VO(2) reserve and the minimal intensity for improving cardiorespiratory fitness

Cut-off values for estimated cardiorespiratory fitness in terms of physical functioning among middle-aged to older adults

BACKGROUND

Cardiorespiratory fitness is linked to various health outcomes. This study aimed to establish cut-off values for estimated cardiorespiratory fitness associated with poor physical functioning in middle-aged to older adults.

METHODS

A total of 2638 participants (1083 males), aged 40-69 years, performed a 6-min walking test (6MWT) to estimate cardiorespiratory fitness (VO2max) and completed a health-related questionnaire. Physical functioning was assessed using four outcomes: perceived health, perceived fitness, difficulties in 2-km walking, and difficulties in climbing several stairs. Receiver operator characteristics (ROC) curves were used to determine cut-off values for estimated VO2max and 6MWT distance linked to poor physical functioning based on the four outcomes. Analyses were done separately for males and females, and for 40- to 49-, 50- to 59-, and 60- to 69-year-old groups. Multinomial regression was used to analyze differences between fitness thirds in outcome variables.

RESULTS

ROC analyses were significant for all outcomes (AUC 0.686-0.834, P<0.001). In the total group, cut-off values for estimated VO2max were 29.9-30.2 mL/kg/min, and for walking distance, 588.0-599.5 m. Cut-off values decreased with age, and mean differences between males and females were 3.3 mL/kg/min and 33 m. All cut-off values were within ±1.3 mL/kg/min of the lower fitness tertile. The odds ratios of having poor physical functioning in the middle and high fitness thirds were less than 0.50 compared to low fitness third.

CONCLUSIONS

VO2max of 30 mL/kg/min and 600-m walking distance seemed reasonable cut-off values for poor physical functioning. Exceeding the currently proposed thresholds is a desirable goal to avoid consequences of insufficient fitness.

Heart Rate Index-An Alternative Exercise-Based Equation for Estimating Peak VO 2

PURPOSE

Heart rate (HR)-derived variables (HR reserve [HR peak  - HR rest ], chronotropic indices [attenuated HR response to exercise], HR recovery [attenuated HR response to exercise recovery], and peak HR index [HR peak /HR rest ]) together with peak oxygen uptake (VO 2peak ) are potential prognostic variables for cardiovascular and all-cause mortality. However, heart rate index (HRI) has not been established as a surrogate for VO 2peak , whether measured (Meas) or estimated (Est), during cycle ergometry (CE) and/or treadmill testing (TT).

METHODS

HR-derived prognostic variables to assess cardiovascular outcomes were identified from 150 studies obtained from MEDLINE and Google Scholar searches. The Meas CE/TT-VO 2peak was reported in 81 studies (21 773 participants) and Est CE/TT-VO 2peak in 69 studies (331 435 participants). Using the HRI equation with metabolic equivalent (METs) = 6 × HRI - 5 (where HRI = peak HR/resting HR), HRI-VO 2peak was calculated from HR data reported in the 150 studies. The HRI-VO 2peak was then compared against group mean data for both Meas CE/TT-VO 2peak and Est CE/TT-VO 2peak .

RESULTS

The difference between Meas CE/TT-VO 2peak and HRI-VO 2peak was 1% (7.15 ± 3.25 METs vs 7.08 ± 3.02 METs [ P = .833], respectively). By comparison, the difference between Est CE/TT-VO 2peak and HRI-VO 2peak was 25.6% (8.94 ± 2.36 METs vs 7.12 ± 2.27 METs [ P < .001], respectively). Moreover, HRI equation estimation of VO 2peak showed greater overprediction for TT, 26.6%, than for CE, 11.9%.

CONCLUSIONS

The Meas-VO 2peak and HRI-VO 2peak agreed closely. When compared with HRI-VO 2peak , Est-VO 2peak from currently used exercise-based equations shows significant overprediction. Use of HRI and/or Fitness Registry and the Importance of Exercise National Database (FRIEND) registry equations warrant consideration for more accurately estimating VO 2peak .

Using Free-Living Heart Rate Data as an Objective Method to Assess Physical Activity: A Scoping Review and Recommendations by the INTERLIVE-Network Targeting Consumer Wearables

Wearable technologies open up new avenues for the assessment of individual physical activity behaviour. Particularly, free-living heart rate (HR) data assessed by optical sensors are becoming widely available. However, while an abundancy of scientific information and guidance exists for the processing of raw acceleration data, no universal recommendations for the utilization of continuous HR recordings during free-living conditions are available. Towards Intelligent Health and Well-Being: Network of Physical Activity Assessment (INTERLIVE®) is a joint European initiative of six universities and one industrial partner. The consortium was founded in 2019 and strives towards developing best-practice recommendations in the context of consumer wearables and smartphones. The aim of this scoping review (following PRISMA-ScR procedures) and recommendations was to provide best-practice protocols for deriving individual physical activity profiles from continuous HR recordings by wearables. The recommendations were developed through an initial scoping review, grey literature searches of promotional material and user manuals of leading wearable manufacturers as well as evidence-informed discussions among the members of the INTERLIVE®-network. The scoping review was performed on the generic domains required for physical activity assessment, namely: (1) 'assessment of maximal heart rate', (2) 'determination of basal and/or resting heart rate' and (3) 'heart rate-derived intensity zones', for which we finally included a total of 72, 2 and 11 eligible papers, respectively. Gathering recent knowledge, we provide a decision tree and detailed recommendations for the analysis of free-living HR data to derive individual physical activity profiles. Moreover, we also provide examples of HR-metric calculations that help to illustrate data processing and reporting.

Cardiorespiratory fitness, physical activity, and fatigue three months after first-ever ischemic stroke

BACKGROUND

Research on cardiorespiratory fitness (CRF) in relation to physical activity (PA) and fatigue after stroke is limited. Increased knowledge of interrelationships between these factors can help optimize rehabilitation strategies and improve health-outcomes.

OBJECTIVES

We aimed to: 1) evaluate CRF, PA, and fatigue, 2) characterize patients with impaired versus non-impaired CRF, and 3) examine associations of CRF with PA and fatigue, three months after first-ever ischemic stroke.

METHODS

In this cross-sectional study CRF was measured as peak oxygen uptake (VO2peak) by cardiopulmonary exercise testing. PA was measured using accelerometers. Fatigue was assessed with the 7-item Fatigue Severity Scale (FSS).

RESULTS

The sample (n=74, mean age 64±13 years, 36% women) had a mean VO2peak of 27.0±8.7 (86% of predicted). Fifty-one percent met the World Health Organization's recommendation of ≥150 min of moderate PA/week. Mean steps-per-day was 9316±4424 (113% of predicted). Thirty-five percent of the sample had moderate-to-high fatigue (FSS≥4), mean FSS score was 3.2±1.8.  Patients with impaired CRF (VO2peak<80% of predicted) had higher body-fat-percent (p<0.01), less moderate-to-vigorous PA (MVPA) (p<0.01) and a trend toward higher fatigue (p=0.053) compared to the non-impaired. Backward regression analysis showed that higher CRF was associated with more MVPA (unstandardized beta [95% CI]: 0.38 [0.15, 0.63], p=0.002) and less fatigue (unstandardized beta [95% CI]: -3.9 [-6.4, -1.6], p=0.004).

CONCLUSIONS

Stroke patients had lower CRF compared to reference values. Impaired CRF was mainly related to overweight. Higher CRF was associated with more MVPA and less fatigue. Exercise after stroke may be especially beneficial for patients with impaired CRF.

Exercise intensity and mortality in overweight and obese patients with chronic kidney disease: longitudinal analysis (1999-2016)

BACKGROUND

Chronic kidney disease (CKD) and overweight/obesity are significant global public health issues. Appropriate free-time physical activity (PA) is essential for overweight/obese patients with chronic kidney disease, but specific guidelines are lacking. The present study was conducted to determine the association between PA and all-cause mortality in these patients.

METHODS

Data from 3,434 overweight/obese adults with CKD from the 1999-2016 National Health and Nutrition Examination Surveys were analyzed. Associations between clinical/laboratory findings and PA intensity (moderate and vigorous) were investigated. The all-cause mortality of patients in different PA categories were compared by Kaplan-Meier analysis. Factors associated with all-cause mortality were determined using a Cox proportional hazards model. A restricted cubic spline was employed to obtain a more flexible and detailed representation of the relationship between PA intensity and all-cause mortality, with better predictive capability.

RESULTS

The Kaplan-Meier analysis revealed that greater all-cause mortality was associated with < 10 min/week moderate/vigorous PA (log-rank p < 0.001). A greater survival probability was associated with ≥ 150 min/week vigorous PA or 10-149 min/week moderate PA (log-rank p < 0.001). Age, gender, vigorous PA, smoking status, alcohol consumption, diabetes status, eGFR, serum albumin level, uric acid level, and blood urea nitrogen level were identified as factors associated independently with mortality in the Cox proportional hazards analysis. The restricted cubic splines revealed that these relationships were non-linear (all p < 0.05). Kaplan-Meier analysis of data from patients who engaged in 10-450 min/week moderate/vigorous PA revealed significant differences between the 0-74-min/week and other vigorous PA groups (all log-rank p < 0.001).

CONCLUSIONS

Extended durations of vigorous PA are associated with reduced all-cause mortality in overweight/obese patients with CKD. Clinicians should recommend vigorous free-time PA to these patients, and public health interventions should target this goal to maximize patient health.

Physical activity volume, frequency, and intensity: Associations with hypertension and obesity over 21 years in Australian women

BACKGROUND

Optimal patterns of accrual of recommended levels of physical activity (PA) for prevention of hypertension and obesity are not known. The overall aim of this study was to investigate whether different patterns of accumulation of PA are differentially associated with hypertension and obesity in Australian women over 21 years. Specifically, we investigated whether, for the same weekly volume of PA, the number of sessions (frequency) and vigorousness of PA (intensity) were associated with a reduction in the occurrence of hypertension and obesity in women.

