number of differences between groups was determined using Cohen's effect sizes, and the pre-post intra-group changes were compared using paired t-tests. Using 2 × 2 ANOVA, the time × group interaction effects between HIIT and MICT were evaluated. Body fat percentage, sagittal abdominal diameter, waist circumference, and hip circumference all were improved significantly in the 2 groups. HIIT substantially improved fasting plasma glucose and cardiorespiratory fitness as compared to the MICT. HIIT improved the lipid profile and functional ability more significantly compared to the MICT group. These findings show that HIIT is a useful exercise for improving elderly women's physical health.

Normal reference values for aerobic fitness in cystic fibrosis: a scoping review

Objective

The importance of aerobic fitness (VO2peak) in cystic fibrosis (CF) is well established, and regular exercise testing is recommended. To standardise VO2peak, a ‘percentage of predicted’ (%pred) derived from normative reference values (NRV), as promoted by the 2015 European Cystic Fibrosis Society Exercise Working Group (ECFS EWG), can be reported. However, the NRVs used in CF and their relative frequency is unknown.

Method

A scoping review was performed via systematic database searches (PubMed, Embase, Web of Science, SciELO, EBSCO) and forward citation searches for studies that include people with CF and report VO2peakas %pred. Studies were screened using Covidence, and data related to patient demographics, testing modality and reference equations were extracted. Additional analyses were performed on studies published in 2016–2021, following the ECFS EWG statement in 2015.

Results

A total of 170 studies were identified, dating from 1984 to 2022, representing 6831 patients with CF, citing 34 NRV. Most studies (154/170) used cycle ergometry, 15/170 used treadmills, and the remainder used alternative, combination or undeclared modalities. In total, 61/170 failed to declare the NRV used. There were 61 studies published since the ECFS EWG statement, whereby 18/61 used the suggested NRV.

Conclusion

There is a wide discrepancy in NRV used in the CF literature base to describe VO2peakas %pred, with few studies using NRV from the ECFS EWG statement. This high variance compromises the interpretation and comparison of studies while leaving them susceptible to misinterpretation and limiting replication. Standardisation and alignment of reporting of VO2peakvalues are urgently needed.

Cardiorespiratory Fitness and Depression Symptoms among Adults During the COVID-19 Pandemic: Cooper Center Longitudinal Study

This study examined the relation between cardiorespiratory fitness (fitness) and depression symptoms prior to and during COVID-19 among adults seeking preventive medical care. Participants consisted of 967 patients attending the Cooper Clinic (Dallas, TX) pre-pandemic (March 2018-December 2019) and during the pandemic (March-December 2020). The outcome, depression symptoms, was based on the Center for Epidemiological Studies-Depression (CES-D). Maximal metabolic equivalents task (MET) levels for fitness were determined from the final treadmill speed and grade. Multiple linear regression models were computed by sex. Analysis revealed that mean fitness decreased from 11.4 METs (SD=2.1) prior to the pandemic to 10.9 METs (SD=2.3) during the pandemic (p-value<0.001). The mean CES-D score increased from 2.8 (SD= 3.1) before to pandemic to 3.1 (SD=3.2) during the pandemic (p-value=0.003). Results from multiple linear regression indicate that increased fitness was associated with a statistically significant decrease in depression scores in men (-0.17 per MET; 95%CI -0.33, -0.02) but not women. This modest decrease may have been tempered by high fitness levels and low depression scores at baseline in this well-educated sample.

Effects of acute exercise on memory: Considerations of exercise intensity, post-exercise recovery period and aerobic endurance

Accumulating research demonstrates that acute exercise can enhance long-term episodic memory. However, it is unclear if there is an intensity-specific effect of acute exercise on long-term episodic memory function and whether this is influenced by the post-exercise recovery period, which was the primary objective of this experiment. Another uncertainty in the literature is whether aerobic endurance influences the interaction between exercise intensity and post-exercise recovery period on long-term episodic memory function, which was a secondary objective of this study. With exercise intensity and post-exercise recovery period occurring as within-subject factors, and fitness as a between-subject factor, 59 participants (M_age = 20 years) completed 12 primary laboratory visits. These visits included a 20-min bout of exercise (Control, Moderate, and Vigorous), followed by a recovery period (1, 5, 10, and 15 min) and then a word-list episodic memory task, involving an encoding phase and two long-term recall assessments (20-min and 24-h delayed recall). The primary finding from this experiment was that moderate and vigorous-intensity exercise improved memory function when compared to a non-exercise control. A secondary finding was that individuals with higher levels of aerobic endurance, compared to their lesser fit counterparts, had greater memory performance after exercise (moderate or vigorous) when compared to after a control condition. Additionally, individuals with higher levels of aerobic endurance, compared to their lesser fit counterparts, generally performed better on the memory task with longer post-exercise recovery periods. Future research should carefully consider these parameters when evaluating the effects of acute exercise on long-term episodic memory.

Estimating Cardiorespiratory Fitness Without Exercise Testing or Physical Activity Status in Healthy Adults: Regression Model Development and Validation

Background

Low cardiorespiratory fitness (CRF) is an independent predictor of morbidity and mortality. Most health care settings use some type of electronic health record (EHR) system. However, many EHRs do not have CRF or physical activity data collected, thereby limiting the types of investigations and analyses that can be done.

Objective

This study aims to develop a nonexercise equation to estimate and classify CRF (in metabolic equivalent tasks) using variables commonly available in EHRs.

Methods

Participants were 42,676 healthy adults (female participants: n=9146, 21.4%) from the Aerobics Center Longitudinal Study examined from 1974 to 2005. The nonexercise estimated CRF was based on sex, age, measured BMI, measured resting heart rate, measured resting blood pressure, and smoking status. A maximal treadmill test measured CRF.

Results

After conducting nonlinear feature augmentation, separate linear regression models were used for male and female participants to calculate correlation and regression coefficients. Cross-classification of actual and estimated CRF was performed using low CRF categories (lowest quintile, lowest quartile, and lowest tertile). The multiple correlation coefficient (R) was 0.70 (mean deviation 1.33) for male participants and 0.65 (mean deviation 1.23) for female participants. The models explained 48.4% (SE estimate 1.70) and 41.9% (SE estimate 1.56) of the variance in CRF for male and female participants, respectively. Correct category classification for low CRF (lowest tertile) was found in 77.2% (n=25,885) of male participants and 74.9% (n=6,850) of female participants.

