Effect of BMI, Body Fat Percentage and Fat Free Mass on Maximal Oxygen Consumption in Healthy Young Adults

Assessment of Physical Fitness Following a 12-Week Physical Exercise Program Among Adults Attending Wellness Centers at the Primary Health Care Corporation, Qatar: A Retrospective Study

Background Physical fitness (PF) is a critical determinant of health, influencing cardiorespiratory endurance, muscular strength, and overall metabolic function. In Qatar, sedentary lifestyles and physical inactivity are prevalent, contributing to increasing rates of obesity and non-communicable diseases. Structured physical exercise programs, integrated into community wellness centers, offer a practical intervention to improve PF, yet their real-world effectiveness remains under-evaluated in the local context. Methods This retrospective study analyzed data from 739 adults who completed a 12-week structured physical exercise program at seven wellness centers operated by Primary Health Care Corporation (PHCC), Qatar, between January 2022 and December 2023. The program consisted of three weekly supervised sessions combining aerobic and resistance exercises, with heart rate monitored to maintain moderate intensity (≥70% of maximum heart rate). Pre- and post-program assessments measured VO2 max (using the Cooper 12-minute test), muscular endurance (push-ups, wall sit, plank), and anthropometric data of weight, body mass index (BMI), waist circumference (WC), and fat mass. Paired t-tests assessed changes in the means before and after the physical exercise program, and correlation analysis explored relationships between fitness improvements and demographic or anthropometric factors. Results After 12 weeks, VO2 max increased significantly (mean difference = 2.47 mL/kg/min; p < 0.001), alongside improvements in muscular endurance (push-ups: +4 reps; wall sit: +18 seconds; plank: +16.77 seconds; all p < 0.001). Significant reductions were observed in weight (-0.95 kg), BMI (-0.27 kg/m²), WC (men: -0.99 cm; women: -2.34 cm), and fat mass (-1.42 kg) (p < 0.001). Correlation analysis revealed a weak negative correlation between age and VO2 max change (r = 0.061), indicating that younger participants tended to show more remarkable aerobic improvement. Higher BMI and fat mass also correlated negatively with VO2 max gains (r = -0.094 and r = -0.083, respectively). At the same time, gender showed minimal correlation with fitness changes, suggesting that baseline body composition and age influence exercise response more than sex. Conclusion The structured 12-week exercise program significantly improved PF among adults in community wellness settings. These findings support integrating exercise prescriptions into primary care, to enhance population-level fitness and prevent chronic disease in Qatar.

Cardiopulmonary Exercise Testing

AbstractBecause symptoms of cardiopulmonary disease often occur with exertion, cardiopulmonary exercise testing (CPET) has a unique role in the assessment of patient symptoms, disease severity, prognosis, and response to therapy. In addition to the evaluation of cardiovascular and pulmonary physiology, CPET provides an assessment of the interaction of the cardiovascular and pulmonary systems with the musculoskeletal, nervous, and hematological systems. In this article, we review key CPET variables, protocols, and clinical indications.

Impact of Body Mass Index and VO2 Max on Symptoms, Physical Activity, and Physical Function in a Multinational Sample of People with HIV

People with HIV (PWH) are at increased risk for metabolic disorders affecting body mass index (BMI), chronic symptoms, and impaired physical function and capacity. Although physical activity improves health and well-being, PWH often do not meet activity recommendations necessary to achieve these benefits. Despite the known impact of symptoms, physical activity, and physical function on health, little is known about the relationships and interactions between these variables and BMI and maximum oxygen consumption during exercise (VO2 max) in a multinational population of PWH. We examined the relationship of BMI with PROMIS-29 measures, physical activity, strength, flexibility, and VO2 max in a diverse sample of PWH. Additionally, we examined the relationship of VO2 max with PROMIS-29 measures. Data from 810 PWH who participated in a cross-sectional study conducted by the International Nursing Network for HIV Research (Study VII) were analyzed. Participants were recruited from 8 sites across the United States, Thailand, and South Africa. BMI was calculated from collected height and weight data. Physical function and symptoms were assessed using the PROMIS-29 measure. Physical activity was assessed using the 7-day Physical Activity Recall. VO2 max was calculated using sex at birth, age, BMI and the 6-minute Walk Test. Data were analyzed using descriptive, correlational, and regression statistical analyses. Participants had an average age of 49.1 (± 11.1) years, 44% were female, and the average BMI of the sample group was 27 kg/m2 (± 6.7). Increased BMI was associated with decreased 6-minute Walk Test (β=-2.18, p < 0.001), flexibility (β=-0.279, p < 0.001), and VO2 max (β=-0.598, p < 0.001), even after controlling for covariates (age, sex at birth, country, years living with HIV, and antiretroviral therapy status). BMI was not associated with self-reported physical activity. Increased VO2 max was associated with increased physical function (β = 0.069, p < 0.001), and decreased pain (β=-0.047, p < 0.006), even after controlling for covariates (country, years living with HIV, and antiretroviral therapy status). Future research should explore development of effective and sustainable symptom self-management interventions in PWH accounting for the potential impact of BMI and VO2 max.

Study on heart rate recovery index to predict maximum oxygen uptake in healthy adults aged 30 to 60 years old

Objective

To explore the feasibility of post-exercise heart rate recovery indicators for predicting maximum oxygen uptake (VO2max) in healthy adults aged 30-60 years.

Methods

260 healthy adults who did not perform regular exercise were randomly recruited and divided into a model group (n = 200) and a verification group (n = 60). Measure body fat percentage, weight, height and other indicators, and complete a cardiopulmonary exercise test as required to measure VO2max and heart rate recovery (HRR1, HRR2) in the first and second minutes after exercise. Equations are established through stepwise regression method, and the selected optimal equation is tested for back substitution.

Results

The optimal equation is: Absolute VO 2 ⁡ max = - 0.528 + 0.039 * weight - 3.463 * body fat rate + 0.042 * HRR 2 - 0.180 * gender  male = 1 , female = 2 . Analysis of variance, goodness-of-fit test, VIF test, Shapiro-Wilk test, and Durbin-Watson test indicate that the equation is more reliable; Pearson product-moment correlation analysis, paired t test, and Bland-Altman consistency test indicate that the equation is more valid good.

Conclusion

The regression equation established through heart rate recovery after exercise can be used to predict VO2max in healthy adults aged 30-60 years.

Enhancing Heart Rate-Based Estimation of Energy Expenditure and Exercise Intensity in Patients Post Stroke

BACKGROUND

Indirect calorimetry is the gold standard field-testing technique for measuring energy expenditure and exercise intensity based on the volume of oxygen consumed (VO2, mL O2/min). Although heart rate is often used as a proxy for VO2, heart rate-based estimates of VO2 may be inaccurate after stroke due to changes in the heart rate-VO2 relationship. Our objective was to evaluate in people post stroke the accuracy of using heart rate to estimate relative walking VO2 (wVO2) and classify exercise intensity. Moreover, we sought to determine if estimation accuracy could be improved by including clinical variables related to patients' function and health in the estimation.

METHODS

Sixteen individuals post stroke completed treadmill walking exercises with concurrent indirect calorimetry and heart rate monitoring. Using 70% of the data, forward selection regression with repeated k-fold cross-validation was used to build wVO2 estimation equations that use heart rate alone and together with clinical variables available at the point-of-care (i.e., BMI, age, sex, and comfortable walking speed). The remaining 30% of the data were used to evaluate accuracy by comparing (1) the estimated and actual wVO2 measurements and (2) the exercise intensity classifications based on metabolic equivalents (METs) calculated using the estimated and actual wVO2 measurements.