METHODS

Data from the 1973-1978 and 1946-1951 cohorts of the Australian Longitudinal Study on Women's Health were analyzed (n = 20,588; 12%-16% with a Bachelor's or higher degree). Self-reported PA, hypertension, height, and weight were collected using mail surveys every 3 years from 1998/2000 to 2019/2021. Generalized Estimating Equation models with a 3-year lag model were used to investigate the association of PA volume (metabolic equivalent min/week) (none; 33-499; 500-999; ≥1000, weekly frequency (none; 1-2 times; 3-4 times; 5-7 times; ≥8 times), and the proportion of vigorous PA to total volume of PA (none; 0%; 1%-33%; 34%-66%; 67%-100%) with odds of hypertension and obesity from 2000 to 2021.

RESULTS

The cumulative incidence of hypertension was 6% in the 1973-1978 and 23% in the 1946-1951 cohort; 27% of women in the 1973-1978; and 15% in the 1946-1951 cohort developed obesity over the period. Overall, a higher volume of PA was associated with reduced odds of hypertension and obesity. When the volume of PA was considered, the odds of hypertension did not vary according to the frequency or intensity of PA. However, increased proportion of vigorous PA to the total volume of PA was associated with a small additional reduction in the risk of obesity.

CONCLUSION

PA volume appears to be more important than the pattern of accumulation for the prevention of hypertension and obesity. Incorporating more sessions, particularly of vigorous-intensity PA, may provide extra benefits for the prevention of obesity.

Association of Occupational and Leisure-Time Physical Activity With Allostatic Load

INTRODUCTION

Leisure-time physical activity decreases allostatic load, a measure of burden of chronic stress. However, the role of occupational physical activity is unknown. This study examined associations of occupational physical activity and leisure-time physical activity with allostatic load among workers in the U.S.

METHODS

This cross-sectional study included 6,944 U.S. workers aged 20-64 years from the National Health and Nutrition Examination Survey (2007-2018). Physical activity was assessed using the Global Physical Activity Questionnaire. Allostatic load was calculated using biomarkers of cardiovascular, metabolic, and immune systems. Associations of occupational physical activity and leisure-time physical activity with allostatic load were examined using negative binomial regressions. Analyses were conducted between August 2022 and March 2023.

RESULTS

Vigorous leisure-time physical activity inversely associated with allostatic load among all workers (count ratio=0.68, 95% CI=0.62, 0.76) and in each sex- and age-stratified group as well as in each race/ethnicity-stratified group. Vigorous occupational physical activity positively associated with allostatic load only among females aged 20-44 years (1.38, 95% CI=1.10, 1.73). Inverse associations of vigorous leisure-time physical activity with allostatic load were similar in young females with high or low vigorous occupational physical activity.

CONCLUSIONS

Increasing vigorous leisure-time physical activity associates with a lower allostatic load for all workers, whereas increasing vigorous occupational physical activity associates with a higher allostatic load only in young females. Promoting vigorous leisure-time physical activity reduces allostatic load among young females with either low or high vigorous occupational physical activity.

Endurance training volume cannot entirely substitute for the lack of intensity

PURPOSE

Very low intensity endurance training (LIT) does not seem to improve maximal oxygen uptake. The purpose of the present study was to investigate if very high volume of LIT could compensate the lack of intensity and is LIT affecting differently low and high intensity performances.

METHODS

Recreationally active untrained participants (n = 35; 21 females) cycled either LIT (mean training time 6.7 ± 0.7 h / week at 63% of maximal heart rate, n = 16) or high intensity training (HIT) (1.6 ± 0.2 h /week, n = 19) for 10 weeks. Two categories of variables were measured: Low (first lactate threshold, fat oxidation at low intensity exercise, post-exercise recovery) and high (aerobic capacity, second lactate threshold, sprinting power, maximal stroke volume) intensity performance.

RESULTS

Only LIT enhanced pooled low intensity performance (LIT: p = 0.01, ES = 0.49, HIT: p = 0.20, ES = 0.20) and HIT pooled high intensity performance (LIT: p = 0.34, ES = 0.05, HIT: p = 0.007, ES = 0.48).

CONCLUSIONS

Overall, very low endurance training intensity cannot fully be compensated by high training volume in adaptations to high intensity performance, but it nevertheless improved low intensity performance. Therefore, the intensity threshold for improving low intensity performance is lower than that for improving high intensity performance. Consequently, evaluating the effectiveness of LIT on endurance performance cannot be solely determined by high intensity performance tests.

Need to Revise Classification of Physical Activity Intensity in Older Adults? The Use of Estimated METs, Measured METs, and V̇O2 Reserve

BACKGROUND

Multiples of resting metabolic rate (RMR) are often used to classify physical activity intensity, a concept known as the metabolic equivalent of task (MET). However, the METs metrics may misclassify physical activity intensity in older adults because of age-related changes in RMR and maximal aerobic capacity (V˙O2max). This study aimed to (i) compare classifications of activity intensity by estimated (METsestimated) and measured (METsmeasured) METs and (ii) compare physical activity classified by absolute (METsmeasured) versus relative intensity (%V˙O2Reserve) in older adults.

METHODS

Ninety-eight adults aged 75-90 years participated in the study. RMR and V˙O2 during sitting, standing, daily activities, and 6-minute walking test were measured. V˙O2Reserve was defined as the difference between V˙O2max and RMR. Moderate and vigorous intensity was classified as 3 and 6 METs and 40% and 60% of V˙O2Reserve, respectively. Paired t tests and a confusion matrix were used to investigate aims 1 and 2, respectively.

RESULTS

METsmeasured was 24% lower than the standard 1 MET of 3.5 mL O2·min-1·kg-1. METsestimated underestimated the intensity during daily and walking activities when compared to METsmeasured. Nevertheless, when comparing METsmeasured to percentages of V˙O2Reserve, a mismatch was shown for moderate intensity in 47%-67% of the participants during daily activities and 21% of the participants during self-selected gait speed.

CONCLUSIONS

Applying METsestimated for older adults leads to potential underestimation of physical activity intensity, suggesting that current classification metrics should be revised for older adults. V˙O2Reserve is a candidate metric for establishing precise physical activity intensity cut points for older adults. Clinical Trials Registration Number: NCT04821713.

Effect of High-Intensity Interval Training and Moderate-Intensity Continuous Training in People With Poststroke Gait Dysfunction: A Randomized Clinical Trial

BACKGROUND

The exercise strategy that yields the greatest improvement in both cardiorespiratory fitness (V ̇ O 2 peak $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$ ) and walking capacity poststroke has not been determined. This study aimed to determine whether conventional moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT) have different effects on V ̇ O 2 peak $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$ and 6-minute walk distance (6MWD).

METHODS AND RESULTS

In this 24-week superiority trial, people with poststroke gait dysfunction were randomized to MICT (5 days/week) or HIIT (3 days/week with 2 days/week of MICT). MICT trained to target intensity at the ventilatory anaerobic threshold. HIIT trained at the maximal tolerable treadmill speed/grade using a novel program of 2 work-to-recovery protocols: 30:60 and 120:180 seconds. V̇O2 and heart rate was measured during performance of the exercise that was prescribed at 8 and 24 weeks for treatment fidelity. Main outcomes were change in V ̇ O 2 peak $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$ and 6MWD. Assessors were blinded to the treatment group for V ̇ O 2 peak $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$ but not 6MWD. Secondary outcomes were change in ventilatory anaerobic threshold, cognition, gait-economy, 10-meter gait-velocity, balance, stair-climb performance, strength, and quality-of-life. Among 47 participants randomized to either MICT (n=23) or HIIT (n=24) (mean age, 62±11 years; 81% men), 96% completed training. In intention-to-treat analysis, change in V ̇ O 2 peak $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$ for MICT versus HIIT was 2.4±2.7 versus 5.7±3.1 mL·kg-1·min-1 (mean difference, 3.2 [95% CI, 1.5-4.8]; P<0.001), and change in 6MWD was 70.9±44.3 versus 83.4±53.6 m (mean difference, 12.5 [95% CI, -17 to 42]; P=0.401). HIIT had greater improvement in ventilatory anaerobic threshold (mean difference, 2.07 mL·kg-1·min-1 [95% CI, 0.59-3.6]; P=0.008). No other between-group differences were observed. During V̇O2 monitoring at 8 and 24 weeks, MICT reached 84±14% to 87±18% of V ̇ O 2 peak $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$ while HIIT reached 101±22% to 112±14% of V ̇ O 2 peak $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$ (during peak bouts).

CONCLUSIONS

HIIT resulted in more than a 2-fold greater and clinically important change in V ̇ O 2 peak $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$ than MICT. Training to target (ventilatory anaerobic threshold) during MICT resulted in ~3 times the minimal clinically important difference in 6MWD, which was similar to HIIT. These findings show proof of concept that HIIT yields greater improvements in cardiorespiratory fitness than conventional MICT in appropriately screened individuals.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03006731.