Conclusions

The regression models developed in this study provided useful estimation and classification of CRF in a large population of male and female participants. The models may provide a practical method for estimating CRF derived from EHRs for population health research.

Long-term Cardiovascular Risk in Astronauts: Comparing NASA Mission Astronauts With a Healthy Cohort From the Cooper Center Longitudinal Study

OBJECTIVE

To determine the long-term cardiovascular disease risk of astronauts with spaceflight exposure compared with a well-matched cohort.

METHODS

National Aeronautics and Space Administration (NASA) astronauts are selected into their profession based upon education, unique skills, and health and are exposed to cardiovascular disease risk factors during spaceflight. The Cooper Center Longitudinal Study (CCLS) is a generally healthy cohort from a preventive medicine clinic in Dallas, Texas. Using a matched cohort design, astronauts who were selected beginning April 1, 1959, (and each subsequent selection class through 2009) and exposed to spaceflight were matched to CCLS participants who met astronaut selection criteria; 1514 CCLS participants matched to 303 astronauts in a 5-to-1 ratio on sex, date of birth, and age. The outcome of cardiovascular mortality through December 31, 2016, was determined by death certificate or National Death Index.

RESULTS

There were 11 deaths caused by cardiovascular disease (CVD) among astronauts and 46 among CCLS participants. There was no evidence of increased mortality risk in astronauts (hazard ratio [HR]=1.10; 95% confidence interval [CI], 0.50 to 2.45) with adjustment for baseline cardiovascular covariates. However, the secondary outcome of CVD events showed an increased adjusted risk in astronauts (HR=2.41; 95% CI, 1.26 to 4.63).

CONCLUSION

No increased risk of CVD mortality was observed in astronauts with spaceflight exposure compared with a well-matched cohort, but there was evidence of increased total CVD events. Given that the duration of spaceflight will increase, particularly on missions to Mars, continued surveillance and mitigation of CVD risk is needed to ensure the safety of those who venture into space.

Maximal Aerobic Power Using the Modified Heck Protocol: Prediction Models

The purpose of this study was to develop prediction models based on an incremental treadmill test to volitional exhaustion utilizing the modified Heck protocol. A total of 598 professional and youth athletes participating in different sports were recruited for this study. Specifically, the study enrolled professional male soccer players (n=380), professional male futsal players (n=24), elite male basketball players (n=27), professional male soccer referees (n=50), elite female soccer players (n=19), youth male basketball players (13-14 yrs n=15, 15-17 yrs n=20) and youth male soccer players (15 yrs n=28, 16-17 yrs n=35). Anthropometric measurements included stature, body mass, and body fat. Furthermore, all participants performed incremental cardiopulmonary exercise testing on a treadmill using the modified Heck protocol. Through multiple regression analysis, a separate prediction model was developed for each of the athletic populations. Results demonstrated that a significant (p=0.001) proportion of the variation observed in VO₂max was explained by the variation in running time. The generated VO₂max regression equations would allow athletes and coaches to predict VO₂max in a relatively short time without the need for expensive and sophisticated equipment. To our knowledge, this is the first study that provides regression models for different athletic populations using the modified Heck protocol.

Relationship between Health-Related Physical Fitness Parameters and Functional Movement Screening Scores Acquired from a Three-Dimensional Markerless Motion Capture System

The purpose of the present study was to examine the relationship between five algorithm-derived functional movement screening scores (i.e., readiness, explosiveness, functionality, dysfunction, and vulnerability) obtained from an innovative three-dimensional markerless motion capture system (3D-MCS) and some of the key health-related physical fitness parameters such as maximal aerobic capacity (VO₂max), body mass index (BMI), body fat percentage (BF%), waist and hip circumferences (WC and HC), and high-density lipoprotein cholesterol (HDL-C). BF% showed a weak positive correlation with vulnerability and moderate-to-strong negative correlations with readiness, explosiveness, and functionality scores. Similarly, but opposite to BF%, VO₂max showed a weak negative correlation with vulnerability and moderate-to-strong positive correlations with readiness, explosiveness, and functionality scores. BMI, WC, and HC showed moderate negative correlations with vulnerability, readiness, and functionality scores, while HDL-C showed a weak positive correlation with vulnerability and a weak negative correlation with explosiveness scores. Therefore, it appears that 3D-MCS may be used a as a non-invasive testing alternative or in conjunction with currently implemented traditional testing modalities to provide health practitioners with additional information regarding some of the key health-related physical fitness parameters, especially within non-academic environments such as wellness and clinical settings.

Comparison of time-matched aerobic, resistance or combined exercise training in women living with obesity: a protocol for a pilot randomised controlled trial—the EXOFFIT (Exercise for Obesity in Females to increase Fitness) study

Introduction

Obesity in women has more than doubled in the past thirty years. Increasing research suggests that increased cardiorespiratory fitness (CRF) can largely attenuate the negative health risks associated with obesity. Though previous literature suggests that combined training may be the most effective for improving CRF in adults with obesity, there is minimal research investigating the efficacy of combined and resistance programmes in women with obesity. This article outlines a protocol for a parallel pilot study which aims to evaluate the feasibility and efficacy of three exercise modalities in women with obesity for increasing CRF and strength and improving body composition and other health outcomes (i.e. quality of life).

Methods and analysis

Sixty women (aged 18–50) with obesity (body mass index [BMI] ≥ 30 and/or waist circumference ≥ 88 cm) who are physically inactive, have no unstable health conditions and are safe to exercise will be recruited from September 2021 to December 2022. The main outcome will be feasibility and acceptability of the intervention and procedures. Trial feasibility outcomes will be evaluated to determine if a definitive trial should be undertaken. Trial acceptability will be explored through follow-up qualitative interviews with participants. Secondary outcomes will include CRF (predicted VO₂ max), anthropometrics (i.e. BMI), strength (5RM bench press, leg dynamometry, grip strength) and other health outcomes (i.e., pain). Participants will be block randomised into one of four trial arms (aerobic exercise, resistance training and combined training groups, non-active control group) and measurements will be completed pre- and post-intervention. The exercise groups will receive an individualised supervised exercise programme for 3× sessions/week for 12 weeks. The change in mean values before and after intervention will be calculated for primary and secondary outcomes. ANOVA and t-tests will be applied to evaluate within-group and between-group differences. If sufficient participants are recruited, the data will be analysed using ANCOVA with the age and BMI as covariates.

Discussion

This pilot will provide data on the feasibility and acceptability of trial procedures and of the programmes’ three progressive time-matched exercise interventions (aerobic, resistance and combined) for women living with obesity, which will help inform future research and the potential development of a full-scale randomised clinical trial.