RESULTS

Heart rate-based wVO2 estimates were inaccurate (MAE = 3.11 mL O2/kg/min) and unreliable (ICC = 0.68). Incorporating BMI, age, and sex in the estimation resulted in improvements in accuracy (MAE Δ: -36.01%, MAE = 1.99 mL O2/kg/min) and reliability (ICC Δ: +20, ICC = 0.88). Improved exercise intensity classifications were also observed, with higher accuracy (Δ: +29.85%, from 0.67 to 0.87), kappa (Δ: +108.33%, from 0.36 to 0.75), sensitivity (Δ: +30.43%, from 0.46 to 0.60), and specificity (Δ: +17.95%, from 0.78 to 0.92).

CONCLUSIONS

In people post stroke, heart rate-based wVO2 estimations are inaccurate but can be substantially improved by incorporating clinical variables readily available at the point of care.

Selected somatic parameters and body composition as predictors of cardiorespiratory fitness among Polish adolescents aged 11-14

The aim of the study was to verify whether selected somatic parameters and components of body composition were significant predictors of cardiorespiratory fitness (CRF) among a potentially healthy Polish population of adolescents aged 11-14 years. The cross-sectional study was conducted on a group of 375 subjects (164 girls, and 211 boys). A 20 m shuttle run test (20 m SRT) was used to assess CRF. The total number of rounds was taken into account. Basic somatic parameters were measured: body mass (BM), body height (BH), waist circumference (WC), hip circumference (HC), body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR), and body composition components: body fat percentage (FM%), fat mass (FM kg), total body water (TBW), fat-free mass (FFM). Statistical analyses included basic statistical measures (mean and standard deviation) and Spearman rank correlation coefficient. Multiple linear regression analysis was performed to detect significant predictors of CRF. In each proposed model, the dependent variable was the number of rounds, and the independent variables were selected somatic parameters and components of body composition. More than half (65%) of the subjects had an average or lower level of CRF, and 35% of the population presented a good or above good level of CRF. The study showed a statistically significant negative correlation between BM, FM%, FM kg, HC, WC, BMI, WHR, WHtR and the number of laps in the total sample. The strongest correlation in the group of girls was noted for age (r = 0.34) and in the group of boys for FM% (r = - 0.52 ). Each regression model presented proved to be statistically significant, and the significant predictors of CRF in the group of girls were age ( R 2 = 16%) and FM% ( R 2 = 6%). In the group of boys, the significant predictors of CRF were WHtR ( R 2 = 8%) and age ( R 2 = 2%). Estimating body fat distribution is useful in assessing cardiorespiratory fitness, and this in turn indicates its usefulness in preventive screening of school-aged adolescents.

Reference values for estimated VO2max by two submaximal cycle tests: the Åstrand-test and the Ekblom-Bak test

AIMS

Submaximal tests estimating VO2max have inherent biases; hence, using VO2max estimations from the same test is essential for reducing this bias. This study aimed to establish sex- and age-specific reference values for estimated VO2max using the Åstrand-test (Å-test) and the Ekblom-Bak test (EB-test). We also assessed the effects of age, exercise level, and BMI on VO2max estimations.

METHODS

We included men and women (20-69 years) from the Swedish working population participating in Health Profile Assessments between 2010 and 2020. Excluding those on heart rate-affecting medicines and smokers, n = 263,374 for the Å-test and n = 95,043 for the EB-test were included. VO2max reference values were based on percentiles 10, 25, 40, 60, 75, and 90 for both sexes across 5-year age groups.

RESULTS

Estimated absolute and relative VO2max were for men 3.11 L/min and 36.9 mL/min/kg using the Å-test, and 3.58 L/min and 42.4 mL/min/kg using the EB-test. For women, estimated absolute and relative VO2max were 2.48 L/min and 36.6 mL/min/kg using the Å-test, and 2.41 L/min and 35.5 mL/min/kg using the EB-test. Higher age (negative), higher exercise level (positive), and higher BMI (negative) were associated with estimated VO2max using both tests. However, explained variance by exercise on estimated VO2max was low, 10% for the Å-test and 8% for the EB-test, and moderate for BMI, 23% and 29%.

CONCLUSION

We present reference values for estimated VO2max from two submaximal cycle tests. Age, exercise, and BMI influenced estimated VO2max. These references can be valuable in clinical evaluations using the same submaximal tests.

Effect of weight satisfaction on adolescent facial and dental satisfaction

PURPOSE

To investigate if facial and dental satisfaction is related to body fat percentage and body weight satisfaction.

METHODS

A self-administered questionnaire was applied to adolescents from a Private School in Southern Brazil containing sociodemographic (sex and age) and self-perception variables. Adolescents were asked about their perceptions concerning dental problems. Body fat percentage was collected using bioelectrical impedance analysis.

RESULTS

A total of 372 adolescents were examined. Most adolescents were satisfied with their dental (81.7%) and facial appearance (87.6%), while 39% of adolescents were satisfied with their body weight. Poisson regression model showed that adolescents who expressed satisfaction with their body weight (PR = 1.12, 95%CI 1.06-1.19) and were satisfied with their dental appearance (PR = 1.24, 95% CI 1.08-1.41) exhibited a positive association with facial satisfaction. Adolescents dissatisfied with dental color (PR = 0.88, 95%CI 0.80-0.97), those reporting dental pain (PR = 0.88, 95%CI 0.80-0.97), and individuals with obesity (PR = 0.91, 95%CI 0.83-0.99) demonstrated a decrease in facial satisfaction. Adolescents aged 16 to 19 years (PR = 1.08, 95% CI 1.01-1.15) and those satisfied with their facial appearance (PR = 1.20, 95%CI 1.01-1.43) exhibited a higher prevalence of dental satisfaction. Conversely, adolescents dissatisfied with dental color (PR = 0.74, 95% CI 0.66-0.82) and those with misaligned teeth (PR = 0.63, 95%CI 0.55-0.73) reported lower levels of dental satisfaction. Parametric g-formula analysis found that the association between body fat and facial satisfaction was mediated by body weight satisfaction (p = 0.001).

CONCLUSIONS

While dental satisfaction was not influenced by corporeal characteristics, facial satisfaction was influenced by dental and body weight satisfaction. Obese adolescents had low facial satisfaction.

Plant-based diets benefit aerobic performance and do not compromise strength/power performance: a systematic review and meta-analysis

Plant-based diets have emerged as athletic performance enhancers for various types of exercise. Therefore, the present study evaluated the effectiveness of plant-based diets on aerobic and strength/power performances, as well as on BMI of physically active individuals. This systematic review and meta-analysis was conducted and reported according to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. A systematic search of electronic databases, including PubMed, Web of Science and SPORTDiscus, was performed. On the basis of the search and inclusion criteria, four and six studies evaluating the effects of plant-based diets on aerobic and strength/power performances in humans were, respectively, included in the systematic review and meta-analysis. Plant-based diets had a moderate but positive effect on aerobic performance (0·55; 95 % CI 0·29, 0·81) and no effect on strength/power performance (-0·30; 95 % CI -0·67, 0·07). The altogether analyses of both aerobic and strength/power exercises revealed that athletic performance was unchanged (0·01; 95 % CI -0·21, 0·22) in athletes who adopted plant-based diets. However, a small negative effect on BMI (-0·27; 95 % CI -0·40, -0·15) was induced by these diets. The results indicate that plant-based diets have the potential to exclusively assist aerobic performance. On the other hand, these diets do not jeopardise strength/power performance. Overall, the predicted effects of plant-based diets on physical performance are impactless, even though the BMI of their adherents is reduced.

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.

The role of body composition on cardio-respiratory fitness in futsal competitive athletes

Futsal is an intermittent high intensity sport which has become popular worldwide. Body composition and physical fitness have been studied in different sports disciplines. However, little is known regarding body composition and cardio-respiratory performance in competitive futsal players. Body composition parameters were analyzed by electrical impedance body composition analyzer in 31 competitive male futsal players. All participants performed spirometry, handgrip strength and cardiopulmonary exercise testing. Significant correlations were observed between muscle mass and spirometry parameters and peak VO2 (p≤0.05). Fat mass resulted inversely correlated with peak VO2% predicted and hand grip strength (p≤0.05). Regression analysis showed that muscle mass significantly predicts respiratory parameters (p<0.01) and reduced fat mass is associated with increased peak VO2 % predicted and handgrip strength (p<0.01). In futsal competitive athletes increased muscle mass is associated with higher spirometry parameters and fat mass is inversely associated with lower cardiorespiratory fitness.