Demarcation of Intensity From 3 to 5 Zones Aids in Understanding Physiological Performance Progression in Highly Trained Under-23 Rowing Athletes

ABSTRACT

Watts, SP, Binnie, MJ, Goods, PSR, Hewlett, J, Fahey-Gilmour, J, and Peeling, P. Demarcation of intensity from 3 to 5 zones aids in understanding physiological performance progression in highly trained under-23 rowing athletes. J Strength Cond Res 37(11): e593-e600, 2023-The purpose of this investigation was to compare 2 training intensity distribution models (3 and 5 zone) in 15 highly trained rowing athletes ( n = 8 male; n = 7 female; 19.4 ± 1.1 years) to determine the impact on primary (2,000-m single-scull race) and secondary (2,000-m ergometer time trial, peak oxygen consumption [V̇O 2 peak], lactate threshold 2 [LT2 power]) performance variables. Performance was assessed before and after 4 months training, which was monitored through a smart watch (Garmin Ltd, Olathe, KS) and chest-strap heart rate (HR) monitor (Wahoo Fitness, Atlanta, GA). Two training intensity distribution models were quantified and compared: a 3-zone model (Z1: between 50% V̇O 2 peak and lactate threshold 1 (LT1); Z2: between LT1 and 95% LT2; Z3: >95% LT2) and a 5-zone model (T1-T5), where Z1 and Z3 were split into 2 additional zones. There was significant improvement in LT2 power for both male (4.08% ± 1.83, p < 0.01) and female (3.52% ± 3.38, p = 0.02) athletes, with male athletes also demonstrating significant improvement in 2,000-m ergometer time trial (2.3% ± 1.92, p = 0.01). Changes in V̇O 2 peak significantly correlated with high-quality aerobic training (percent time in T2 zone; r = 0.602, p = 0.02), whereas changes in LT2 power significantly correlated with "threshold" training (percent time in T4 zone; r = 0.529, p = 0.04). These correlations were not evident when examining intensity distribution through the 3-zone model. Accordingly, a 5-zone intensity model may aid in understanding the progression of secondary performance metrics in rowing athletes; however, primary (on-water) performance remains complex to quantify.

Fourteen-Days Spirulina Supplementation Increases Hemoglobin, but Does Not Provide Ergogenic Benefit in Recreationally Active Cyclists: A Double-Blinded Randomized Crossover Trial

Spirulina supplementation has been reported to increase hemoglobin concentration as well as a variety of cardiorespiratory and lactate-based performance parameters during maximal and submaximal states of exercise. This study investigates the efficacy of supplementing a 6 g/day dosage of spirulina for 14-days in recreationally active individuals, analyzing cardiorespiratory parameters during maximal and submaximal cycling as well as the potential mechanistic role of hemoglobin augmentation. 17 recreationally active individuals (Male = 14, Female = 3, Age 23 ± 5 years, V̇O2max 43.3 ± 8.6 ml/min·kg) ingested 6 g/day of spirulina or placebo for 14-days in a double-blinded randomized crossover study, with a 14-day washout period between trials. Participants completed a 20-min submaximal cycle at 40% maximal power output (WRmax), followed by a V̇O2max test. Hemoglobin (g/L), WRmax (watts), time to fatigue (seconds), heart rate (bpm), oxygen uptake (ml/min·kg), RER and blood lactate response (mmol/L) were measured and compared between conditions. Cardiorespiratory variables were recorded at 5-min intervals and lactate was measured at 10-min intervals during the submaximal exercise. There was a significant 3.4% increase in hemoglobin concentration after spirulina supplementation in comparison to placebo (150.4 ± 9.5 g/L Vs 145.6 ± 9.4 g/L, p = 0.047). No significant differences existed between either condition in both testing protocols for V̇O2max, WRmax, time to fatigue, heart rate, oxygen uptake, RER and blood lactate response (p > 0.05). 14-days of spirulina supplementation significantly improved hemoglobin concentration but did not lead to any considerable ergogenic improvements during maximal or submaximal exercise at a 6 g/day dosage in recreationally active individuals whilst cycling.

Ventilatory Threshold Related to V̇O 2 reserve, Heart Rate Reserve, and Rating of Perceived Exertion in a Large Varied Sample

PURPOSE

ACSM guidelines state that aerobic exercise intensity should be 30%/40% to 89% V̇O 2 reserve (V̇O 2 R) or heart rate reserve (HRR). Determining the proper intensity within this range is the "art" of exercise prescription, often relying on rating of perceived exertion (RPE) as the adjunctive intensity modulator. Current guidelines do not consider the use of ventilatory threshold (VT) due to the need for specialized equipment and methodological issues. The purpose of this investigation was to evaluate VT related to V̇O 2peak , V̇O 2 R, HRR, and RPE across the full spectrum of very low to very high V̇O 2peak values.

METHODS

Eight hundred and sixty-three records of exercise tests were retrospectively examined. Data were stratified for V̇O 2peak , activity level, age, test modality, and sex.

RESULTS

When stratified for V̇O 2peak , V̇O 2 at VT (V̇O 2 vt) had a lower mean value of ~14 mL·kg -1 ·min -1 in the lowest fit, rose gradually until median V̇O 2peak , and rose steeply thereafter. When graphed relative to V̇O 2peak , V̇O 2 vt as a percentage of V̇O 2 R (VT%V̇O 2 R) resembled a U-shaped curve, with a nadir ~43% V̇O 2 R at V̇O 2peak ~40 mL·kg -1 ·min -1 . Average VT%V̇O 2 R increased to ~75% in groups with the lowest or highest V̇O 2peak . There was a large variance in the value of VT at all V̇O 2peak levels. Mean RPE at VT was 12.5 ± 0.93, regardless of V̇O 2peak .

CONCLUSIONS

Given the relationship of VT as the transition from moderate- to higher-intensity exercise, these data may help the understanding of aerobic exercise prescription in persons across the spectrum of V̇O 2peak values.

Physical Activity Accumulated Across Adulthood and Resting Heart Rate at Age 41-46 Years in Women: Findings From the Menarche to Premenopause Study

OBJECTIVE

To investigate the association between physical activity accumulated from early (age 22-27 y) to mid (age 40-45 y) adulthood and resting heart rate at age 41-46 years in women.

METHODS

Data were from 479 participants in the 1973-1978 cohort of the Australian Longitudinal Study on Women's Health. Participants reported physical activity every 3 years from age 22-27 years to 40-45 years. Linear regression models were used to investigate the associations of a cumulative physical activity score (average physical activity across 18 y; up to 7 surveys) and changes in physical activity from age 22-33 years to 34-45 years with resting heart rate at age 41-46 years.

RESULTS

Average resting heart rate at age 41-46 years was 75 (SD: 11) beats per minute. An inverse nonlinear dose-response association between cumulative physical activity and resting heart rate was observed. Overall, accumulation of physical activity was associated with lower resting heart rate regardless of the age when physical activity was accumulated. Women in the highest tertile of physical activity at both age 22-33 years and 34-45 years had a resting heart rate, on average, 8 beats per minute lower (95% confidence interval, -11.42 to -4.69) than those consistently in the lowest tertile of physical activity.

CONCLUSION

Accumulating physical activity, irrespective of timing, appears to provide cardiovascular health benefits for women before the transition to menopause.

Association Between the Combined Effects of Physical Activity Intensity and Particulate Matter and All-Cause Mortality in Older Adults

OBJECTIVE

To investigate the association between the combined effects of physical activity (PA) intensity and particulate matter ≤10 μm in diameter (PM10) and mortality in older adults.

METHODS

This nationwide cohort study included older adults without chronic heart or lung disease who engaged in regular PA. Physical activity was assessed by a standardized, self-reported questionnaire that asked the usual frequency of PA sessions with low (LPA), moderate (MPA), or vigorous intensity (VPA). Each participant's annual average cumulative PM10 was categorized as low to moderate and high PM10 on the basis of a cutoff value of 90th percentile.

RESULTS

A total of 81,326 participants (median follow-up, 45 months) were included. For participants engaged in MPA or VPA sessions, every 10% increase in the proportion of VPA to total PA sessions resulted in a 4.9% (95% CI, 1.0% to 9.0%; P=.014) increased and 2.8% (95% CI, -5.0% to -0.5%; P=.018) decreased risk of mortality for those exposed to high and low to moderate PM10, respectively (Pinteraction, <.001). For participants engaged only in LPA or MPA sessions, every 10% increase in the proportion of MPA to total PA sessions resulted in a 4.8% (95% CI, -8.9% to -0.4%; P=.031) and 2.3% (95% CI, -4.2% to -0.3%; P=.023) decreased risk of mortality for those exposed to high and low to moderate PM10, respectively (Pinteraction, .096).

CONCLUSION

We found that for the same level of total PA, MPA was associated with delayed mortality whereas VPA was associated with hastened mortality of older adults in high levels of PM10.

Prescription and Effects of Cardiorespiratory Training in Individuals with Intellectual Disability: A Systematic Review

This study aims to systematize effects of cardiorespiratory training (CT) programs in individuals with intellectual disability (ID) and identifying the fundamental and structuring aspects for the prescription of CT. This systematic review was carried out through four databases (Pubmed, Web of Science, Scopus, and SPORTDiscus), considering data from the period between 2013 and 2022. From 257 studies, 12 studies were included in this systematic review. Three studies used interval CT, while seven used continuous CT. Seven were carried out in the population with Down syndrome, while only three were carried out with participants with ID. The CT programs had the following characteristics: duration of 8 to 12 weeks, weekly frequency of three sessions, for 20 to 60 min, the intensity of 50% to 80% of maximal heart rate or 70% to 80% of peak oxygen consumption, using an ergometer cycle or an outdoor walking. The studies reported improvements in cardiorespiratory function, lipid, hemodynamic and metabolic profile, body composition, and neuromuscular and cognitive capacity. This review presents characteristics and recommendations that technicians can follow when structuring, prescribing, and implementing CT programs to individuals with ID.

Effects of Baduanjin exercise on the physical function of middle-aged and elderly people: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

Chinese mind-body exercise-Baduanjin has received increasing attention for health promotion among middle-aged and older adults in China, but there is a lack of high-quality evidence on its effectiveness. This systematic review and meta-analysis was conducted to investigate the effects of Baduanjin on physical function in middle-aged and older adults.

METHODS

Seven electronic databases were searched for articles published before 22 June 2021 with the keywords Baduanjin exercise combined with physical-function-related outcomes. Risk of bias was assessed in the included studies, and data were analyzed using Review Manager software V5.3.