Trial registration

ISRCTN, ISRCTN13517067. Registered 16 November 2021—retrospectively registered.

A Comparison of the Validity of Three Exercise Tests for Estimating Maximal Oxygen Uptake in Korean Adults Aged 19–64 Years

The purpose of this study was to compare the validity of three submaximal exercise tests (SMETs) and develop practical predictive models for the VO2max in Korean adults. A total of 541 (287 males and 254 females) adults participated in this study. Their ages ranged from 19 to 64. The VO2max was measured using the maximal-graded exercise treadmill test. The SMETs were performed by a treadmill test, the YMCA step test, and the PACER test. Regression analysis was conducted to compare the validity of the VO2max predictive equations using SMETs. The validity of the predictive models was evaluated using explanatory power, standard error of estimate (SEE), and Bland-Altman analysis. The explanatory power between the measured VO2max and the predicted VO2max was 58.0% (<0.001), 59.2% (<0.001), and 71.7% (<0.001), respectively. The SEEs were 4.545, 4.478, and 3.732 (mL/kg/min). The models were significant predictors of VO2max and had acceptable validity in a large sample of Korean adults. Especially, among the predictive models, PACER had the highest acceptable effectiveness. Therefore, the equations developed in this study are recommended to better evaluate the cardiovascular endurance of Korean adults.

Fit and Tipsy? The Interrelationship between Cardiorespiratory Fitness and Alcohol Consumption and Dependence

PURPOSE

To examine whether higher levels of cardiorespiratory fitness are related to increased alcohol consumption and dependence among a large sample of adults attending a preventive medicine clinic.

METHODS

A cross-sectional study of 38,653 apparently healthy patients who visited the Cooper Clinic (Dallas, TX) for preventive medical examinations (1988-2019) and enrolled in the Cooper Center Longitudinal Study. The primary independent variable was cardiorespiratory fitness, based on a maximal treadmill test, and the dependent variables were alcohol consumption and dependence (self-reported). The relations between fitness category (low, moderate, high) and alcohol consumption (low, moderate, heavy) and suggested alcohol dependence (Cut down, Annoyed, Guilty, Eye opener score ≥2) among women and men were estimated via multivariable regression while adjusting for covariates (e.g., age, birth year cohort, marital status, and body mass index).

RESULTS

Women within the moderate and high fitness categories had 1.58 (95% confidence interval [CI], 1.32-1.91) and 2.14 (95% CI, 1.77-2.58) greater odds of moderate/heavy alcohol consumption, respectively, in comparison to their low fitness counterparts. Similarly, moderate and high fit men had 1.42 (95% CI, 1.30-1.55) and 1.63 (95% CI, 1.49-1.80) times greater odds of moderate-to-heavy alcohol consumption, respectively, in comparison to the low fitness group. In addition, among men who were heavy drinkers (but not women), higher fitness levels were related to lower rates of suggested alcohol dependence. Specifically, these men had 45.7%, 41.7%, and 34.9% proportions of clinically relevant alcohol problems across low, moderate, and high fitness categories (adjusted P for trend <0.001).

CONCLUSIONS

Higher fitness levels are significantly related to greater alcohol consumption among a large cohort of adult patients. Interventions focusing on increasing fitness (via physical activity promotion) might consider concurrently aiming to reduce alcohol consumption.

Change in Metabolic Syndrome and Cardiorespiratory Fitness Following Exercise Training - The Ball State Adult Fitness Longitudinal Lifestyle Study (BALL ST)

PURPOSE

To evaluate how the changes in directly measured cardiorespiratory fitness (CRF) relate to the changes in metabolic syndrome (MetS) status following 4-6 months of exercise training.

METHODS

Maximal cardiopulmonary exercise (CPX) tests and MetS risk factors were analyzed prospectively from 336 adults (46% women) aged 45.8 ± 10.9 years. MetS was defined according to the National Cholesterol Education Program-Adult Treatment Panel III criteria, as updated by the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI). Pearson correlations, chi-squares, and dependent 2-tail t-tests were used to assess the relationship between the change in CRF and the change in MetS risk factors, overall number of MetS risk factors, and a MetS severity score following 4-6 months of participation in a self-referred, community-based exercise program.

RESULTS

Overall prevalence of MetS decreased from 23% to 14% following the exercise program (P < 0.05), while CRF improved 15% (4.7 ± 8.4 mL/kg/min, P < 0.05). Following exercise training, the number of positive risk factors declined from 1.4 ± 1.3 to 1.2 ± 1.2 in the overall cohort (P < 0.05). The change in CRF was inversely related to the change in the overall number of MetS risk factors (r = -0.22; P < 0.05) and the MetS severity score (r = -0.28; p < 0.05).

CONCLUSION

This observational cohort study indicates an inverse relationship between the change in CRF and the change in MetS severity following exercise training. These results suggest that participation in a community-based exercise program yields significant improvements in CRF, MetS risk factors, the prevalence of the binary MetS, and the MetS severity score. Improvement in CRF through exercise training should be a primary prevention strategy for MetS.

Differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability in athletes and non-athletes

The study investigated the differential response to a single bout of maximal incremental treadmill exercise between athletes and non-athletes without dry eyes regarding tear secretion, tear film stability, visual acuity (VA), and stereoacuity. Additionally, the study examined the effect of gender and the duration of exercise on exercise-induced changes. Study participants included young university students aged 18-25 years who were athletes (male/female: 13/13) or non-athletes (male/female: 17/9). Participants underwent an aerobic exercise session using a treadmill and following the laid down Bruce treadmill test protocol till exhaustion. Measurements were taken in the order of distance VA, stereopsis, non-invasive tear break-up time (TBUT), and phenol red thread test, at baseline and after the exercise regimen. Within- and between-subject analyses using multiple t-tests with correction for multiple comparisons were performed to determine differences before and after exercise in athletes and non-athletes. Subsequently, ANCOVA was used to assess the influence of gender and the duration of exercise. The mean age (SD) of the athletes and the non-athletes was 22.4 ± 2.1 years and 21.8 ± 2.1 years, respectively (p = 0.357). Before exercise, the athletes had higher TBUT than non-athletes (14.6 ± 2.9 s vs. 11.9 ± 3.8 s; p = 0.021), but no difference was observed in any other ocular measurements. After exercise, the athletes showed significant improvement in tear secretion with the basal tear secretion increasing from 22.3 ± 2.5 mm to 25.8 ± 1.7 mm (p < 0.001). The non-athletes on the other hand had a borderline increase in tear secretion from 21.42 ± 2.85 mm to 23.73 ± 2.68 mm (p = 0.08). Also, the TBUT was much improved in the athletes after exercise compared to the non-athletes (17.7 ± 2.7 s vs. 14.8 ± 2.9 s, p = 0.004). Additionally, exercise improved the VA indifferently between the groups, while stereoacuity was unchanged after exercise in either group. Gender had no influence on the differences in the tear function measures between athletes and non-athletes after exercise. The duration of exercise, however, showed a borderline effect on the tear film stability (p = 0.068) after exercise. Our findings support the differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability between athletes and non-athletes. Thus, increased physical fitness and the duration of exercise might be crucial in the improvement of tear function through aerobic exercise.