Comparison of Cardiovascular Response to Lower Body and Whole Body Exercise Among Sedentary Young Adults

Background Cardiovascular responses to exercise are essential indicators of cardiovascular health and fitness. Understanding how different types of exercise, such as lower-body and whole-body exercises, impact these responses is crucial for designing effective fitness programs and assessing cardiovascular function. Aim This study aimed to compare the cardiovascular response of young adults during lower-body exercise using a bicycle ergometer and whole-body exercise on a treadmill. Methods Thirty-two healthy young adults participated in this study. Each participant completed two exercise sessions on separate days: lower-body exercise on a bicycle ergometer with a fixed cadence of 60 rpm with a breaking resistance of 1.75 kg and whole-body exercise on a treadmill with a speed of 1.7 mph and a 10% grade. Heart rate (HR), systolic blood pressure (BP), and diastolic BP were measured at rest and immediately after a three-minute exercise. Data were analyzed using paired t-tests to compare the cardiovascular responses between the two exercise modalities. Results A total of 17 male and 15 female young adults with a mean age of 20.87±1.43 years participated in the study. The male and female participants had similar ages (p =0.56) and body mass indexes (p = 0.1). There was a higher HR (129.16±2.67 versus 150.87±3.23, p<0.0001) and systolic BP (127.29±2.34 versus 144.9±4.16, p<0.0001) and lower diastolic BP (68.97±2.41 versus 62.97±2.31, p<0.0001) in whole body exercise on treadmill compared to lower body exercise in bicycle ergometer. The effect size was large enough as Cohen's d was 7.33, 5.13, and 2.54 for HR, systolic BP, and diastolic BP, respectively. Conclusion In sedentary young adults, treadmill exercise led to higher HR, systolic BP, and lower diastolic BP than bicycle ergometer exercise. Increased muscle recruitment might result in higher energy expenditure, increasing the HR and systolic BP to deliver oxygen and nutrients to the working muscles. Further research is needed to understand the mechanisms and long-term implications for precise exercise recommendations and better cardiovascular health management.

Feasibility of Conducting Sit-to-Stand Tests Using Video Consultation

Objective

This study is aimed at ascertaining the feasibility of conducting the 1-minute sit-to-stand (1MSTS) and 30-second sit-to-stand (30SSTS) tests for healthy participants via video consultation. A secondary aim was to compare the relationship between the 1MSTS and 30SSTS.

Methods

A total of 63 participants were recruited via the Singapore Institute of Technology emails and social media in 2020 during the peak of COVID-19. Prior to the sit-to-stand testing, all participants completed the consent form and physical activity questionnaires. Anthropometric data such as height and weight were also collected prior to testing. An instructional video detailing the sit-to-stand (STS) movement and the requirements for the environment set-up were sent to the participants via email. All STS tests were conducted virtually via the Zoom application. Healthy participants aged 21 to 55 years old performed a 1MSTS and 30SSTS each in random order.

Results

All recruited participants completed the STS tests with no reported adverse events. Majority of participants were from the 21- to 25-year-old age groups, and the average number of repetitions performed by this group was 21.9 ± 5.6 for the 30SSTS and 44.7 ± 12.6 for the 1MSTS.

Conclusion

Conducting the STS tests via video consultation was demonstrated to be safe and feasible. The number of repetitions performed in the 1MSTS is correlated to that of the 30SSTS, but 1MSTS has the ability to elicit a greater HR response among younger adults.

Is there an association between total physical activity level and VO2max among fitness club members? A cross-sectional study

Background

Since cardiorespiratory fitness is an important predictor for all-cause mortality, it is of interest to know if meeting the physical activity (PA) recommendations is associated with higher levels of maximal oxygen uptake (VO_2max). We aimed to investigate the association between total PA level given as counts per minute (cpm) and minutes in moderate-to-vigorous PA (MVPA), and VO_2max in new fitness club members.

Methods

A total of 62 men and 63 women (≥ 18 years), defined as healthy (no disease considered to hinder PA) participated in this study. VO_2max (mL kg⁻¹ min⁻¹) was measured with a cardiopulmonary exercise (modified Balke protocol), and total PA level was measured with ActiGraph GT1M for seven consecutive days. All participants accumulating ≥ 10 h of activity recordings ≥ 4 days were included in the data analysis. To examine associations between PA level and VO_2max, a Pearson correlation and a multiple linear regression analysis adjusted for covariates were used.

Results

VO_2max (mL kg⁻¹ min⁻¹) was 40.5 ± 7.2 in men and 35.1 ± 6.0 in women. Total PA level (cpm) and MVPA (min) were 352.4 ± 123.4 and 260.0 ± 132.6 in men and 361.4 ± 103.8 and 273.2 ± 137.0 in women. Total PA level (men: r = 0.346, p < 0.01, women: r = 0.267 p < 0.01) and MVPA (men: r = 0.359, p =  < 0.01, women: r = 0.236, p = 0.03) was associated with VO_2max. When adjusting for age and body fat percentage, total PA level and MVPA were no longer associated with VO_2max (men: p = 0.11 and p = 0.79, women: p = 0.40 and p = 0.61). In men, age (β = − 0.469 p < 0.01) and body fat percentage (β = − 0.483, p < 0.01) were the strongest predictor for VO_2max. For women, body fat percentage was the strongest predictor for VO_2max (β = − 0.483, p < 0.01).

Conclusions

Total PA level and MVPA were associated with VO_2max, but the association was low and diminished when adjusted for age and body fat percentage. Body fat percentage (men and women) and age (men) were more strongly associated with VO_2max than total PA level and MVPA.

Heart rate recovery as an assessment of cardiorespiratory fitness in young adults

Background

Cardiorespiratory fitness, typically measured as peak oxygen uptake (VO2peak) during maximal graded exercise testing (GXTmax), is a predictor of morbidity, mortality, and cardiovascular disease. However, measuring VO2peak is costly and inconvenient and thus not widely used in clinical settings. Alternatively, postexercise heart rate recovery (HRRec), which is an index of vagal reactivation, is a valuable assessment of VO2peak in older adults and athletes. However, the validity of HRRec as a clinical indicator of cardiorespiratory fitness in young, sedentary adults, who are a rapidly growing population at risk for developing obesity and cardiovascular disease, has not been fully elucidated.

Methods

We investigated the association between cardiorespiratory fitness, measured by VO2peak (mL·kg-1·min-1), and HRRec measures after a GXTmax in 61 young (25.2 ± 6.1 years), sedentary adults (40 females) using 3 methods. We examined the relationship between VO2peak and absolute (b·min-1) and relative (%) HRRec measures at 1, 2, and 3 min post GXTmax, as well as a measure of the slow component HRRec (HRRec 1 min minus HRR 2 min), using Pearson's correlation analysis.

Results

VO2peak (36.5 ± 7.9 mL·kg-1·min-1) was not significantly correlated with absolute HRRec at 1 min (r = 0.18), 2 min (r = 0.04) or 3 min (r = 0.01). We also found no significant correlations between VO2peak and relative HRRec at 1 min (r = 0.09), 2 min (r = -0.06) or 3 min (r = -0.10). Lastly, we found no correlation between the measure of the slow component HRRec and VO2peak (r = -0.14).

Conclusions

Our results indicate that HRRec measures are not a valid indicator of cardiorespiratory fitness in young, sedentary adults.