RESULTS

Fifteen articles, including 14 randomized controlled trials, were included in this study. The results of the meta-analysis showed that Baduanjin significantly improved muscle strength (grip strength: SMD = 0.63, 95% CI 0.22 to 1.04, p = 0.003), balance ability (timed up-and-go test score: MD = -2.21, 95% CI -3.91 to -0.51, p = 0.01; one-leg stand test score: MD = 3.75, 95% CI 1.96 to 5.55, p < 0.0001; Berg balance scale score: MD = 4.16, 95% CI 2.49 to 5.83, p < 0.00001; strengthening Romberg's test result: SMD = 1.02, 95% CI 0.17 to 1.86, p = 0.02); and cardiorespiratory fitness (diastolic blood pressure: MD = -3.62, 95% CI -3.95 to -3.30, p < 0.00001; resting heart rate: MD = -1.30, 95% CI -1.57 to -1.03, p < 0.00001; step test: MD = 4.25, 95% CI 0.76 to 7.74, p = 0.02). No adverse events were reported.

CONCLUSIONS

Baduanjin exercise may be an effective intervention to improve physical function in the middle-aged and elderly population. However, more RCTs with larger sample sizes and more rigorous research designs are needed in the future to confirm the results.

Physical Activity and Cardiorespiratory Fitness as Modulators of Health Outcomes: A Compelling Research-Based Case Presented to the Medical Community

The beneficial health effects and prognostic significance of regular moderate-to-vigorous physical activity (PA), increased cardiorespiratory fitness (CRF), or both are often underappreciated by the medical community and the patients they serve. Individuals with low CRF have higher annual health care costs, higher rates of surgical complications, and are two to three times more likely to die prematurely than their fitter counterparts when matched for risk factor profile or coronary calcium score. Increased levels of habitual PA before hospitalization for acute coronary syndromes are also associated with better short-term cardiovascular outcomes. Accordingly, this review examines these relations and the potential underlying mechanisms of benefit (eg, exercise preconditioning), with specific reference to the incidence of cardiovascular, cancer, and coronavirus diseases, and the prescriptive implications and exercise thresholds for optimizing health outcomes. To assess the evidence supporting or refuting the benefits of PA and CRF, we performed a literature search (PubMed) and critically reviewed the evidence to date. In aggregate, these data are presented in the context of clarifying the impact that regular PA and/or increased CRF have on preventing and treating chronic and infectious diseases, with reference to evidence-based exercise thresholds that the medical community can embrace and promote.

Cardiovascular exercise, learning, memory, and cytokines: Results of a ten-week randomized controlled training study in young adults

Physical exercise has been shown to enhance memory and to increase neuroplasticity. Rodent studies have revealed modulating effects of signaling molecules of the immune system (cytokines) on hippocampal plasticity and memory. Acute and chronic exercise have been both found to alter the number and function of immune cells. Thus, physical exercise might enhance neuroplasticity via an altered immune response. In this study we tested whether multiple repetitions of a vocabulary learning task combined with a bout of cardiovascular exercise enhances learning in humans and whether memory improvements correlated with acute exercise-induced cytokine changes. Data of 52 participants (20-40 years of age) who were randomly assigned to a cardiovascular exercise group (cycling) or a control group (stretching) were analyzed. During the 10-week treatment, participants completed 18 learning-exercise sessions. In each of these sessions, the vocabulary learning task was always performed immediately before exercising started. To assess acute exercise-induced changes in cytokine levels, blood sampling was performed at rest and immediately after exercising in two of the sessions. Learning success measured as increase in learning across all sessions and vocabulary retention four weeks after the treatment had ended did not differ between groups. The cycling group showed a relatively larger acute increase in IL-6, IL-1ra, IL-4, and IFN-γ compared to the stretching group. Exploratory analyses revealed significant positive associations between within-session learning and acute exercise-induced increases in IL-6 and IL-1ra in the cycling group only. These results suggest that the immune system may act as a mediator of exercise-induced cognitive benefits.

Durability is improved by both low and high intensity endurance training

Introduction: This is one of the first intervention studies to examine how low- (LIT) and high-intensity endurance training (HIT) affect durability, defined as 'time of onset and magnitude of deterioration in physiological-profiling characteristics over time during prolonged exercise'. Methods: Sedentary and recreationally active men (n = 16) and women (n = 19) completed either LIT (average weekly training time 6.8 ± 0.7 h) or HIT (1.6 ± 0.2 h) cycling for 10 weeks. Durability was analyzed before and after the training period from three factors during 3-h cycling at 48% of pretraining maximal oxygen uptake (VO_2max): 1) by the magnitude and 2) onset of drifts (i.e. gradual change in energy expenditure, heart rate, rate of perceived exertion, ventilation, left ventricular ejection time, and stroke volume), 3) by the 'physiological strain', defined to be the absolute responses of heart rate and its variability, lactate, and rate of perceived exertion. Results: When all three factors were averaged the durability was improved similarly (time x group p = 0.42) in both groups (LIT: p = 0.03, g = 0.49; HIT: p = 0.01, g = 0.62). In the LIT group, magnitude of average of drifts and their onset did not reach statistically significance level of p < 0.05 (magnitude: 7.7 ± 6.8% vs. 6.3 ± 6.0%, p = 0.09, g = 0.27; onset: 106 ± 57 min vs. 131 ± 59 min, p = 0.08, g = 0.58), while averaged physiological strain improved (p = 0.01, g = 0.60). In HIT, both magnitude and onset decreased (magnitude: 8.8 ± 7.9% vs. 5.4 ± 6.7%, p = 0.03, g = 0.49; onset: 108 ± 54 min vs. 137 ± 57 min, p = 0.03, g = 0.61), and physiological strain improved (p = 0.005, g = 0.78). VO_2max increased only after HIT (time x group p < 0.001, g = 1.51). Conclusion: Durability improved similarly by both LIT and HIT based on reduced physiological drifts, their postponed onsets, and changes in physiological strain. Despite durability enhanced among untrained people, a 10-week intervention did not alter drifts and their onsets in a large amount, even though it attenuated physiological strain.

Bayesian Analysis of the HR-VO2 Relationship during Cycling and Running in Males and Females

Professional organizations advise prescribing intensity of aerobic exercise using heart rate reserve (%HRR) which is presumed to have a 1:1 relationship with either maximal oxygen uptake (%VO₂max) or %VO₂ reserve (%VO₂R). Even though running and cycling are popular modes of training, these relationships have not been investigated in a group of males and females during both running and cycling. This study evaluated the %HRR-%VO₂max and %HRR-%VO₂R relationships in 41 college-aged males (n = 21) and females (n = 20) during treadmill running and cycling. Heart rate (HR) and VO₂ data were collected at rest and during maximal exercise tests on a treadmill and cycle ergometer. The HR and VO₂ data were analyzed using a Bayesian approach. Both the %HRR-%VO₂max and %HRR-%VO₂R relationships did not coincide with the line of identity in males and females in both treadmill running and cycling. %HRR was closer to %VO₂max than to %VO₂R. There were no significant differences in the intercepts of the %HRR-%VO₂max and %HRR-%VO₂R relationships between males and females during running or cycling, or between running and cycling in males or females. The credible intervals of the intercepts and slopes suggest interindividual variability in the HR-VO₂ relationship that would yield significant error in the prescription of intensity of aerobic exercise for an individual.

Physical activity, cardiorespiratory fitness, and cardiovascular health: A clinical practice statement of the American Society for Preventive Cardiology Part II: Physical activity, cardiorespiratory fitness, minimum and goal intensities for exercise training, prescriptive methods, and special patient populations

The prescription of exercise for individuals with and without cardiovascular disease (CVD) should be scientifically-based yet adapted to the patient. This scientific statement reviews the clinical and physiologic basis for the prescription of exercise, with specific reference to the volume of physical activity (PA) and level of cardiorespiratory fitness (CRF) that confer significant and optimal cardioprotective benefits. Recommendations are provided regarding the appropriate intensity, frequency, and duration of training; the concept of MET-minutes per week; critical components of the exercise session (warm-up, conditioning phase, cool-down); methodologies for establishing the training intensity, including oxygen uptake reserve (V̇O2R), target heart rate derivation and rating perceived exertion; minimum and goal intensities for exercise training; and, types of training activities, including resistance training, adjunctive lifestyle PA, marathon/triathlon training, and high-intensity interval training. In addition, we discuss the rationale for and value of exercise training programs for patients with peripheral artery disease, diabetes mellitus, and heart failure.

Experiencing good results promotes positive feelings to high-intensity exercise among young adults: A qualitative study

Introduction

From a public health perspective, it is important to gain more insight into how people can be motivated to maintain effective exercise routines. It is a common belief that moderate-intensity exercise is more pleasant and enjoyable than high-intensity training. This study aims to provide insight into (1) participants' expectations and preferences for training intensity prior to training, (2) how longer-term participation affect participants' experience of endurance training with continuous moderate-intensity training and high-intensity interval training.

Materials and methods

A total of 22 participants (14 women and eight men) between the ages of 21–30 volunteered for participation. Participants were randomized and divided into two equal groups. A total of 17 participants, nine women and eight men, completed the study. One group did moderate-intensity longer-lasting training and the other did high-intensity interval training. All participants completed three training sessions per week for 8 weeks. Semi-structured interviews were conducted with each participant before and after completing the training intervention. Data was analyzed using thematic analysis. This study is a part of a larger study evaluating and comparing the effects on endurance capacity of high-intensity interval training and moderate-intensity training. Physiological data are previously published.

Results

The results describe participants expectations prior to training, and how they experienced the actual training. The overall experience of training comprises several factors that work together. Both expectations and actual experiences (e.g., of physical pleasantness or unpleasantness, of positive or negative emotions, and of actual results from the training) contribute to the participants' overall experience of exercise.

Conclusion

The major finding is that improved physical fitness was a stronger motivator than feelings of pleasantness. Experiencing good results seemed to downplay feelings of unpleasantness and reinforce positive feelings toward exercise. Lack of results reinforce negative feelings toward exercise. Participants reported high-intensity exercise as more unpleasant and exhaustive, but the interval training group were more satisfied and experienced the training as more motivating.