Improvement in functional capacity with spironolactone masks the treatment effect on exercise blood pressure

OBJECTIVES

A hypertensive response to submaximal exercise is associated with cardiovascular disease but this relationship is influenced by functional capacity. Spironolactone improves functional capacity, which could mask treatment effects on exercise blood pressure. This study sought to examine this hypothesis.

DESIGN

Retrospective analysis of a randomized clinical trial.

METHODS

102 participants (54 ± 9 years; 52% male) with a hypertensive response to maximal exercise (systolic BP ≥210 mm Hg men; ≥190 mm Hg women) were randomized to 3-month spironolactone 25 mg daily (n = 53) or placebo (n = 49). Submaximal exercise blood pressure was measured during low-intensity cycling (50, 60 or 70% age-predicted maximal heart rate). Functional capacity was measured as maximal oxygen capacity obtained during a maximal treadmill exercise test, and (resting) aortic stiffness by carotid-to-femoral pulse wave velocity.

RESULTS

Spironolactone improved submaximal exercise systolic blood pressure vs. placebo (-4 ± 16 vs. 2 ± 15 mm Hg, p = 0.045, Cohen's d = 0.42), and had a small (but non-statistically significant) improvement in functional capacity (0.64 ± 5.10 vs. -1.43 ± 5.04 ml/kg/min, p = 0.06, Cohen's d = 0.4). When treatment effects were expressed as the change in submaximal exercise systolic blood pressure relative to the change in functional capacity, a larger effect size was observed (-0.3 ± 1.1 vs. 0.3 ± 1.1 mm Hg/ml·kg·min^-1, p = 0.01, Cohen's d = 0.58), but was not explained by improved aortic stiffness.

CONCLUSIONS

Spironolactone reduces submaximal exercise blood pressure, but this treatment effect may be hidden by improved functional capacity and a non-fixed workload. This highlights the most clinically relevant exercise blood pressure is at a low intensity and fixed workload where the influence of fitness on exercise blood pressure is removed, and the effects of therapy can be appreciated.

Body mass, cardiorespiratory fitness, and cardiometabolic risk over time: Findings from the Cooper Center Longitudinal Study

Few studies have adequately assessed the simultaneous effects of changes in cardiorespiratory fitness (fitness) and body mass on cardiometabolic risk. Hence, the current study's aims were twofold: (1) To determine whether increases in body mass result in higher cardiometabolic risk after controlling for fitness changes; and (2) To assess whether increases in fitness result in lower cardiometabolic risk after controlling for weight changes. The study consisted of 3534 patients who came for preventive medicine visits ≥4 times over any 10-year period (1979-2019). The primary independent variables were body mass and fitness, and the dependent variable was metabolic syndrome (MetS) and its components. Mixed-effects regression was used to model the relationship between changes in body mass, fitness, and MetS. Results indicate that increasing body mass up to a 10-year period was significantly related to increasing risk of MetS while controlling for changes in fitness. Specifically, a 1-kg increase in body mass was associated with a 17% (OR = 1.17; 95% CI 1.15-1.19) increased odds for MetS, while adjusting for fitness changes. A 1-MET increase in fitness was related to a 23% (OR = 0.77; 95% CI 0.70-0.84) decrease in odds for MetS, while adjusting for body mass changes up to 10 years. Moreover, body mass change was significantly related to changes in all cardiometabolic components of MetS. Fitness change was significantly associated with changes in MetS components. Future interventions should focus concurrently on increasing fitness and on body mass loss (or maintenance) to improve cardiometabolic health.

The association of fitness and fatness with intermediate hyperglycemia incidence in women: A cohort study

The purpose of this study was to examine the associations of cardiorespiratory fitness, general adiposity, and central adiposity with incident intermediate hyperglycemia (IH) in women. We conducted a prospective cohort study of 1534 women aged 20-79 years old who had an annual health check-up with no history of major chronic diseases. At baseline, fitness was assessed by a Balke graded exercise test, and the estimated metabolic equivalents were used to create quartile groups. Women were also grouped based on their body mass index (<25 kg/m², 25-29.9 kg/m², and ≥ 30 kg/m²) and waist-to-height ratio (≥0.50 or < 0.50). Cox proportional hazards models were conducted to assess the association of fitness and fatness variables with incident IH defined as fasting glucose of 5.6-6.9 mmol/L. Overall, 18.1% (n = 277) of the women developed IH during an average follow-up of 5.06 years. Fitness, body mass index, and waist-to-height ratio at baseline were the independent predictors of the IH incidence in separate age-adjusted models; yet when all three variables were included in the same model along with confounding variables, only fitness remained significant and demonstrated a clear inverse association with incident IH (P-for-trend <0.001). Health promotion efforts should focus on improving fitness for the prevention of IH in women.

Prediction of Exercise Capacity and Training Prescription from the 6-Minute Walk Test and Rating of Perceived Exertion

Walking tests, such as the 6-min walk test (6MWT), are popular methods of estimating peak oxygen uptake (VO₂peak) in clinical populations. However, the strength of the distance vs. VO₂peak relationship is not strong, and there are no equations for estimating ventilatory threshold (VT), which is important for training prescription and prognosis. Since the 6MWT is often limited by walking mechanics, prediction equations that include simple additional predictors, such as the terminal rating of perceived exertion (RPE), hold the potential for improving the prediction of VO₂max and VT. Therefore, this study was designed to develop equations for predicting VO₂peak and VT from performance during the 6MWT, on the basis of walking performance and terminal RPE. Clinically stable patients in a cardiac rehabilitation program (N = 63) performed the 6MWT according to the American Thoracic Society guidelines. At the end of each walk, the subject provided their terminal RPE on a 6-20 Borg scale. Each patient also performed a maximal incremental treadmill test with respiratory gas exchange to measure VO₂peak and VT. There was a good correlation between VO₂peak and 6MWT distance (r = 0.80) which was improved by adding the terminal RPE in a multiple regression formula (6MWT + RPE, R² = 0.71, standard error of estimate, SEE = 1.3 Metabolic Equivalents (METs). The VT was also well correlated with walking performance, 6MWT distance (r = 0.80), and was improved by the addition of terminal RPE (6MWT + RPE, R² = 0.69, SEE = 0.95 METs). The addition of terminal RPE to 6MWT distance improved the prediction of maximal METs and METs at VT, which may have practical applications for exercise prescription.