Estimation of Functional Aerobic Capacity Using the Sit-to-Stand Test in Older Adults with Heart Failure with Preserved Ejection Fraction

Background: The 6-Min Walking Test (6MWT) has been proposed to assess functional aerobic capacity in patients with heart failure, but many older adults with heart failure cannot complete it. The adequacy of the 5-repetition Sit-To-Stand (5-STS), a simpler test than 6MWT, to assess the functional aerobic capacity in older adults with heart failure has not been evaluated. Objectives: This study aimed to assess the usefulness of 5-STS in estimating maximal oxygen uptake (VO2 peak) in older adults with heart failure with preserved ejection fraction (HFpEF). Methods: A cross-sectional study was carried out. Patients 70 years and older with HFpEF were included. A bivariant Pearson correlation and subsequent multivariate linear regression analysis were used to analyze the correlations between the 5-STS and the estimated VO2 peak. Results: Seventy-six patients (80.74 (5.89) years) were recruited. The 5-STS showed a moderate and inversely correlation with the estimated VO2 peak (r = −0.555, p < 0.001). The 5-STS explained 40.4% of the variance in the estimated VO2 peak, adjusted by age, sex, and BMI. When older adults were stratified by BMI, the 5-STS explained 70% and 31.4% of the variance in the estimated VO2 peak in older adults with normal weight and overweight/obesity, respectively. Conclusions: The 5-STS may be an easy tool to assess functional aerobic capacity in older adults with HFpEF, especially for those with normal weight.

Peak oxygen uptake in sportsmen with spinal cord injury: importance of body composition

BACKGROUND

Although peak oxygen uptake (VO<inf>2peak</inf>) is considered the most useful index of functional capacity, it's difficult to interpret the results of cardiopulmonary exercise testing (CPET) in individuals with spinal cord injury (SCI). In fact, VO<inf>2peak</inf> is usually normalized for total body weight, but body composition in persons with SCI largely varies depending on physical activity and time since injury, with a progressive loss of fat-free mass (FFM). This can lead to a misinterpretation of the cardiopulmonary fitness in this population.

AIM

Our study proposes a methodology of evaluation, based on bioelectrical impedance analysis (BIA), which could provide more individualized and accurate data in sportsmen with SCI.

DESIGN

Case-control study.

POPULATION

Ambulatory patients at the Sports Medicine Unit of the IRCCS A. Gemelli University Polyclinic Foundation, Rome, Italy.

METHODS

Comparison of data derived from BIA, echocardiography and CPET between 10 male sportsmen with complete, high SCI (group T) and 10 able-bodied controls (group C).

RESULTS

Mean VO<inf>2peak</inf>, weight-normalized VO<inf>2peak</inf>, fat-free mass (FFM)-normalized VO<inf>2peak</inf> and body cellular mass (BCM)-normalized values were significantly lower in group T. At the same heart rate (on average the 55% of the maximal theoretical for age), mean of absolute VO<inf>2</inf>, weight-normalized VO<inf>2</inf> and FFM-normalized VO<inf>2</inf> were still significantly lower in group T. Considering the BCM-normalized VO<inf>2</inf>, the group T showed greater values than controls, 39.4±7.8 vs. 31.1±8.5 mL/kg/min.

CONCLUSIONS

Body composition is a crucial factor for properly interpreting a CPET in individuals with SCI. In particular, normalization of VO<inf>2peak</inf> values for the BCM seems the most reliable tool to assess the real functional capacity in this population.

CLINICAL REHABILITATION IMPACT

A more accurate definition of the aerobic power and functional capacity of people with SCI can improve the monitoring of rehabilitations protocols and physical exercise in this population.

Physiological and Somatic Principal Components Determining VO2max in the Annual Training Cycle of Endurance Athletes

The purpose of the study was to assess the impact of training on the physiological variables achieved during the test effort in the macrocycle of road cyclists and their use in the maximal oxygen uptake (VO2max) prediction at individual training stages in the VO2max test. Nine well-trained male cyclists (age 25.6 ± 5.2 years and body weight 72.4 ± 7.35 kg) participated in the study and each phase of the macrocycle was followed by a time to exhaustion test (TTE) on the bicycle ergometer. The research showed that training loads significantly influence the maximum power (PPO), ventilation (VE) in the preparatory period (T1), time of the test (TTmax) at the start of the competition period (T2), percentage of body fat in total body weight (%FAT) and skeletal muscle mass (MMS) during the competition period (T3). Of the 16 variables taken for the analysis of the principal components (PC), the regression model determined one principal variable responsible for VO2max in the training macrocycle of cyclists, the relative value of maximum power (PPORV) and the accompanying variables in individual periods: breathing frequency (BF), delta blood lactate concentration (ΔLA), body fat (FAT) and MMS. Determining PC influencing the exercise capacity can be crucial in achieving the intended goals by athletes. Monitoring these indicators can help protect the health of professional athletes and provide guidelines in the training process, stimulate the body properly while protecting against overtraining.

Bioelectrical Impedance Vector Analysis Discriminates Aerobic Power in Futsal Players: The Role of Body Composition

Aims: The present study aimed to assess the ability of bioelectrical impedance vector analysis (BIVA) in discriminating fitness levels in futsal players, exploring the association of body composition and bioelectrical parameters with aerobic power. Methods: Forty-eight professional futsal players (age 23.8 ± 5.3 years) were involved in a cross-sectional study during their pre-season phase. Fat mass (FM) and muscle mass were determined by dual-energy X-ray absorptiometry. VO2max was obtained by indirect calorimetry through a graded exercise test performed on a treadmill. Bioelectrical resistance (R), reactance (Xc), and phase angle (PhA) were directly measured using a foot-to-hand bioimpedance technology at a 50 kHz frequency. Bioelectric R and Xc were standardized for the participants’ height and used to plot the bioimpedance vector in the R-Xc graph according to the BIVA approach. Results: The participants divided into groups of VO2max limited by tertiles showed significant differences in mean vector position in the R-Xc graph (p < 0.001), where a higher VO2max resulted in a longer vector and upper positioning. FM, muscle mass, and PhA differed (p < 0.01) among the athletes grouped by tertiles of VO2max, where athletes with a greater aerobic power showed a lower percentage of FM and a higher percentage of muscle mass and PhA. FM and PhA were associated with VO2max (FM: r = −0.658, p < 0.001; PhA: r = 0.493, p < 0.001). These relationships remained significant after adjusting for age and body mass (FM: ß = −0.335, p = 0.046; PhA: ß = 0.351, p = 0.003). Conclusions: Bioelectrical impedance vectors positioned on the lower pole of the R-Xc graph identified futsal players with a lower VO2max, while longer vectors corresponded to a greater aerobic power. Additionally, PhA, that describes the vector direction, was positively associated with VO2max, while a higher FM negatively affected VO2max in the futsal players. BIVA and PhA evaluation may represent a valid support for screening the aerobic fitness level in professional futsal players, when more sophisticated assessment methods are not available.

Effect of a Four-Week Vegan Diet on Performance, Training Efficiency and Blood Biochemical Indices in CrossFit-Trained Participants

This interventional study examined the effect of a four-week vegan diet (Veg_D) during a four-week high-intensity functional training (HIFT) on performance, training results and blood biochemical indices in female (n = 12) and male (n = 8) moderate-trained CrossFit participants. The whole study group performed the maximum number of repetitions with a load of 70% one repetition-maximum (1RM) and a modified Fight Gone Bad (FGB_Mod) test before and after a dietary intervention (the group was divided to follow a Veg_D or a traditional mixed diet (Mix_D)) in a randomised and parallel design. Pre-exercise resting blood samples were also analysed. There was a significant improvement in the number of repetitions performed at a load corresponding to 70% of 1RM in the classic squat in the Mix_D group (p < 0.001), and in the classic deadlift in the Veg_D group (p = 0.014). Furthermore, there was a significant improvement in the results of the FGB_Mod performance test after a Mix_D. Moreover, an improvement in some exercises in the modified FGB_Mod test (Wall Ball after the Veg_D and the Mix_D, and rowing after the Mix_D) was also observed. However, differences between the Mix_D and the Veg_D groups were not clinically relevant. In conclusion, the short-term study conducted here indicated that a Veg_D in HIFT training positively affects strength endurance in the classic deadlift but is unlikely to be more beneficial in improving performance than a Mix_D.