Blood flow restriction accelerates aerobic training-induced adaptation of [Formula: see text] kinetics at the onset of moderate-intensity exercise

It is unclear whether blood flow restriction (BFR) accelerates the adaptation of the time constant (τ) of phase II oxygen uptake ([Formula: see text]) kinetics in the moderate-intensity exercise domain via moderate-intensity aerobic training. Therefore, healthy participants underwent moderate-intensity [45-60% [Formula: see text] Reserve] aerobic cycle training with or without BFR (BFR group, n = 9; CON group, n = 9) for 8 weeks to evaluate [Formula: see text] kinetics during moderate-intensity cycle exercise before (Pre) and after 4 (Mid) and 8 (Post) weeks of training. Both groups trained for 30 min, 3 days weekly. BFR was performed for 5 min every 10 min by applying cuffs to the upper thighs. The τ significantly decreased by Mid in the BFR group (23.7 ± 2.9 s [Pre], 15.3 ± 1.8 s [Mid], 15.5 ± 1.4 s [Post], P < 0.01) and by Post in the CON group (27.5 ± 2.0 s [Pre], 22.1 ± 0.7 s [Mid], 18.5 ± 1.9 s [Post], P < 0.01). Notably, the BFR group's τ was significantly lower than that of the CON group at Mid (P < 0.01) but not at Post. In conclusion, BFR accelerates the adaptation of the [Formula: see text] kinetics of phase II by moderate-intensity aerobic training.

Physical Activity in Renal Disease (PAIRED) and the effect on hypertension: a randomized controlled trial

INTRODUCTION

Exercise is an effective strategy for blood pressure (BP) reduction in the general population, but efficacy for the management of hypertension in CKD is not known. We evaluated the difference in 24-hour ambulatory systolic BP with exercise training in people with moderate to severe chronic kidney disease (CKD).

METHODS

Participants with an estimated glomerular filtration rate (eGFR) of 15-44 mL/min per 1.73m2 and SBP >120 mmHg were randomized to receive thrice weekly, moderate intensity aerobic-based exercise over 24 weeks, or usual care. Phase 1 included supervised in-center and home-based sessions for eight weeks. Phase 2 was 16 weeks of home-based sessions. BP, arterial stiffness, cardiorespiratory fitness, and markers of CV risk were analyzed using mixed linear regression.

RESULTS

We randomized 44 people; 36% were female, median age was 69 years, 55% had diabetes and the median eGFR was 28 mL/min per 1.73m2. Compared with usual care, there was no significant change in 24-ambulatory SBP at eight weeks 2.96 mmHg (95% CI -2.56, 8.49) or 24 weeks. Peak oxygen uptake improved by 1.9 mL/kg/min in the exercise group (95% CI 0.03, 3.79) at eight weeks with a trend toward higher BMI 1.84 kg/m2 (95% CI -0.10, 3.78) and fat free mass, but this was not sustained at 24 weeks. Markers of CV risk were unchanged.

CONCLUSIONS

Despite an improvement in VO2peak and body composition, we did not detect a change in 24-hour ambulatory systolic BP in people with moderate to severe chronic kidney disease.

Impact of a Preoperative Exercise Program on General Fitness in Patients Awaiting Bariatric Surgery: A Pilot Randomized Trial

Background

Evidence supports the association between exercise and outcomes following bariatric surgery. However, there is a lack of knowledge regarding the short-term benefits of preoperative exercise.

Objectives

The objective of this pilot study was to evaluate the feasibility and functional benefits of a 12-week preoperative exercise program in patients awaiting bariatric surgery. The primary aim was the six-minute walk test (6MWT). The secondary aim of this study included anthropometric measures, strength, and quality of life.

Methods

A total of 54 patients were enrolled in this pilot randomized controlled study. Of them, 29 patients received standard multidisciplinary preoperative care, while 25 patients participated in a 12-week supervised exercise program in addition to standard preoperative care consisting of strength and aerobic exercises three times per week in a fitness facility. The primary outcome was improvement in 6MWT. Secondary outcomes included other functional outcomes, quality of life, and anthropometric measures.

Results

Average attendance for the intervention group was 27.2 (75.6%) of 36 sessions. There was a mean improvement of 27 ± 10 meters in the intervention group compared with a reduction of 5 ± 10 meters in the control group (p = 0.003). Patients in the intervention group had significant improvement in all self-reported quality-of-life domains, particularly in the variables related to symptoms, hygiene, and emotions.

Conclusions

A 12-week preoperative exercise intervention was feasible and showed association with a statistically significant improvement in 6MWT and quality-of-life measures in patients awaiting bariatric surgery. The results of this study will inform sample size calculations and recruitment planning for a future study that will assess the longer-term benefits of a pre-surgical fitness intervention.

Relationships of Changes in Physical Activity and Sedentary Behavior With Changes in Physical Fitness and Cardiometabolic Risk Profile in Individuals With Type 2 Diabetes: The Italian Diabetes and Exercise Study 2 (IDES_2)

OBJECTIVE

In the Italian Diabetes and Exercise Study_2 (IDES_2), behavioral counseling promoted a sustained increase in physical activity (PA) volume (+3.3 MET h ⋅ week-1), moderate- to vigorous-intensity PA (MVPA) (+6.4 min ⋅ day-1), and light-intensity PA (LPA) (+0.8 h ⋅ day-1) and decrease in sedentary time (SED-time) (-0.8 h ⋅ day-1). Here, we investigated the relationships of changes in PA/SED-time with changes in physical fitness and cardiometabolic risk profile in individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this 3-year randomized clinical trial, 300 physically inactive and sedentary patients were randomized 1:1 to receive 1-month theoretical and practical counseling once a year or standard care. Changes in physical fitness and cardiovascular risk factors/scores according to quartiles of accelerometer-measured changes in PA/SED-time were assessed, together with univariate and multivariable associations between these parameters, in the whole cohort and by study arm.

RESULTS

Physical fitness increased and HbA1c and coronary heart disease 10-year risk scores decreased with quartiles of MVPA and SED-time change. In quartile IV of MVPA increase and SED-time decrease, cardiorespiratory fitness increased by 5.23 and 4.49 mL ⋅ min-1 ⋅ kg-1 and HbA1c decreased by 0.73 and 0.85%, respectively. Univariate correlations confirmed these relationships, and mean changes in both MPVA and SED-time predicted changes in physical fitness and cardiovascular risk factors/scores independently of one another and of other confounders. Similar findings were observed with LPA and PA volume and in each group separately.

CONCLUSIONS

Even modest increments in MVPA may have a clinically meaningful impact, and reallocating SED-time to LPA may also contribute to improved outcomes, possibly by increasing total energy expenditure.

Background Inactivity Blunts Metabolic Adaptations to Intense Short-Term Training

PURPOSE

This study determined if the level of background physical inactivity (steps per day) influences the acute and short-term adaptations to intense aerobic training.

METHODS

Sixteen untrained participants (23.6 ± 1.7 yr) completed intense (80%-90% V˙O2peak) short-term training (5 bouts of exercise over 9 d) while taking either 4767 ± 377 steps per day (n = 8; low step) or 16,048 ± 725 steps per day (n = 8; high step). At baseline and after 1 d of acute exercise and then after the short-term training (posttraining), resting metabolic responses to a high-fat meal (i.e., plasma triglyceride concentration and fat oxidation) were assessed during a 6-h high-fat tolerance test. In addition, responses during submaximal exercise were recorded both before and after training during 15 min of cycling (~79% of pretraining V˙O2peak).

RESULTS

High step displayed a reduced incremental area under the curve for postprandial plasma triglyceride concentrations by 31% after acute exercise and by 27% after short-term training compared with baseline (P < 0.05). This was accompanied by increased whole-body fat oxidation (24% and 19%; P < 0.05). Furthermore, stress during submaximal exercise as reflected by heart rate, blood lactate, and deoxygenated hemoglobin were all reduced in high step (P < 0.05), indicating classic training responses. Despite completing the same training regimen, low step showed no significant improvements in postprandial fat metabolism or any markers of stress during submaximal exercise after training (P > 0.05). However, the two groups showed a similar 7% increase in V˙O2peak (P < 0.05).

CONCLUSION

When completing an intense short-term exercise training program, decreasing daily background steps from 16,000 to approximately 5000 steps per day blunts some of the classic cardiometabolic adaptations to training. The blunting might be more pronounced regarding metabolic factors (i.e., fat oxidation and blood lactate concentration) compared with cardiovascular factors (i.e., V˙O2peak).

Does aerobic exercise benefit persons with tetraplegia from spinal cord injury? A systematic review

CONTEXT

This review synthesizes the findings of previous research studies on the cardiovascular and metabolic benefits of aerobic exercise for individuals with tetraplegia secondary to spinal cord injury. They are often less active due to muscular paralysis, sensory loss, and sympathetic nervous system dysfunction that result from injury. Consequently, these persons are at higher risk for exercise intolerance and secondary health conditions.

OBJECTIVE

To evaluate the evidence concerning efficacy of aerobic exercise training for improving health and exercise performance in persons with tetraplegia from cervical injury.

METHODS

The search engines PubMed and Google Scholar were used to locate published research. The final 75 papers were selected on the basis of inclusion criteria. The studies were then rank-ordered using Physiotherapy Evidence Database.

RESULTS

Studies combining individuals with tetraplegia and paraplegia show that voluntary arm-crank training can increase mean peak power output by 33%. Functional electrical stimulation leg cycling was shown to induce higher peak cardiac output and stroke volume than arm-crank exercise. A range of peak oxygen uptake (VO_2peak) values have been reported (0.57-1.32 L/min). Both VO_2peak and cardiac output may be enhanced via increased muscle pump in the legs and venous return to the heart. Hybrid exercise (arm-crank and functional electrical stimulation leg cycling) can result in greater peak oxygen uptake and cardiovascular responses.

CONCLUSION

Evidence gathered from this systematic review of literature is inconclusive due to the lack of research focusing on those with tetraplegia. Higher power studies (level 1-3) are needed with the focus on those with tetraplegia.