Astaxanthin supplementation enhances metabolic adaptation with aerobic training in the elderly

Endurance training (ET) is recommended for the elderly to improve metabolic health and aerobic capacity. However, ET-induced adaptations may be suboptimal due to oxidative stress and exaggerated inflammatory response to ET. The natural antioxidant and anti-inflammatory dietary supplement astaxanthin (AX) has been found to increase endurance performance among young athletes, but limited investigations have focused on the elderly. We tested a formulation of AX in combination with ET in healthy older adults (65-82 years) to determine if AX improves metabolic adaptations with ET, and if AX effects are sex-dependent. Forty-two subjects were randomized to either placebo (PL) or AX during 3 months of ET. Specific muscle endurance was measured in ankle dorsiflexors. Whole body exercise endurance and fat oxidation (FATox) was assessed with a graded exercise test (GXT) in conjunction with indirect calorimetry. Results: ET led to improved specific muscle endurance only in the AX group (Pre 353 ± 26 vs. Post 472 ± 41 contractions), and submaximal GXT duration improved in both groups (PL 40.8 ± 9.1% and AX 41.1 ± 6.3%). The increase in FATox at lower intensity after ET was greater in AX (PL 0.23 ± 0.15 g vs. AX 0.76 ± 0.18 g) and was associated with reduced carbohydrate oxidation and increased exercise efficiency in males but not in females.

Validation of a Modified Submaximal Balke Protocol to Assess Cardiorespiratory Fitness in Individuals at High Risk of or With Chronic Health Conditions-A Pilot Study

Objectives: This study aims to validate a submaximal treadmill walking test for estimation of maximal oxygen consumption (VO_2max) in individuals at high risk of or with chronic health conditions. Method: Eighteen participants (age 62 ± 16 years; VO_2max 31.2 ± 5.9 ml kg^-1 min^-1) at high risk of getting or with established chronic diseases performed two valid modified Balke treadmill walking protocols, one submaximal protocol, and one maximal protocol. Test duration, heart rate (HR), and rate of perceived exertion (RPE) were measured during both tests. VO_2max was measured during the maximal test. VO_2max was estimated from the submaximal test by multiple regression using time to RPE ≥ 17, gender, age, and body mass as independent variables. Model fit was reported as explained variance (R ²) and standard error of the estimate (SEE). Results: The model fit for estimation of VO_2max from time to RPE ≥ 17 at the submaximal test, body mass, age, and gender was R ² = 0.78 (SEE = 3.1 ml kg^-1 min^-1, p ≤ 0.001). Including heart rate measurement did not improve the model fit. Conclusions: The submaximal walking test is feasible and valid for assessing cardiorespiratory fitness in individuals with high risk of or chronic health conditions.

Longitudinal Associations of Fitness and Obesity in Young Adulthood With Right Ventricular Function and Pulmonary Artery Systolic Pressure in Middle Age: The CARDIA Study

Background Low cardiorespiratory fitness (CRF) and obesity are risk factors for heart failure but their associations with right ventricular (RV) systolic function and pulmonary artery systolic pressure (PASP) are not well understood. Methods and Results Participants in the CARDIA (Coronary Artery Risk Development in Young Adults) study who underwent maximal treadmill testing at baseline and had a follow-up echocardiographic examination at year 25 were included. A subset of participants had repeat CRF and body mass index (BMI) assessment at year 20. The associations of baseline and changes in CRF and BMI on follow-up (baseline to year 20) with RV systolic function parameters (tricuspid annular plane systolic excursion, RV Doppler systolic velocity of the lateral tricuspid annulus), and PASP were assessed using multivariable-adjusted linear regression models. The study included 3433 participants. In adjusted analysis, higher baseline BMI but not CRF was significantly associated with higher PASP. Among RV systolic function parameters, higher baseline CRF and BMI were significantly associated with higher tricuspid annular plane systolic excursion and RV systolic velocity of the lateral tricuspid annulus. In the subgroup of participants with follow-up assessment of CRF or BMI at year 20, less decline in CRF was associated with higher RV systolic velocity of the lateral tricuspid annulus and lower PASP, while greater increase in BMI was significantly associated with higher PASP in middle age. Conclusions Higher CRF in young adulthood and less decline in CRF over time are each significantly associated with better RV systolic function. Higher baseline BMI and greater age-related increases in BMI are each significantly associated with higher PASP in middle age. These findings provide insights into possible mechanisms through which low fitness and obesity may contribute toward risk of heart failure.

Adherence to a lower versus higher intensity physical activity intervention in the Breast Cancer & Physical Activity Level (BC-PAL) Trial

PURPOSE

The first aim is to examine adherence to a lower versus higher intensity physical activity (PA) prescription in breast cancer survivors in the Breast Cancer & Physical Activity Level (BC-PAL) Trial. The second aim is to assess associations between baseline characteristics with mean PA adherence in both intervention groups combined.

METHODS

Forty-five participants were randomized to a 12-week, home-based lower (300 min/week, 40-59% heart rate reserve (HRR)) or higher (150 min/week, 60-80% HRR) intensity PA intervention, or no intervention/control. Both intervention groups received Polar A360® trackers and were included in this analysis (n=30). Study outcomes assessed on a weekly basis with the Polar A360® activity tracker throughout the intervention included relative adherence to the prescribed PA interventions (% of PA prescription goal met), and the absolute amount of PA time ≥40% of HRR. Baseline predictors of adherence included demographic characteristics, cardiorespiratory fitness, habitual PA and sedentary time, quality of life measures, and motivational variables from the Theory of Planned Behavior. For our primary aim, a linear mixed model was used to assess the effects of randomization group, time (intervention weeks 1-12), and the interaction of these factors on the natural logarithm of PA adherence. For our secondary aim, the association between each baseline predictor with the natural logarithm of mean weekly PA adherence was assessed, with randomization group added as a covariate.