Differential Expression of Genes Associated with Chromatin Modifications in Skeletal Muscle during Aerobic Training Program

Introduction: Skeletal muscle plasticity in exercise can be modulated by epigenomic events such as gene silencing, histone modifications and DNA methylation. In this context, our objective was to analyze the expression of genes associated with chromatin modifications in human muscle biopsies of vastus lateralis after a 20 week training program. Methods: Using data from DNA microarray experiments registered in the NCBI GEO DataSet database GSE117070, we calculated the Z ratio values as the criterion to evaluate the differential expression of genes associated with chromatin modification during aerobic training in skeletal muscle. Using the web interface GENEMANIA, we built a co-expression interaction network with the overexpressed genes. We compared Z-score values obtained from pre-trained and post-trained samples through nonparametric tests. Results: We found 10 overexpressed genes after the 20 week training program, namely, EZH1, KMT2A, KMT2D, KDM4C, KDM6A, CREBBP, HDAC10, HDAC4, DNMT3L, and H2AX. The most relevant biological processes obtained from the network included chromatin organization (FDR 9.04×10-9) and histone modification (FDR 9.04×10-9). Conclusions: In skeletal muscle, after aerobic training, there is overexpression of genes associated with the modification of the chromatin through alterations in histones and DNA, resulting in epigenetic transcriptional changes.

Predictive equations to estimate peak aerobic capacity and peak heart rate in persons with Down syndrome

Estimations based on the available equations for predicting oxygen uptake (VO₂) from treadmill speed of locomotion are not appropriate for individuals with Down syndrome (DS). We aimed at developing prediction models for peak absolute oxygen uptake (VO_2peak) and peak heart rate (HR_peak) based on retrospective data from a healthy population with and without Down syndrome (DS). A cross-sectional analysis of VO_2peak and HR_peak was conducted in 196 and 187 persons with and without DS, respectively, aged from 16-45 years. Non-exercise data alone versus combined with HR_peak were used to develop equations predictive of absolute VO_2peak. Prediction equations for HR_peak were also developed. Two additional samples of participants (30 with, 29 without DS) enabled model cross-validation. Relative VO_2peak and HR_peak were lowest for persons with DS across all ages (~ 40% and 20 bpm, respectively). For persons with DS, VO_2peak predictions provided no differences compared with actual values. Predicted HR_peak was similar to actual values in both groups of participants. Large limits of agreement were obtained for VO_2peak (DS: 735, non-DS: 558.2 mL.min^-1) and HR_peak (DS: 24.8, non-DS: 16.6 bpm). Persons with DS exhibit low levels of VO_2peak and HR_peak in all age groups included in this study. It is possible to estimate absolute VO_2peak in persons with DS using non-exercise variables. HR_peak can be accurately estimated in groups of people with and without DS. Yet, because of large limits of agreement, caution is advised if using these equations for individual estimations of VO_2peak or HR_peak in either population.

Oxygen Saturation Behavior by Pulse Oximetry in Female Athletes: Breaking Myths

The myths surrounding women’s participation in sport have been reflected in respiratory physiology. This study aims to demonstrate that continuous monitoring of blood oxygen saturation during a maximal exercise test in female athletes is highly correlated with the determination of the second ventilatory threshold (VT2) or anaerobic threshold (AnT). The measurements were performed using a pulse oximeter during a maximum effort test on a treadmill on a population of 27 healthy female athletes. A common behavior of the oxygen saturation evolution during the incremental exercise test characterized by a decrease in saturation before the aerobic threshold (AeT) followed by a second significant drop was observed. Decreases in peripheral oxygen saturation during physical exertion have been related to the athlete’s physical fitness condition. However, this drop should not be a limiting factor in women’s physical performance. We found statistically significant correlations between the maximum oxygen uptake and the appearance of the ventilatory thresholds (VT1 and VT2), the desaturation time, the total test time, and between the desaturation time and the VT2. We observed a relationship between the desaturation time and the VT2 appearance. Indeed, a linear regression model between the desaturation time and the VT2 appearance can predict 80% of the values in our sample. Besides, we suggest that pulse oximetry is a simple, fairly accurate, and non-invasive technique for studying the physical condition of athletes who perform physical exertion.

Effect of Test Sequence on Maximal Anaerobic and Aerobic Power Achievements in Adults

The purpose of this study was to examine the effect of test sequence on adults' ability to achieve maximal aerobic and anaerobic power during a single assessment visit. Forty-one adults (24 men, 17 women; 22.0 ± 1.8 years) completed two baseline visits in randomized order consisting of either a maximal oxygen consumption (V̇O2max) or Wingate anaerobic test (WAnT). The subsequent experimental visit consisted of both V̇O2max and WAnT in randomized order separated by 20 minutes of rest. Mixed-model ANOVAs compared baseline and experimental performance between and within groups. Chi Squared Goodness of Fit tests determined if test sequence significantly affected V̇O2max criteria achievement. Significant interaction effects were observed for relative V̇O2max (p = 0.005), RER (p < 0.001), and exercise time (p = 0.022). Within WAnT/V̇O2max subjects, these values significantly decreased from baseline to experimental tests. No differences were found for WAnT values. During the experimental session, 50% of subjects who performed WAnt/V̇O2max and 81% of subjects who performed V̇O2max/WAnT achieved a valid V̇O2max. Chi squared analysis found the change to be significant in WAnT/V̇O2max subjects only. Therefore, performing the WAnT before V̇O2max sequence significantly reduced the percent of subjects who achieved V̇O2max criteria. These findings indicate that the sequence of V̇O2max testing before a WAnT allowed maximal results similar to expected baseline values.

Area-level and family-level socioeconomic position and body composition trajectories: longitudinal analysis of the UK Millennium Cohort Study

BACKGROUND

Inequalities in the trajectories of body composition in childhood and adolescence have been infrequently studied. Despite the importance of environmental factors in obesity development, little research has looked at area-level socioeconomic position, independent of family socioeconomic position. We aimed to assess how inequalities in body composition develop with age.

METHODS

The Millennium Cohort Study is a longitudinal study of 19 243 families who had a child born between 2000 and 2002 in the UK. Multilevel growth curve models were applied to examine change in fat mass index (FMI), fat free mass index (FFMI; using the Benn index), and fat mass to fat free mass ratio (FM:FFM), measured using Bioelectrical Impedance Analysis, from ages 7 years to 17 years by the Index of Multiple Deprivation (IMD) and household income at baseline.

FINDINGS

Inequalities in FMI and FM:FFM ratio are evident at age 7 years and widen with age. At age 17 years, adolescents in the most disadvantaged IMD group had FMI 0·57 kg/mB (B=Benn parameter; 95% CI 0·43 to 0·70) higher and FM:FFM ratio 0·037 (95% CI 0·026 to 0·047) higher compared with the most advantaged group. Disadvantaged socioeconomic position is associated with higher FFMI but is reversed in adolescence after adjustment for FMI. Inequalities were greater in girls at age 7 years (mean FMI 0·22 kg/mB; 95% CI 0·13 to 0·32) compared with boys of the same age (0·05 kg/mB; -0·04 to 0·15, p=0·3), but widen fastest in boys, especially for FMI, in which there was over an 11 times increase in the inequality from age 7 years of 0·05kg/mB (95% CI -0·04 to 0·15) to 0·62 kg/mB at 17 years (0·42 to 0·82). Inequalities for the IMD were similar to income, and persisted at age 17 years independent of family socioeconomic position.