The central role of mitochondrial fitness on antiviral defenses: An advocacy for physical activity during the COVID-19 pandemic

Mitochondria are central regulators of cellular metabolism, most known for their role in energy production. They can be "enhanced" by physical activity (including exercise), which increases their integrity, efficiency and dynamic adaptation to stressors, in short "mitochondrial fitness". Mitochondrial fitness is closely associated with cardiorespiratory fitness and physical activity. Given the importance of mitochondria in immune functions, it is thus not surprising that cardiorespiratory fitness is also an integral determinant of the antiviral host defense and vulnerability to infection. Here, we first briefly review the role of physical activity in viral infections. We then summarize mitochondrial functions that are relevant for the antiviral immune response with a particular focus on the current Coronavirus Disease (COVID-19) pandemic and on innate immune function. Finally, the modulation of mitochondrial and cardiorespiratory fitness by physical activity, aging and the chronic diseases that represent the most common comorbidities of COVID-19 is discussed. We conclude that a high mitochondrial - and related cardiorespiratory - fitness should be considered as protective factors for viral infections, including COVID-19. This assumption is corroborated by reduced mitochondrial fitness in many established risk factors of COVID-19, like age, various chronic diseases or obesity. We argue for regular analysis of the cardiorespiratory fitness of COVID-19 patients and the promotion of physical activity - with all its associated health benefits - as preventive measures against viral infection.

Targeting Diet Quality at the Workplace: Influence on Cardiometabolic Risk

The American Heart Association criteria for cardiovascular health include overall diet quality (DQ). The present study evaluated the effect of a workplace health promotion program targeting DQ and physical activity on features of cardiometabolic risk (CMR). Before and after the 3-month intervention, 2260 employees (1462 men and 798 women) completed a health and fitness evaluation including assessment of DQ using a validated food-based questionnaire. After the 3-month lifestyle modification program, DQ increased significantly in both sexes (p < 0.0001) as well as physical activity level (p < 0.0001). A reduction in waist circumference (p < 0.0001) and improved lipid levels were also observed. Significant associations were found between changes in DQ index and changes in CMR variables in both men (standardized regression coefficients ranged from −0.19 (95% confidence interval: −0.26 to −0.12) to −0.29 (95% confidence interval: −0.34 to −0.25)) and women (standardized regression coefficients ranged from −0.18 (95% confidence interval: −0.25 to −0.11) to −0.27 (95% confidence interval: −0.41 to −0.13)). Multiple linear regression analyses showed a significant contribution of changes in the DQ index to the variation in some CMR variables, independent from changes in physical activity level and cardiorespiratory fitness. This study provides evidence that targeting DQ at the workplace is relevant to improve cardiometabolic health.

High-intensity exergaming for improved cardiorespiratory fitness: A randomised, controlled trial

ABSTRACTExergaming has been proposed as a promising alternative to traditional endurance training since many experience exergaming as more enjoyable. Therefore, the aim of this trial was to determine the exergaming-induced effect on cardiorespiratory fitness. This parallel-group randomised controlled trial, investigated the effects of regular exergaming among healthy adults (aged ≥ 18 years) who were not endurance-trained. Participants allocated to the exergaming group (n = 13) used the Playpulse exergaming platform for a minimum of 45 min twice weekly for eight weeks, whereas the control group (n = 17) received no intervention. The primary outcome measure was the between-group difference in peak oxygen uptake (V̇O_2peak) after the intervention. V̇O_2peak increased significantly from baseline (43.9 [SD 7.0]) to after the intervention (45.3 [SD 8.2] mL kg^-1 min^-1) in the exergaming group, compared to the control group (42.4 [SD 7.0] to 42.0 [SD 5.7] mL·kg^-1·min^-1) with a between-group difference of 2.1 mL kg^-1 min^-1 (95% CI: 0.2-4.1; p = 0.04). The average score on the Feeling Scale reported during exergaming was 3.4 (95% CI 3.2-3.6), with 3 being "good" and 5 "very good" and was not related to the participants' exergaming skills. There were no adverse events during this trial. Two weekly sessions using the Playpulse exergaming platform can improve V̇O_2peak. This finding suggests that exergaming can be an efficient form of endurance training. Furthermore, our findings indicate that participants' enjoyed exergaming irrespective of exergaming skills.Trial registration: ClinicalTrials.gov identifier: NCT04112329..

Estimation of cardiovascular drift through ear temperature during prolonged steady-state cycling: a study protocol

Introduction

The measurement of heart rate is commonly used to estimate exercise intensity. However, during endurance performance, the relationship between heart rate and oxygen consumption may be compromised by cardiovascular drift. This physiological phenomenon mainly consists of a time-dependent increase in heart rate and decrease in systolic volume and may lead to overestimate absolute exercise intensity in prediction models based on heart rate. Previous research has established that cardiovascular drift is correlated to the increase in core body temperature during prolonged exercise. Therefore, monitoring body temperature during exercise may allow to quantify the increase in heart rate attributable to cardiovascular drift and to improve the estimate of absolute exercise intensity. Monitoring core body temperature during exercise may be invasive or inappropriate, but the external auditory canal is an easily accessible alternative site for temperature measurement.

Methods and analysis

This study aims to assess the degree of correlation between trends in heart rate and in ear temperature during 120 min of steady-state cycling with intensity of 59% of heart rate reserve in a thermally neutral indoor environment. Ear temperature will be monitored both at the external auditory canal level with a contact probe and at the tympanic level with a professional infrared thermometer.

Ethics and dissemination

The study protocol was approved by an independent ethics committee. The results will be submitted for publication in academic journals and disseminated to stakeholders through summary documents and information meetings.

Feasibility and adherence to moderate intensity cardiovascular fitness training following stroke: a pilot randomized controlled trial

BACKGROUND

Stroke is a leading cause of disability worldwide and the cardiovascular fitness levels of stroke survivors are diminished to an extent that impairs functioning and activities of daily living performance. While cardiovascular training seems an empirically appropriate intervention, the optimal dosage and intensity of cardiovascular training in stroke survivors remains unclear. The aim was to determine the safety and feasibility of moderate-intensity cardiovascular training following stroke, including measurement of adherence to training.

METHODS

A pilot, prospective, patient- and assessor-blinded randomised controlled trial conducted in a tertiary, metropolitan hospital-based community rehabilitation centre. Eligibility criteria included ambulant (> 100 m), 6 weeks-12 months post stroke. Moderate-intensity fitness training or control (low-intensity) exercise was offered biweekly for 12 weeks. Outcome measures included adverse events, peak oxygen uptake (VO₂), functional exercise capacity (6-Minute Walk Test, 10-m Walk Test) and health-related quality of life (Short Form-36) and mood (Patient Health Questionnaire, PHQ9).

RESULTS

Feasibility: Seventy-one (50%) of 141 screened participants were eligible (29% did not agree to participate). Twenty participants (10 intervention, 10 control) were recruited. The median (%; IQR) supervised sessions was 19.5 (81%; 12, 20); and 20 (83%; 19, 22) in the intervention and control groups, respectively. Progression of duration and intensity was limited; mean of 10 sessions to achieve target duration (30 min). There were no adverse events. Baseline peak oxygen uptake (VO₂) levels were low (15.94 ml/kg/min). Significant improvements in VO₂ peak in both groups were observed (p < 0.05). Although there were no significant between-group differences, this feasibility trial was not powered to detect change.

CONCLUSIONS

Moderate-intensity fitness training was safe but achievement of target duration and intensity was challenging for stroke survivors. A definitive adequately-powered randomised trial is required. Alternative fitness training protocols may need to be explored.

TRIAL REGISTRATION

The trial protocol was prospectively registered on the Australian New Zealand Clinical Trials Registry ( ACTRN 12613000822785 ) on 25/07/2013.

The longitudinal effect of leisure time physical activity on reduced depressive symptoms: The ARIRANG Study

BACKGROUND

Depression is a serious mental condition and physical activity is known to be effective in alleviating it. This study for rural residents of South Korea investigated whether meeting the recommended amount of physical activity during leisure time (LTPA) can reduce the depressive symptoms.

METHODS

A prospective study was conducted with 5,178 participants aged 20 years and over, and we analyzed 1,888 participants excluding those diagnosed with depression at baseline and those with insufficient data after an average of 5.3 years of follow-up. LTPA was quantified by the MET (metabolic equivalent of task) and categorized according to whether the recommended physical activity was met (0, 0.1 to < 7.5, ≥ 7.5 MET h/wk). The relationship with depressive symptoms (CES-D ≥ 41) was generated by adjusted relative risks (RRs) and 95% CIs through multivariate logistic regression.

RESULTS

During the followed-up, 100 (5.3%) participants developed depressive symptoms. Compared to the incidence of depressive symptoms in those who did not perform any LTPA (6.8%), it was significantly lower when the recommended physical activity criteria were met by combining moderate intensity (MET 3 to 6) and vigorous intensity (MET ≥ 6) exercise (3.3%). We observed a 43.7% lower risk of depressive symptoms among those performing more than the recommended minimum (RR, 0.563 [95% CI, 0.341-0.930]) than those who had no LTPA.

LIMITATIONS

This study did not address psychosocial factors, and physical activities in daily life and the occupational environment were not considered.

CONCLUSIONS

Performing adequate LTPA might be advisable to alleviate depressive symptoms.

Association of Physical Activity Intensity With Mortality: A National Cohort Study of 403 681 US Adults

IMPORTANCE

It is unclear whether, for the same amount of total physical activity, a higher proportion of vigorous physical activity (VPA) to total physical activity is associated with a greater reduction in mortality.

OBJECTIVE

To examine the association of the proportion of VPA to total physical activity (defined as moderate to vigorous physical activity [MVPA]) with all-cause mortality, cardiovascular disease mortality, and cancer mortality.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 403 681 adults from the National Health Interview Survey 1997-2013 who provided data on self-reported physical activity and were linked to the National Death Index records through December 31, 2015. Statistical analysis was performed from May 15, 2018, to August 15, 2020.

EXPOSURES

Proportion of VPA to total physical activity among participants performing any MVPA.