RESULTS

Higher relative time within the prescribed HRR zone was noted in the lower versus higher intensity PA groups (e^β=3.12, 95% CI=1.97, 4.95). No differences in adherence across time were noted. Social support was inversely associated with relative PA time within the prescribed HRR zone (e^β=0.83, 95% CI=0.72, 0.97) and absolute PA time ≥40% of HRR (e^β= 0.82, 95% CI: 0.71, 0.93). Baseline VO_2max was inversely associated with relative PA adherence (e^β=0.98, 95% CI=0.95, 0.99). No other baseline measures were associated with PA adherence.

CONCLUSIONS

There were no significant changes in absolute PA time ≥40% of HRR across time or between groups. However, the lower intensity PA group averaged over 3 times the relative amount of PA within the prescribed HRR zone compared to the higher intensity PA group. Finally, lower peer support and cardiorespiratory fitness at baseline were associated with higher PA adherence.

IMPLICATIONS FOR CANCER SURVIVORS

The recent rise in popularity of commercially available activity trackers provides new opportunities to promote PA participation remotely, and these devices can be used to continuously and objectively measure PA levels as an indicator of intervention adherence. Future studies are needed to explore baseline predictors, facilitators, and barriers to sustained activity tracker use to promote PA behavior change and intervention adherence in cancer survivors.

TRIAL REGISTRATION

This study was registered at www.clinicaltrials.gov (No. NCT03564899) on June 21, 2018.

Estimation of maximal oxygen uptake from the 3,000 m run in adult men and women

The 3,000 m run is a frequently used field test for evaluating aerobic fitness. The test has previously been validated using smaller sample sizes and with focus restricted to the correlation between run performance and maximal oxygen uptake (V̇O_2max). The aim of the present study was to generate equations for converting 3,000 m performance into predicted V̇O_2max , and present corresponding validity statistics. In total 259 (30 female) military cadets and recruits (18-39 years) participated in the study. The subjects carried out a 3,000 m run and a direct treadmill V̇O_2max test. The Pearson r between V̇O_2max and average 3,000 m run speed were 0.74 and 0.79 in men and women, respectively. Two V̇O_2max prediction equations were generated: (1) Men: Ŷ = 17.5 + 2.57X and (2) Women: Ŷ = 14.6 + 2.48X (X = 3,000 m average run speed in km·h^-1). The equations produced a standard error of estimate of 3.3 and 2.6 mL·kg^-1·min^-1, and limits of agreement of 6.4 and 5.0 mL·kg^-1·min^-1 in men and women, respectively. The validity of the 3,000 m test is comparable to other indirect maximal running tests and is a time-effective alternative aerobic fitness test in healthy and motivated subjects.

Reliability of corticospinal excitability estimates for the vastus lateralis: Practical considerations for lower limb TMS task selection

Transcranial magnetic stimulation (TMS) is increasingly used to examine lower extremity corticospinal excitability (CSE) in clinical and sports research. Because CSE is task-specific, there is growing emphasis on the use of ecological tasks. Nevertheless, the comparative reliability of CSE measurements during established (e.g. knee extensions; KE) and more recent ecological (e.g. squats; SQT) lower extremity tasks has received less attention. The aim of this study was to compare the test-retest reliability of CSE, force, and muscle activity (EMG) during isometric SQT and KE. 19 right-footed men (age: 25 ± 5 yrs) with similar fitness and body composition performed SQT (N = 7) or KE (N = 12) on two consecutive days. Force and EMG were recorded during maximum voluntary isometric contractions (MVC). Corticospinal excitability was determined in the dominant leg during light (15% MVC) contractions based on motor evoked potential (MEP) stimulus-response-curves (SRC). Test-retest reliability, absolute agreement, and consistency were determined for force, EMG, and SRC MEP maximum (MEPMAX) and rising phase midpoint (V50). As a secondary analysis, all outcomes were compared between groups with mixed-methods ANCOVAs (Task × Time, covariate: body-fat-percentage). Compared with SQT, KE displayed better test-retest reliability and agreement for MEPMAX whereas V50, force, and EMG were similarly reliable. Force (p = 0.01) and MEPMAX (p = 0.02) were also greater during KE despite a similar V50 (p = 0.11). Differences in test-retest reliability, absolute agreement, and between-group comparisons highlight the need to carefully select lower limb TMS assessment tasks and encourage future efforts to balance ecological validity with statistical sensitivity.

Accuracy of Exercise-based Equations for Estimating Cardiorespiratory Fitness

Equations are often used to predict cardiorespiratory fitness (CRF) from submaximal or maximal exercise tests. However, no study has comprehensively compared these exercise-based equations with directly measured CRF using data from a single, large cohort.

PURPOSE

This study aimed to compare the accuracy of exercise-based prediction equations with directly measured CRF and evaluate their ability to classify an individual's CRF.

METHODS

The sample included 4871 tests from apparently healthy adults (38% female, age 44.4 ± 12.3 yr (mean ± SD)). Estimated CRF (eCRF) was determined from 2 nonexercise equations, 3 submaximal exercise equations, and 10 maximal exercise equations; all eCRF calculations were then compared with directly measured CRF, determined from a cardiopulmonary exercise test. Analysis included Pearson product-moment correlations, standard error of estimate values, intraclass correlation coefficients, Cohen κ coefficients, and the Benjamini-Hochberg procedure to compare eCRF with directly measured CRF.

RESULTS

All eCRF values from the prediction equations were associated with directly measured CRF (P < 0.01), with intraclass correlation coefficient estimates ranging from 0.07 to 0.89. Although significant agreement was found when using eCRF to categorize participants into fitness tertiles, submaximal exercise equations correctly classified an average of only 51% (range, 37%-58%) and maximal exercise equations correctly classified an average of only 59% (range, 43%-76%).

CONCLUSIONS

Despite significant associations between exercise-based prediction equations and directly measured CRF, the equations had a low degree of accuracy in categorizing participants into fitness tertiles, a key requirement when stratifying risk within a clinical setting. The present analysis highlights the limited accuracy of exercise-based determinations of eCRF and suggests the need to include cardiopulmonary measures with maximal exercise to accurately assess CRF within a clinical setting.