INTERPRETATION

Childhood and adolescence is an important period to address inequalities in body composition, as they emerge and widen. Policies should consider FFM as well as FM, and inequalities in the environment.

FUNDING

Medical Research Council, Economic and Social Research Council.

Association between Cardiorespiratory Fitness and Circulating Proteins in 50-Year-Old Swedish Men and Women: a Cross-Sectional Study

BACKGROUND AND AIMS

A strong cardiorespiratory fitness is suggested to have beneficial effects on cardiovascular risk; the exact mechanisms underlying the cardioprotective effects of fitness remain uncertain. Our aim was to investigate associations between cardiorespiratory fitness and multiple plasma proteins, in order to obtain insights about physiological pathways associated with the effects of exercise on cardiovascular health.

METHODS

In the Prospective investigation of Obesity, Energy and Metabolism (POEM) study (n=444 adults aged 50 years, 50% women), cardiorespiratory fitness was measured by a maximal exercise test on bicycle ergometer with gas exchange (VO₂peak) normalized for body lean mass (dual-energy X-ray absorptiometry (DXA)). We measured 82 cardiovascular proteins associated with cardiovascular pathology and inflammation in plasma samples with a proximity extension assay.

RESULTS

In sex-adjusted linear regression, VO₂peak was associated with 18 proteins after Bonferroni correction for multiple testing (p<0.0006). Following additional adjustment for fat mass (DXA), fasting glucose (mmol/L), low-density lipoprotein (LDL, mmol/L), smoking status, waist/hip ratio, blood pressure (mmHg), education level, and lpnr (lab sequence number), higher VO₂peak was significantly associated with lower levels of 6 proteins: fatty-acid binding protein-4 (FABP4), interleukin-6 (IL-6), leptin, cystatin-B (CSTB), interleukin-1 receptor antagonist (IL-1RA), and growth differentiation factor 15 (GDF-15), and higher levels of 3 proteins: galanin, kallikrein-6 (KLK6), and heparin-binding EGF-like growth factor (HB-EGF), at nominal p-values (p<0.05).

CONCLUSIONS

We identified multiple novel associations between cardiorespiratory fitness and plasma proteins involved in several atherosclerotic processes and key cellular mechanisms such as inflammation, energy homeostasis, and protease activity, which shed new light on how exercise asserts its beneficial effects on cardiovascular health. Our findings encourage additional studies in order to understand the underlying causal mechanisms for these associations.

The Association between Cardiorespiratory Fitness and Reported Physical Activity with Sleep Quality in Apparently Healthy Adults: A Cross-Sectional Study

BACKGROUND

Recently, poor cardiorespiratory fitness (CRF) has been postulated as an adverse health outcome related to poor sleep quality. However, studies investigating the relationship between CRF and a subjective sleep quality index are scarce. Thus, the current study aimed to investigate the association between CRF and the Pittsburgh Sleep Quality Index (PSQI) in apparently healthy people. The secondary aim was to investigate the association between reported physical activity (PA) and PSQI.

METHODS

Thirty-three healthy male participants volunteered to participate. CRF (VO_2PEAK) was measured via cardiopulmonary exercise testing on a treadmill. A short form of the International Physical Activity Questionnaire (IPAQ) was used to measure PA, and PSQI was used for the sleep quality index.

RESULTS

There was no correlation between CRF and PSQI total score or any component of the PSQI. There was a significant inverse correlation between IPAQ and PSQI total score (r = -0.36, p = 0.04). Categorical data analysis of the two questionnaires revealed that 42.4% of the participants who reported low physical activity also had poor sleep quality.

CONCLUSIONS

The current study showed no association between CRF and the subjective sleep quality index but demonstrated a moderate inverse association between reported PA and subjective sleep quality index. The findings suggest that the more reported PA, the better the overall sleep quality.

Determinants of maximal oxygen uptake in patients with heart failure

Aims

Maximum oxygen uptake (VO_2max) is an essential parameter to assess functional capacity of patients with heart failure (HF). We aimed to identify clinical factors that determine its value, as they have not been well characterized yet.

Methods

We conducted a retrospective, observational, single‐centre study of 362 consecutive patients with HF who underwent cardiopulmonary exercise testing (CPET) as part of standard clinical assessment since 2009–2019. CPET was performed on treadmill, according to Bruce's protocol (n = 360) or Naughton's protocol (n = 2). We performed multivariable linear regression analyses in order to identify independent clinical predictors associated with peak VO_2max.

Results

Mean age of study patients was 57.3 ± 10.9 years, mean left ventricular ejection fraction was 32.8 ± 14.2%, and mean VO_2max was 19.8 ± 5.2 mL/kg/min. Eighty‐nine (24.6%) patients were women, and 114 (31.5%) had ischaemic heart disease. Multivariable linear regression analysis identified six independent clinical predictors of VO_2max, including NYHA class (B coefficient = −2.585; P < 0.001), age (B coefficient per 1 year = −0.104; P < 0.001), tricuspid annulus plane systolic excursion (B coefficient per 1 mm = +0.209; P < 0.001), body mass index (B coefficient per 1 kg/m² = −0.172; P = 0.002), haemoglobin (B coefficient per 1 g/dL = +0.418; P = 0.007) and NT‐proBNP (B coefficient per 1000 pg/mL = −0.142; P = 0.019).

Conclusions

The severity of HF (NYHA class, NT‐proBNP) as well as age, body composition and haemoglobin levels influence significantly exercise capacity. In patients with HF, the right ventricular systolic function is of greater importance for the physical capacity than the left ventricular systolic function.

The Deconditioning Effect of the COVID-19 Pandemic on Unaffected Healthy Children

The COVID-19 pandemic has had devastating direct consequences on the health of affected patients. It has also had a significant impact on the ability of unaffected children to be physically active. We evaluated the effect of deconditioning from social distancing and school shutdowns implemented during the COVID-19 pandemic on the cardiovascular fitness of healthy unaffected children. This is a single-center, retrospective case-control study performed in an urban tertiary referral center. A cohort of 10 healthy children that underwent cardiopulmonary exercise testing after COVID-19 hospital restrictions were lifted was compared to a matched cohort before COVID-19-related shutdowns on school and after-school activities. Comparisons of oxygen uptake (VO₂) max and VO₂ at anaerobic threshold between the pre- and post-COVID-19 cohorts were done. The VO₂ max in the post-COVID cohort was significantly lower than in the pre-COVID cohort (39.1 vs. 44.7, p = 0.031). Only one out of ten patients had a higher VO₂ max when compared to their matched pre-COVID control and was also the only patient with a documented history of participation in varsity-type athletics. The percentile of predicted VO₂ was significantly lower in the post-COVID cohort (95% vs. 105%, p = 0.042). This study for the first time documented a significant measurable decline in physical fitness of healthy children as a result of the COVID-19 pandemic and its associated restrictions. Measures need to be identified that encourage and facilitate regular exercise in children in a way that are not solely dependent on school and organized after-school activities.

Body Fat Is a Predictor of Physical Fitness in Obese Adolescent Handball Athletes

We examined the relationships between body fat (BF) and field measures of physical fitness in adolescent handball players. Twenty nine players (age: 16.6 ± 1.72 years; body mass: 79.8 ± 17.0 kg; height: 1.70 ± 0.12 m; body fat: 27.7 ± 8.67%) from Qatar handball first league performed a series of anthropometric and fitness tests related to their performance in sprinting (i.e., 15 m and 30 m sprint), jumping (i.e., countermovement and squat jumps), throwing (i.e., 3 kg medicine ball seated front throw) and running (i.e., agility T-Half and Yo-Yo intermittent recovery level 1 tests). Significant differences between obese and non-obese groups, classified based on age-stratified %BF norms, were found, with the largest difference being attributed to aerobic performance on the Yo-Yo test. Results indicated no significant relationships between anthropometric variables and sprinting or jumping abilities. %BF predicted a significant 8-15% portion in running performances of agility and aerobic capacity, while the latter were mainly explained by body height and mass. %BF was the only and strongest predictor of throwing performance, being an important determinant of performance in handball. Optimizing %BF should be considered as a training and nutrition goal in order to improve sport performance.