MAIN OUTCOMES AND MEASURES

All-cause mortality, cardiovascular disease mortality, and cancer mortality. Cox proportional hazards regression models were performed to estimate hazard ratios (HRs) and 95% CIs, adjusted for sociodemographic characteristics, lifestyle risk factors, and total physical activity.

RESULT

Among the 403 681 individuals (225 569 women [51.7%]; mean [SD] age, 42.8 [16.3] years) in the study, during a median 10.1 years (interquartile range, 5.4-14.6 years) of follow-up (407.3 million person-years), 36 861 deaths occurred. Mutually adjusted models considering the recommendations of moderate physical activity (MPA; 150-299 vs 0 minutes per week) and VPA (≥75-149 vs 0 minutes per week) showed similar associations for all-cause mortality (MPA: HR, 0.83; 95% CI, 0.80-0.87; and VPA: HR, 0.80; 95% CI, 0.76-0.84) and cardiovascular disease mortality (MPA: HR, 0.75; 95% CI, 0.68-0.83; and VPA: HR, 0.79; 95% CI, 0.70-0.91). For the same contrasts, VPA (HR, 0.89; 95% CI, 0.80-0.99) showed a stronger inverse association with cancer mortality compared with MPA (HR, 0.94; 95% CI, 0.86-1.02). Among participants performing any MVPA, a higher proportion of VPA to total physical activity was associated with lower all-cause mortality but not with cardiovascular disease and cancer mortality. For instance, compared with participants with 0% of VPA (no vigorous activity), participants performing greater than 50% to 75% of VPA to total physical activity had a 17% lower all-cause mortality (hazard ratio, 0.83; 95% CI, 0.78-0.88), independent of total MVPA. The inverse association between proportion of VPA to total physical activity and all-cause mortality was consistent across sociodemographic characteristics, lifestyle risk factors, and chronic conditions at baseline.

CONCLUSIONS AND RELEVANCE

This study suggests that, for the same volume of MVPA, a higher proportion of VPA to total physical activity was associated with lower all-cause mortality. Clinicians and public health interventions should recommend 150 minutes or more per week of MVPA but also advise on the potential benefits associated with VPA to maximize population health.

Novel CPET Reference Values in Healthy Adults: Associations with Physical Activity

PURPOSE

Cardiopulmonary exercise testing (CPET) is an important measurement in clinical practice, and its primary outcome, maximal oxygen uptake (V˙O2peak), is inversely associated with morbidity and mortality. The purposes of this study are to provide CPET reference values for maximal and submaximal parameters across the adult age spectrum of a healthy European cohort, to compare V˙O2peak values with other reference data sets, and to analyze the associations between physical activity (PA) levels and CPET parameters.

METHODS

In this cross-sectional study, we prospectively recruited 502 participants (47% female) from 20 to 90 yr old. The subjects performed a CPET on a cycle ergometer using a ramp protocol. PA was objectively and continuously measured over 14 d using a triaxial accelerometer. Quantile curves were calculated for CPET parameters. To investigate the associations between CPET parameters and PA levels, linear regression analysis was performed.

RESULTS

V˙O2peak values observed in the group of 20-29 yr were 46.6 ± 7.9 and 39.3 ± 6.5 mL·kg⋅min for males and females, respectively. On average, each age category (10-yr increments) showed a 10% lower V˙O2peak relative to the next younger age category. V˙O2peak values of previous studies were on average 7.5 mL·kg⋅min (20%) lower for males and 6.5 mL·kg⋅min (21%) lower for females. There was strong evidence supporting a positive association between the V˙O2peak (mL·kg⋅min) and the level of habitual PA performed at vigorous PA (estimate, 0.26; P < 0.001].

CONCLUSION

Maximal and submaximal CPET reference values over a large age range are novel, and differences to other studies are clinically highly relevant. Objectively measured vigorous-intensity PA showed a strong positive association with higher V˙O2peak and other performance-related CPET parameters, supporting the implementation of higher-intensity aerobic exercise in health promotion.

Interval training during concurrent training optimizes cardiorespiratory adaptations in women

Abstract This study compared the effects of using continuous and interval aerobic exercise during concurrent training on cardiorespiratory adaptations in women. Thirty-two participants were randomly assigned into one of the following groups: continuous running and resistance training (C-RUN, n = 10), interval running and resistance training (I-RUN, n = 11), or control group that performed resistance training only (RT, n = 11). Each group trained twice a week during 11 weeks. Oxygen uptake corresponding to the first ventilatory threshold (VO2VT1), second ventilatory threshold (VO2VT2) and maximal effort (VO2max) was measured in a maximal incremental test performed before and after training. Significant increases in VO2VT1, VO2VT2 and VO2max were observed in all training groups. VO2VT2 and VO2max presented time-group interactions, indicating that the magnitude of the increase in these variables was dependent on the training group (VO2VT2: C-Run = 6.6%, I-Run = 15.7%, RT = 1.7%; VO2max: C-Run = 7.2%, I-Run = 14.3%, RT = 2.7%). The effect size observed for post-training values comparing C-RUN and RT groups was d = 0.566 for VO2VT2 and d = 0.442 for VO2max. On the other hand, values of d = 0.949 for VO2VT2 and d = 1.189 for VO2max were verified between I-RUN and RT groups. In conclusion, the use of continuous and interval aerobic exercise during concurrent training improved different cardiorespiratory parameters in women, but in a greater magnitude when interval aerobic exercise was performed simultaneously to resistance training.

The impact of low-intensity blood flow restriction endurance training on aerobic capacity, hemodynamics, and arterial stiffness

BACKGROUND

The aim of this study was to determine the effects of short-term low-intensity blood flow restriction (BFR) endurance training (ET) programs on measures of aerobic capacity, hemodynamics, and arterial stiffness in healthy young males.

METHODS

Thirty-nine healthy young recreationally active males participated in this short-term training study. They were randomly assigned to a high-intensity (HI; N.=11; trained at 60-70% of VO<inf>2</inf> reserve [VO<inf>2</inf>R]), low-intensity (LI; N.=8; trained at 30-40% of VO<inf>2</inf>R), low-intensity with BFR (LI-BFR; N.=10; trained at 30-40% of VO<inf>2</inf>R with BFR) or a non-exercising control group (N.=10). The exercising subjects completed a 6-wk training protocol on a treadmill. Assessment of aerobic capacity (VO<inf>2max</inf>), hemodynamics and arterial stiffness were done before and after training.

RESULTS

Statistical analyses revealed a significant condition main effect (P<0.05) for VO<inf>2max</inf>, indicating significant increase (P<0.05) in VO<inf>2max</inf> in LI-BFR group compared to control. There were no significant changes for resting heart rate (RHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), carotid-radial pulse wave velocity (PWV), and carotid-femoral PWV (P>0.05). However, femoral-tibial PWV decreased significantly (P<0.05) from baseline to post-training.

CONCLUSIONS

The results indicate that the application of BFR during ET may cause faster and/or greater adaptations in one or more physiological systems resulting in improved cardiorespiratory fitness.

Do vigorous-intensity and moderate-intensity physical activities reduce mortality to the same extent? A systematic review and meta-analysis

Objective

To examine whether vigorous-intensity physical activity confers additional reductions on all-cause and cause-specific mortality compared with moderate-intensity physical activity.

Design

A systematic review (registered in PROSPERO CRD42019138995) and meta-analysis.

Data sources

Three electronic databases up to April 14 2020.

Eligibility criteria

Inclusion criteria were prospective studies that contained information about (1) moderate-intensity (3–5.9 metabolic equivalent tasks (METs)) and vigorous-intensity (≥6 METs) physical activities and (2) all-cause and/or cause-specific mortality. Exclusion criteria were prospective studies that (1) exclusively recruited diseased patients (eg, hypertensive patients and diabetics) or (2) did not account for total physical activity in their multivariable models (3) or did not adjust or exclude individuals with comorbidities at baseline or (4) used physically inactive participants as reference group.

Results

Five studies (seven cohorts using sex-specific results) were pooled into a meta-analysis. For all-cause mortality and controlling by total physical activity, vigorous-intensity physical activity (vs moderate) was not associated with a larger reduction in mortality (HR 0.95, 95% CI 0.83 to 1.09). After the exclusion of one study judged with critical risk of bias (Risk Of Bias in Non randomized Studies, ROBINS tool) from meta-analysis, results remained similar (HR 0.98, 95% CI 0.85 to 1.12). Due to the limited number of studies, meta-analyses for cancer and cardiovascular mortality were not performed.

Conclusions

Prospective studies suggest that, for the same total physical activity, both vigorous-intensity and moderate-intensity physical activities reduce all-cause mortality to the same extent. However, absence of evidence must not be interpreted as evidence of absence due to the existing methodological flaws in the literature.

Prenatal Exercise and Cardiorespiratory Health and Fitness: A Meta-analysis

PURPOSE

This study aimed to examine the influence of prenatal exercise on maternal cardiorespiratory health and fitness during pregnancy.

METHODS

Online databases were searched up to February 25, 2019. Studies of randomized controlled trials (RCTs) were eligible, which contained information on the relevant population (pregnant women), intervention (subjective or objective measures of frequency, intensity, duration, volume, or type of exercise), comparator (no exercise intervention), and outcomes (maternal cardiorespiratory fitness, including V˙O2max, submaximal V˙O2, V˙O2 at anaerobic threshold, and cardiorespiratory health, including resting heart rate, and resting systolic and diastolic blood pressures during pregnancy).