Effect of High-Intensity Interval Training Versus Moderate-Intensity Aerobic Continuous Training on Galectin-3 Gene Expression in Postmenopausal Women: A Randomized Controlled Trial

Galectin-3 is a pro-inflammatory biomarker associated with the pathogenesis of heart failure (HF). Physical-activity reduces the risk of heart-failure by modification of inflammation and fibrosis. The purpose of this study was to compare the effects of 8 weeks of high-intensity interval training (HIIT) versus moderate-intensity aerobic continuous training on a predictive factor of HF in postmenopausal women. Thirty sedentary postmenopausal women were randomly assigned to three groups. The first group performed the HIIT program at 60%-90%, and the second group performed an exercise program at 50%-65% of HR reserve. The control group maintained their normal daily regular physical activity level. The gene expressions of galectin-3 and lipid profiles were measured at the baseline and the end of Week 8. The HIIT and moderate-intensity aerobic continuous training attenuated the gene expression of galectin-3, serum low-density lipoprotein, cholesterol, and triglyceride concentrations and enhanced high-density lipoprotein concentrations. These changes were considerably higher in the HIIT group. Our results show that HIIT is superior to moderate-intensity aerobic continuous training in improving the decrease in HF risk in postmenopausal women.

Association of Baseline and Longitudinal Changes in Body Composition Measures With Risk of Heart Failure and Myocardial Infarction in Type 2 Diabetes: Findings From the Look AHEAD Trial

BACKGROUND

Intentional weight loss is associated with lower risk of heart failure (HF) and atherosclerotic cardiovascular disease among patients with type 2 diabetes. However, the contribution of baseline measures and longitudinal changes in fat mass (FM), lean mass (LM), and waist circumference (WC) to the risk of HF and myocardial infarction (MI) in type 2 diabetes is not well established.

METHODS

Adults from the Look AHEAD trial (Action for Health in Diabetes) without prevalent HF were included. FM and LM were predicted using validated equations and compared with dual-energy x-ray absorptiometry measurements in a subgroup. Adjusted Cox models were used to evaluate the associations of baseline and longitudinal changes in FM, LM, and WC over 1- and 4-year follow-up with risk of overall HF, HF with preserved ejection fraction (EF; EF ≥50%), HF with reduced EF (EF <50%), and MI.

RESULTS

Among 5103 participants, there were 257 incident HF events over 12.4 years of follow-up. Predicted and measured FM/LM were highly correlated (R²=0.87-0.90; n=1369). FM and LM decreased over 4-year follow-up with greater declines in the intensive lifestyle intervention arm. In adjusted analysis, baseline body composition measures were not significantly associated with HF risk. Decline in FM and WC, but not LM, over 1 year were each significantly associated with lower risk of overall HF (adjusted hazard ratio per 10% decrease in FM, 0.80 [95% CI, 0.68-0.95]; adjusted hazard ratio per 10% decrease in WC, 0.77 [95% CI, 0.62-0.95]). Decline in FM was significantly associated with lower risk of both HF subtypes. In contrast, decline in WC was significantly associated with lower risk of HF with preserved EF but not HF with reduced EF. Similar patterns of association were observed for 4-year changes in body composition and HF risk. Longitudinal changes in body composition were not significantly associated with risk of MI.

CONCLUSIONS

In adults with type 2 diabetes, a lifestyle intervention is associated with significant loss of FM and LM. Declines in FM and WC, but not LM, were each significantly associated with lower risk of HF but not MI. Furthermore, decline in WC was significantly associated with lower risk of HF with preserved EF but not HF with reduced EF. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00017953.

Effects of yoga, aerobic, and stretching and toning exercises on cognition in adult cancer survivors: protocol of the STAY Fit pilot randomized controlled trial

Background

Cancer survivors experience compromised quality of life due to impaired cognitive function as a result of cancer diagnosis and treatment. Although exercise has proven to be effective in improving cognitive function across the lifespan, interventions comprehensively testing the effectiveness for cancer survivors are limited. The STAY Fit Trial is a three-armed pilot randomized controlled trial designed to compare the effects of a 12-week yoga, aerobic walking, and stretch and tone intervention on cognitive function among adult cancer survivors.

Methods

This pilot study aims to recruit 75 adult cancer survivors who will complete assessments of cognitive function, cardiovascular fitness, physical activity, and psychosocial measures at baseline and after the 12-week intervention. The aims of STAY Fit are (1) to assess the efficacy of yoga to improve cognitive function among cancer survivors, compared to aerobic exercise and an active control group; (2) to examine changes in cardiovascular fitness as a result of the interventions; and (3) to assess changes in quality of life among our population as a result of the exercise interventions.

Discussion

The STAY Fit Trial will test the effectiveness of yoga, aerobic exercise, and stretching and toning exercises in improving cognitive function and fitness among adult cancer survivors. The results of this pilot study will enable us to understand the most effective physical activity modality to improve cognitive function in this population and potentially combat cancer-related cognitive impairment.

Trial registration

ClinicalTrials.gov NCT03650322. Registered on 28 August 2018.

Maintenance of Fitness and Quality-of-Life Benefits From Supervised Exercise Offered as Supportive Care for Breast Cancer

BACKGROUND

Overwhelming randomized controlled trial evidence demonstrates that exercise has positive health impacts during and after treatment for breast cancer. Yet, evidence generated by studies in which exercise programs are delivered outside a tightly controlled randomized trial setting is limited. The purpose of this study was to assess the effectiveness of an evidence-based exercise program with real-world implementation on physical fitness and quality of life (QoL).

PATIENTS AND METHODS

Oncologists referred women with early-stage breast cancer who were scheduled to receive adjuvant chemotherapy. The program consisted of supervised aerobic and resistance exercise of moderate to vigorous intensity 3 times per week until the end of treatment (chemotherapy ± radiotherapy), then twice per week for 10 weeks, followed by once per week for 10 weeks. Health-related physical fitness and QoL were assessed at baseline, end of treatment, end of program, and 1-year follow-up.

RESULTS

A total of 73 women were enrolled. Estimated peak VO2 (VO2peak), QoL, and body weight were maintained between baseline and end of treatment, whereas muscular strength improved (P<.01). By the end of the program, VO2peak, heart rate recovery, waist circumference, and some aspects of QoL were improved (all P<.01) relative to baseline. One year later, VO2peak, QoL, and waist circumference were maintained relative to end of program, whereas the improvements in strength and heart rate recovery had dissipated (all P<.01).

CONCLUSIONS

Evidence-based exercise programming delivered with real-world implementation maintained VO2peak, strength, and QoL during adjuvant treatment and improved these measures after treatment completion among women with breast cancer. Continued guidance and support may be required for long-term maintenance of strength improvements in this population.