Objective aerobic fitness level and neuropsychological functioning in healthy adolescents and emerging adults: Unique sex effects

Objective

Research suggests positive relationships between aerobic fitness and cognition in older adults; however, limited research has adequately investigated the relationship between objectively measured aerobic fitness and broad cognitive functioning in healthy adolescents and young adults without psychiatric or physical health disorders. Further, studies to date have disproportionately examined males and failed to examine sex differences. Here we examine the relationship between aerobic fitness and neuropsychological functioning in physically healthy youth and whether sex moderates these findings.

Design

Sixty-four healthy emerging adults (16-25 years-old; 32 female) underwent measurement of objective aerobic fitness (VO2 max) and neuropsychological assessment. Exclusion criteria included: left-handedness, prenatal medical issues or alcohol/illicit drug exposure, Axis-I psychiatric disorders, major medical disorders including metabolic conditions such as diabetes, hypertension, hyperlipidemia, major neurologic disorders, LOS greater than 2 min, intellectual disability or learning disability, regular substance use (e.g., greater than biweekly use of cannabis) or positive drug toxicology testing.

Method

Multiple regressions examined VO2 max, sex, sex*VO2interaction in relation to neurocognition, controlling for objectively measured body fat percentage.

Results

Prior to including body fat percentage, higher VO2 max related to improved working memory (Letter-Number Sequencing; p = .03) and selective attention (CPT-II hit response time standard error; p = .03). Aerobic fitness significantly interacted with sex, as higher-fit males had better performance on two sustained attention tasks while females did not demonstrate this pattern (CPT-II variability standard error, p = .047; Ruff 2&7 Total Speed, p = .02). Body fat percentage was positively slower cognitive flexibility (D-KEFS color-word switching/inhibition, p = .046).

Conclusions

VO2 independently predicted better working memory and selective attention. Increased aerobic fitness level related to increased performance on sustained attention tasks in males but not females. Therefore, aerobic fitness may be positively related to better cognitive functioning in physically healthy adolescents and emerging adults without metabolic conditions. Further research into factors (e.g., intensity or type of activity) that may relate to beneficial outcomes by sex are needed.

Association Between Diet Quality and Cardiorespiratory Fitness in Korean Adults: The 2014-2015 National Fitness Award Project

Cardiorespiratory fitness (CRF) is a strong and meaningful indicator for predicting mortality, including cardiovascular disease, as well as simple physical capacity. Healthy eating is thought to be one of the crucial factors associated with an individual's CRF status, although little research has been done on the relationship between healthy eating and CRF. This study aimed to investigate the association between overall diet quality and CRF among Korean adults. The study involved 937 adults (380 men and 557 women) aged 19‒64 years who participated in the 2014‒2015 Korea Institute of Sports Science Fitness Standards project. Diet quality was assessed by the recommended food score (RFS), and CRF was determined by maximal oxygen uptake (VO2max) during a treadmill exercise test. Multiple regression model analyses were stratified by age (19-34, 35-49, and 50-64 years) and sex, because both factors greatly influence CRF. After multivariate adjustment, only the 19‒34 age group in both sexes showed a positive association between RFS and VO2max. Additionally, when physical activity was adjusted, it was still significant in men but only marginally related in women. Our results suggest that better overall diet quality may be associated with a better CRF among young adults aged 19‒34 years in Korea.

Individual Responses to Heat Stress: Implications for Hyperthermia and Physical Work Capacity

Background

Extreme heat events are increasing in frequency, severity, and duration. It is well known that heat stress can have a negative impact on occupational health and productivity, particularly during physical work. However, there are no up-to-date reviews on how vulnerability to heat changes as a function of individual characteristics in relation to the risk of hyperthermia and work capacity loss. The objective of this narrative review is to examine the role of individual characteristics on the human heat stress response, specifically in relation to hyperthermia risk and productivity loss in hot workplaces. Finally, we aim to generate practical guidance for industrial hygienists considering our findings. Factors included in the analysis were body mass, body surface area to mass ratio, body fat, aerobic fitness and training, heat adaptation, aging, sex, and chronic health conditions.

Findings

We found the relevance of any factor to be dynamic, based on the work-type (fixed pace or relative to fitness level), work intensity (low, moderate, or heavy work), climate type (humidity, clothing vapor resistance), and variable of interest (risk of hyperthermia or likelihood of productivity loss). Heat adaptation, high aerobic fitness, and having a large body mass are the most protective factors during heat exposure. Primary detrimental factors include low fitness, low body mass, and lack of heat adaptation. Aging beyond 50 years, being female, and diabetes are less impactful negative factors, since their independent effect is quite small in well matched participants. Skin surface area to mass ratio, body composition, hypertension, and cardiovascular disease are not strong independent predictors of the heat stress response.

Conclusion

Understanding how individual factors impact responses to heat stress is necessary for the prediction of heat wave impacts on occupational health and work capacity. The recommendations provided in this report could be utilized to help curtail hyperthermia risk and productivity losses induced by heat.

A Longitudinal Prospective Study: The Effect of Annual Seasonal Transition and Coaching Influence on Aerobic Capacity and Body Composition in Division I Female Soccer Players

This study assessed how seasonal transitions and coaching influence affect aerobic capacity (AC) and body composition across the annual training cycle (ATC). Eleven division 1 female soccer players were tested after five predesignated time blocks (B1-B5): post-season 2016 (B1), nine-week transition (B2), spring season (B3), pre-season (B4), and post-season 2017 (B5). Height, weight, and body composition (fat-free mass (FFM)) were measured prior to a standardized 5 min treadmill running and dynamic movement warm up before a maximal AC test. Statistical analysis included a 4 × 5 repeated-measures analysis of variance (ANOVA) (dependent variable × time) with the Fishers Least Significant Difference (LSD) post-hoc test when relevant; data are presented as mean ± standard deviation, effect size (ES), and percent change (%). The statistical analysis revealed that the ATC had a significant main effect on AC and FFM (F_3,4 2.81, p = 0.001; η² = 0.22). There were significant increases in AC across the transition period (B1-B2) with reduced training volume (∆ + 12.9%, p = 0.001; ES = 0.50) while AC and FFM peaked after the spring season with directed concurrent training paired with adequate rest B1-B3 (∆ + 16.4%, p < 0.01; ES = 0.81). AC decreased across the pre-season with indirect training (B3-B4) (∆ - 7.0%, p = 0.02; ES = 0.50) and remained suppressed without change (p > 0.05) across the competitive season (B4-B5). Rest, concurrent training, and directed training positively affected AC, while indirect training and high training loads with little rest negatively affected AC.

Interindividual Variation in Cardiorespiratory Fitness: A Candidate Gene Study in Han Chinese People

Cardiorespiratory fitness, as assessed through peak oxygen uptake (VO2peak), is a powerful health indicator. We aimed to evaluate the influence of several candidate causal genetic variants on VO2peak level in untrained Han Chinese people. A total of 1009 participants (566 women; age [mean ± SD] 40 ± 14 years, VO2peak 29.9 ± 7.1 mL/kg/min) performed a maximal incremental cycling test for VO2peak determination. Genomic DNA was extracted from peripheral whole blood, and genotyping analysis was performed on 125 gene variants. Using age, sex, and body mass as covariates, and setting a stringent threshold p-value of 0.0004, only one single nucleotide polymorphism (SNP), located in the gene encoding angiotensin-converting enzyme (rs4295), was associated with VO2peak (β = 0.87; p < 2.9 × 10-4). Stepwise multiple regression analysis identified a panel of three SNPs (rs4295 = 1.1%, angiotensin II receptor type 1 rs275652 = 0.6%, and myostatin rs7570532 = 0.5%) that together accounted for 2.2% (p = 0.0007) of the interindividual variance in VO2peak. Participants carrying six 'favorable' alleles had a higher VO2peak (32.3 ± 8.1 mL/kg/min) than those carrying only one favorable allele (24.6 ± 5.2 mL/kg/min, p < 0.0001). In summary, VO2peak at the pre-trained state is partly influenced by several polymorphic variations in candidate genes, but they represent a minor portion of the variance.