RESULTS

From 2699 unique citations, 26 RCTs (N = 2292 women) were included. Of these, one study reported measured V˙O2max, seven reported predicted V˙O2max, three reported submaximal V˙O2, and two studies reported VO2AT. "Low"- to "high"-certainty evidence revealed that exercise was associated with improved predicted/measured V˙O2max (5 RCTs, n = 430; mean difference [MD], 2.77 mL·kg·min; 95% confidence interval [CI], 0.32 to 5.21 mL·kg·min; I = 69%), reduced resting heart rate (9 RCTs, n = 637; MD, -1.71 bpm; 95% CI, -3.24 to -0.19 bpm; I = 13%), resting systolic blood pressure (16 RCTs, n = 1672; MD, -2.11 mm Hg; 95% CI, -3.71 to -0.51 mm Hg; I = 69%), and diastolic blood pressure (15 RCTs, n = 1624; MD, -1.77 mm Hg; 95% CI, -2.90 to -0.64 mm Hg; I = 60%).

CONCLUSION

Prenatal exercise interventions improve maternal predicted/measured V˙O2max and reduce resting heart rate and blood pressure. This review highlights the need for additional high-quality studies of cardiorespiratory fitness (namely, V˙O2max and V˙O2 peak) in pregnancy.PROSPERO registration number: CRD42019131249.

The Relation between Domain-Specific Physical Behaviour and Cardiorespiratory Fitness: A Cross-Sectional Compositional Data Analysis on the Physical Activity Health Paradox Using Accelerometer-Assessed Data

In contrast to leisure time physical activity (LTPA), occupational physical activity (OPA) does not have similar beneficial health effects. These differential health effects might be explained by dissimilar effects of LTPA and OPA on cardiorespiratory fitness (CRF). This study investigated cross-sectional associations between different physical behaviours during both work and leisure time and CRF by using a Compositional Data Analysis approach. Physical behaviours were assessed by two accelerometers among 309 workers with various manual jobs. During work time, more sedentary behaviour (SB) was associated with higher CRF when compared relatively to time spent on other work behaviours, while more SB during leisure time was associated with lower CRF when compared to other leisure time behaviours. Reallocating more time to moderate-to-vigorous physical activity (MVPA) from the other behaviours within leisure time was positively associated with CRF, which was not the case for MVPA during work. The results of our study are in line with the physical activity health paradox and we call for further study on the interaction between LTPA and OPA by implementing device-worn measures in a longitudinal design. Our results highlight the need for recommendations to take into account the different effects of OPA and LTPA on CRF.

Can Gaming Get You Fit?

Rationale

Exergaming may be a viable alternative to more traditional exercise. As high-intensity exercise can provide substantial health benefits, the purpose of this study was to investigate the long-term effectiveness of providing inactive adults with access to a high-intensity exergaming platform.

Methods

In this study, 52 inactive adults (<150 min of exercise per week), aged 18 years or older, were randomized (1:1) into an exergaming (N = 27) or a control group (N = 25). Exergaming participants were given access to the Playpulse exergaming platform for 6 months, where they decided how frequently they wanted to use the platform. The primary outcome measure, analyzed with a mixed model, was peak oxygen uptake (V̇O_2peak). Secondary outcomes included body composition, blood pressure, and blood markers of cardiometabolic health.

Results

Mean V̇O_2peak at 6 months was 42.3 (SD 7.0) mL⋅kg⁻¹⋅min⁻¹ and 41.9 (SD 7.4) mL⋅kg⁻¹⋅min⁻¹ for the exergaming and control group, respectively with no significant between-group differences (-0.7, 95% CI -2.7 to 1.3, P = 0.49). Apart from increased moderate-intensity physical activity in the exergaming group at 3 months (21.9 min⋅day⁻¹, 95% CI: 2.2 to 41.5, P = 0.03) compared to the control group, there were no significant between-group differences for any outcome at either 3 or 6 months. On average, participants in the exergaming group performed 12 (SD 13) exergaming sessions with an average heart rate of 74.5 (SD 7.5)% of maximum heart rate, throughout the intervention.

Conclusion

Due to low exergaming frequency over the 6-month intervention, exergaming participants showed no significant health benefits compared to control. Our study indicates that although the Playpulse exergaming platform is found enjoyable, this is not enough to motivate inactive adults to regularly engage in exercise and thereby improve health.

Clinical Trial Registration

www.clinicaltrials.gov, identifier NCT03513380.

Novel stretching and strength-building exercise recommendations for computer-based workers during the COVID-19 quarantine

BACKGROUND

Prolonged home stays due to the COVID-19 quarantine can increase the use of computers and other technologies that may lead to significant reduction in activity, contributing to musculoskeletal problems, anxiety and depression.

OBJECTIVE

The aim of this study was to develop a novel multicomponent exercise program for individuals who work with computers during the COVID-19 quarantine.

METHODS

Researchers collaborating cross-institutionally and cross-nationally performed a careful literature search for exercise and stretching regiments with particular attention to methodologies that can be applied during the lockdown in the wake of the COVID-19 pandemic. Methodologies were then compiled and truncated for ease of use for the computer-based office worker during the COVID-19 pandemic quarantine.

RESULTS

The resulting program is broken down into three categories: aerobic, strengthening and stretching components. Each component can then be further modified to meet the frequency, intensity, time and type (FITT) specifications for the participant.

CONCLUSIONS

We present a novel, evidence-based strategy for functional fitness for office workers who have remained home-bound during the COVID-19 pandemic quarantine. Further research should seek to validate the efficacy of the proposed protocol.

Exercise and inflammation

Based on current knowledge deriving from studies in animals and humans (the general population and patients with non-communicable diseases), there is biological plausibility that exercise may have anti-inflammatory effects. This may be particularly important for patients with chronic inflammatory rheumatic and musculoskeletal diseases (RMDs). The present review discusses the current state-of-the-art on exercise and inflammation, explores how exercise can moderate inflammation-dependent RMD outcomes and the most prevalent systemic manifestations and addresses the relationship between the dosage (particularly the intensity) of exercise and inflammation. We conclude that present data support potential beneficial effects of exercise on inflammation, however, the evidence specifically in RMDs is limited and inconclusive. More targeted research is required to elucidate the effects of exercise on inflammation in the context of RMDs.

Type of Exercise Training and Training Methods

There is general agreement that exercise training leads to functional, morphological, and metabolic adaptations of different biological systems, thereby increasing overall physical performance and promoting good health. Thus, an active lifestyle is propagated in all age groups. However, not every exercise routine or workout is suitable for everyone. Inappropriate training can also pose risks, and too low or too high training intensity or volume often does not lead to the expected success. To ensure significant benefits, specific principles and strategies need to be considered and accustomed to the individual.This chapter summarizes the key exercise variables and training principles to consider when developing a training program to improve or maintain performance and health. In addition, the various steps for creating an individual training program are described, and an overview of the different training methods and training strategies is given.

The effects of aerobic training on the CD4 cells, VO2max, and metabolic parameters in HIV-infected patients: a meta-analysis of randomized controlled trials

INTRODUCTION

To our knowledge, there are no systematic review study with meta-analysis that investigated the influence of training variables on specific outcomes (CD4 cell counts) addressed aerobic training (AT) for HIV+ patients. In this sense, the purpose of this study was to perform a systematic review with meta-analysis of randomized controlled trials on AT in HIV+ patients and to analyze the influence of AT modulating variables on the CD4 cells, VO2max, and metabolic parameters.

EVIDENCE ACQUISITION

Searches were performed in the databases PubMed, ISI Web of Knowledge, SportDiscus, Lilacs, Science Direct, and Scielo.

EVIDENCE SYNTHESIS

Twelve studies involving 438 subjects (78.2% male) were included. Overall, the sample was sedentary (pre-training VO2max of 30.5 mL.kg-1.min-1) with a mean time of virus infection of 66.9 months and mean number of CD4 cells of 467.8 cells/mm3. AT increased the VO2max (ES=1050 [0.455 to 1.64]; P<0.001) and CD4 cell count (ES=0.402 [0.203 to 0.601]; P<0.001). AT for 8-12 weeks appears to be sufficient to increase VO2max, and the highest gains are associated with patients who present higher initial CD4 cell values. There was no difference to metabolic parameters.

CONCLUSIONS

AT did not change the metabolic parameters, but it was AT is able to promote a greater magnitude of improvement in VO2max in the initial weeks of training and a greater increase in the number of CD4 cells in patients who present a better immune condition prior to training.

Aerobic Training and Mobilization Early Post-stroke: Cautions and Considerations

Knowledge gaps exist in how we implement aerobic exercise programs during the early phases post-stroke. Therefore, the objective of this review was to provide evidence-based guidelines for pre-participation screening, mobilization, and aerobic exercise training in the hyper-acute and acute phases post-stroke. In reviewing the literature to determine safe timelines of when to initiate exercise and mobilization we considered the following factors: arterial blood pressure dysregulation, cardiac complications, blood-brain barrier disruption, hemorrhagic stroke transformation, and ischemic penumbra viability. These stroke-related impairments could intensify with inappropriate mobilization/aerobic exercise, hence we deemed the integrity of cerebral autoregulation to be an essential physiological consideration to protect the brain when progressing exercise intensity. Pre-participation screening criteria are proposed and countermeasures to protect the brain from potentially adverse circulatory effects before, during, and following mobilization/exercise sessions are introduced. For example, prolonged periods of standing and static postures before and after mobilization/aerobic exercise may elicit blood pooling and/or trigger coagulation cascades and/or cerebral hypoperfusion. Countermeasures such as avoiding prolonged standing or incorporating periodic lower limb movement to activate the venous muscle pump could counteract blood pooling after an exercise session, minimize activation of the coagulation cascade, and mitigate potential cerebral hypoperfusion. We discuss patient safety in light of the complex nature of stroke presentations (i.e., type, severity, and etiology), medical history, comorbidities such as diabetes, cardiac manifestations, medications, and complications such as anemia and dehydration. The guidelines are easily incorporated into the care model, are low-risk, and use minimal resources. These and other strategies represent opportunities for improving the safety of the activity regimen offered to those in the early phases post-stroke. The timeline for initiating and progressing exercise/mobilization parameters are contingent on recovery stages both from neurobiological and cardiovascular perspectives, which to this point have not been specifically considered in practice. This review includes tailored exercise and mobilization prescription strategies and precautions that are not resource intensive and prioritize safety in stroke recovery.