Predictors of Adherence to Different Volumes of Exercise in the Breast Cancer and Exercise Trial in Alberta

BACKGROUND

Exercise demonstrates a dose-response effect on many health outcomes; however, adhering to higher doses of exercise can be challenging, and the predictors of adherence may differ based on exercise volume.

PURPOSE

To examine the predictors of adherence to two different volumes of aerobic exercise within the Breast Cancer and Exercise Trial in Alberta (BETA).

METHODS

In BETA, we randomized 400 inactive but healthy postmenopausal women to either a moderate volume (150 min/week) or a high volume (300 min/week) of aerobic exercise for 1 year. We collected data on several predictors of exercise adherence at baseline and used linear and mixed-effect models to determine predictors of exercise adherence to exercise volume and overall.

RESULTS

Adherence was higher in the moderate-volume group (84.5%) compared with the high-volume group (75.2%; p < .001). There were no statistically significant interactions between predictors of exercise adherence and exercise volume. Overall, we found that exercise adherence was predicted by randomization group, body mass index (BMI), employment status, and physical health. Adherence was 8.6% lower in the high-volume versus moderate-volume group, 6.7% lower for women working full time versus not, 0.8% lower per BMI increase of 1 kg/m2, and 0.5% higher per unit of physical health.

CONCLUSIONS

Adherence to high-volume aerobic exercise was more challenging than for moderate-volume aerobic exercise, but the predictors of adherence were similar. Moreover, few factors were major predictors of exercise adherence in this setting suggesting that well-controlled efficacy trials that produce high adherence rates may reduce the influence of individual characteristics on exercise adherence.

TRIAL REGISTRATION

NCT1435005.

Functional Movement Screening Performance and Association With Key Health Markers in Older Adults

Farrell, SW, Pavlovic, A, Barlow, CE, Leonard, D, DeFina, JR, Willis, BL, DeFina, LF, and Haskell, WL. Functional movement screening performance and association with key health markers in older adults. J Strength Cond Res XX(X): 000-000, 2019-We examined Functional Movement Screening (FMS) performance and associations with key health markers among adults aged 55 years or older. Apparently healthy men (n = 425) and women (n = 158) completed a preventive medical examination between 2013 and 2018. Subjects were grouped by age and sex to determine mean scores for individual FMS items as well as total FMS score. We examined partial correlations between total FMS score and key health markers. We computed odds ratios (ORs) for having a total FMS score ≤14. The mean FMS scores for men and women were 11.7 ± 2.8 and 11.9 ± 2.3, respectively. Several differences were found between men who participated in FMS (takers) compared with FMS nontakers, whereas women FMS takers were generally similar to women FMS nontakers. After controlling for age, sex, and smoking, FMS scores were directly associated with physical activity (PA), cardiorespiratory fitness, frequency of resistance training, serum vitamin D, omega-3 index, low-density lipoprotein, and high-density lipoprotein (HDL)-cholesterol, and were inversely associated with body mass index (BMI), waist circumference (WC), blood glucose, HbA1c, and metabolic syndrome (p ≤ 0.02 for each). Adjusted OR for scoring ≤14 was significantly greater for those who were BMI and WC-obese, those with metabolic syndrome, those with low HDL-cholesterol, and those not meeting current PA guidelines. This study provides characteristics and mean values for FMS in a large older population and demonstrates that FMS performance is associated with key health markers. Prospective studies of older adults are needed to determine the utility of FMS in predicting future musculoskeletal injury and other chronic disease-related health outcomes.

The Effect of Glutamine Supplementation on Oxidative Stress and Matrix Metalloproteinase 2 and 9 After Exhaustive Exercise

Background

Glutamine is the most abundant amino acid in plasma and skeletal muscles and an important fuel for immune system cells. It has beneficial anti-inflammatory and antioxidant properties which may be considered as a potentially useful supplement for athletes. The present study was conducted to investigate the effect of glutamine supplementation on oxidative stress and matrix metalloproteinase 2 and 9 after exhaustive exercise in young healthy males.

Materials and methods

In this study, 30 healthy males (supplement =15 and control=15) were randomly assigned into two groups. The supplement group received 0.3 g/kg BW of glutamine along with 25 gr of sugar dissolved in 250 cc water per day. The control group received 25 gr of sugar in 250 cc water per day. Fasting blood samples were taken at baseline and at the end of 14 days of intervention. The participants underwent exercise until experiencing full-body exhaustive fatigue for 16 ± 2.84 mins, and then fasting blood samples were taken. Serum levels of TAC, MDA, MMP2, MMP9, glutathione, and hs-CRP were measured.

Results

Serum levels of MDA and hs-CRP significantly decreased in the supplement group (p< 0.05). The serum level of TAC significantly increased in the supplement group (p< 0.05). Glutathione serum levels significantly increased after exhaustive exercise (p< 0.05). Serum levels of MMP2 and MMP9 remained unchanged.

Conclusion

Results of this study showed that, some biochemical factors are time-dependent and can increase or decrease over time, as well as, serum levels of hs-CRP and MDA decreased with glutamine supplementation along with the increase in the TAC serum levels, but this supplementation had no effect on serum levels of MMP2 and MMP9 in exhaustive exercise.

The association between cardiorespiratory fitness and the incidence of common mental health disorders: A systematic review and meta-analysis

BACKGROUND

Physical activity is associated with a lower incidence of common mental health disorder, but less is known about the impact of cardiorespiratory fitness (CRF).

METHODS

In this review, we systematically evaluated the relationship between CRF and the incidence of common mental health disorders in prospective cohort studies. We systematically searched six major electronic databases from inception to 23rd of May 2019. We assessed study quality using the Newcastle-Ottawa scale.

RESULTS

We were able to pool the hazard ratios (HRs) and 95% confidence intervals (CIs) of four studies including at least 27,733,154 person-years of data. We found that low CRF (HR = 1.47, [95% CI 1.23 - 1.76] p < 0.001 I2 = 85.1) and medium CRF (HR = 1.23, [95% CI 1.09 - 1.38] p < 0.001 I2 = 87.20) CRF are associated with a 47% and 23% greater risk of a common mental health disorders respectively, compared with high CRF. We found evidence to suggest a dose-response relationship between CRF and the risk of common mental health disorders.

LIMITATIONS

We were only able to identify a small number of eligible studies from our search and heterogeneity was substantial in the subsequent meta-analysis.

CONCLUSIONS

Our findings indicate that there is a longitudinal association between CRF levels and the risk of a common mental health disorder. CRF levels could be useful for identifying and preventing common mental health disorders at a population-level.