Consumption of Cooked Black Beans Stimulates a Cluster of Some Clostridia Class Bacteria Decreasing Inflammatory Response and Improving Insulin Sensitivity

There is limited information on the effect of black beans (BB) as a source of protein and resistant starch on the intestinal microbiota. The purpose of the present work was to study the effect of cooked black beans with and without high fat and sugar (HF + S) in the diet on body composition, energy expenditure, gut microbiota, short-chain fatty acids, NF-κB, occluding and insulin signaling in a rat model and the area under the curve for glucose, insulin and incretins in healthy subjects. The consumption of BB reduced the percentage of body fat, the area under the curve of glucose, serum leptin, LPS, glucose and insulin concentrations and increased energy expenditure even in the presence of HF + S. These results could be mediated in part by modification of the gut microbiota, by increasing a cluster of bacteria in the Clostridia class, mainly R. bromii, C. eutactus, R. callidus, R. flavefaciens and B. pullicaecorum and by an increase in the concentration of fecal butyrate. In conclusion, the consumption of BB can be recommended to prevent insulin resistance and metabolic endotoxemia by modifying the gut microbiota. Finally, the groups fed BB showed lower abundance of hepatic FMO-3, even with a high-fat diet protecting against the production of TMAO and obesity.

A Randomized Controlled Trial Investigating the Effects of Undulatory, Staggered, and Linear Load Manipulations in Aerobic Training on Oxygen Supply, Muscle Injury, and Metabolism in Male Recreational Runners

Background

Taper is considered as a strategy to avoid overtraining and increase peak performance in athletes. Because aerobic exercise increases the level and duration of independence during the lifespan, the participation of recreational athletes has increased in running events around the world. However, the effects of using load reduction in their training and aerobic performance are still not well known.

Objectives

Our goal was to compare load manipulations, using tapering-like periods in the end of recreational athletes training evaluating alterations in oxygen supply, muscle injury, and metabolism markers.

Methods

Healthy males (n = 88, 20–35 years old) were randomly distributed in groups using a combination of two mesocycles of 4 weeks, undulatory and staggered, with two daily microcycles, undulatory and linear. Undulatory-undulatory (Und-Und) and undulatory-linear (Und-Lin) groups had load reduction in the final week of training while the staggered-undulatory (Sta-Und) and staggered-linear (Sta-Lin) groups did not. Cardiorespiratory capacity (V̇O_2max), body mass index (BMI), and body fat % were evaluated. Blood samples were also collected to analyze hematocrit (Ht), mean corpuscular hemoglobin (MCHC), circulating levels of hemoglobin (Hb), creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea (U), cortisol (C), free testosterone (FT), and free T/C ratio.

Results

After 8 weeks of training, Und-Und had the highest trend to increase V̇O_2max. Both Und-Und and Sta-Lin reduced body fat %. Und-Und showed a significant increase in MCHC, T and Free T/C ratio, a positive trend to increase Ht% and Hb levels, and a trend to decrease CK, LDH, and C circulating levels. Sta-Lin presented a trend to decrease Ht% and Hb levels, a significant increase in CK, LDH, AST, ALT circulating levels, and a decrease in Free T/C ratio.

Conclusion

The use of daily undulatory training load provides better gains for aerobic fitness while the use of staggered load, mainly associated with linear load, promotes inadequate recovery in recreational runners.

Fat-free mass index is superior to body mass index as a novel risk factor for prolonged air leak complicating video-assisted thoracoscopic surgery lobectomy for non-small-cell lung cancer

Background

To evaluate whether fat-free mass index (FFMI) could be predictive of prolonged air leak (PAL) complicating video-assisted thoracoscopic (VATS) lobectomy for non-small-cell lung cancer (NSCLC).

Methods

A retrospective study was conducted on the prospectively-maintained database in our institution between January 2015 and July 2017. The gender-specific median values of FFMI for males and females were applied as their respective cutoffs to stratify patients into low-FFMI group and high-FFMI group in initial univariable analyses. An effective multivariable logistic-regression analysis was then performed to demonstrate the predictive value of dichotomized FFMI.

Results

There were 1,091 surgical patients with NSCLC included (616 males and 475 females), with a PAL incidence of 14.6%. The median FFMI values among males and females were 17.3 and 14.6 kg/m², respectively. PAL cases in both male (16.9±1.5 vs. 17.4±1.5 kg/m²; P=0.002) and female (14.0±0.9 vs. 14.6±1.1 kg/m²; P<0.001) groups had a significantly lower mean FFMI than that of non-PAL cases. The incidence of PAL was significantly increased in male patients with FFMI <17.3 kg/m² (23.7% vs. 14.3%; P=0.003) and female patients with FFMI <14.6 kg/m² (12.7% vs. 5.0%; P=0.003). Lower dichotomized FFMI was also significantly associated with prolonged time to air leak cessation and length of stay (LOS). Finally, multivariable logistic-regression analysis indicated that lower dichotomized FFMI [odds ratio (OR) =1.98; 95% confidence interval (CI): 1.33-2.96; P=0.001] could independently predict the occurrence of PAL.

Conclusions

FFMI acts as an excellent categorical risk factor for PAL complicating VATS lobectomy and shows a much superior significance than body mass index (BMI) in terms of the prediction of PAL.

Plant-Based Diets for Cardiovascular Safety and Performance in Endurance Sports

Studies suggest that endurance athletes are at higher-than-average risk for atherosclerosis and myocardial damage. The ability of plant-based regimens to reduce risk and affect performance was reviewed. The effect of plant-based diets on cardiovascular risk factors, particularly plasma lipid concentrations, body weight, and blood pressure, and, as part of a healthful lifestyle, reversing existing atherosclerotic lesions, may provide a substantial measure of cardiovascular protection. In addition, plant-based diets may offer performance advantages. They have consistently been shown to reduce body fat, leading to a leaner body composition. Because plants are typically high in carbohydrate, they foster effective glycogen storage. By reducing blood viscosity and improving arterial flexibility and endothelial function, they may be expected to improve vascular flow and tissue oxygenation. Because many vegetables, fruits, and other plant-based foods are rich in antioxidants, they help reduce oxidative stress. Diets emphasizing plant foods have also been shown to reduce indicators of inflammation. These features of plant-based diets may present safety and performance advantages for endurance athletes. The purpose of this review was to explore the role of nutrition in providing cardioprotection, with a focus on plant-based diets previously shown to provide cardiac benefits.

Mechanisms of Aerobic Exercise Impairment in Diabetes: A Narrative Review

The prevalence of diabetes in the United States and globally has been rapidly increasing over the last several decades. There are now estimated to be 30.3 million people in the United States and 422 million people worldwide with diabetes. Diabetes is associated with a greatly increased risk of cardiovascular mortality, which is the leading cause of death in adults with diabetes. While exercise training is a cornerstone of diabetes treatment, people with diabetes have well-described aerobic exercise impairments that may create an additional diabetes-specific barrier to adding regular exercise to their lifestyle. Physiologic mechanisms linked to exercise impairment in diabetes include insulin resistance, cardiac abnormalities, mitochondrial function, and the ability of the body to supply oxygen. In this paper, we highlight the abnormalities of exercise in type 2 diabetes as well as potential therapeutic approaches.