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

Pilates Method Improves Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis

Cardiorespiratory fitness has been postulated as an independent predictor of several chronic diseases. We aimed to estimate the effect of Pilates on improving cardiorespiratory fitness and to explore whether this effect could be modified by a participant's health condition or by baseline VO2 max levels. We searched databases from inception to September 2019. Data were pooled using a random effects model. The Cochrane risk of bias (RoB 2.0) tool and the Quality Assessment Tool for Quantitative Studies were performed. The primary outcome was cardiorespiratory fitness measured by VO2 max. The search identified 527 potential studies of which 10 studies were included in the systematic review and 9 in the meta-analysis. The meta-analysis showed that Pilates increased VO2 max, with an effect size (ES) = 0.57 (95% CI: 0.15-1; I2 = 63.5%, p = 0.018) for the Pilates group vs. the control and ES = 0.51 (95% CI: 0.26-0.76; I2 = 67%, p = 0.002) for Pilates pre-post effect. The estimates of the pooled ES were similar in both sensitivity and subgroup analyses; however, random-effects meta-regressions based on baseline VO2 max were significant. Pilates improves cardiorespiratory fitness regardless of the population's health status. Therefore, it may be an efficacious alternative for both the healthy population and patients suffering from specific disorders to achieve evidenced-based results from cardiorespiratory and neuromotor exercises.

Leisure-Time Running Reduces the Risk of Incident Type 2 Diabetes

OBJECTIVES

We examined the overall association as well as the dose-response relationship between leisure-time running and incident type 2 diabetes.

METHODS

Participants were 19,347 adults aged 18-100 years who were free of cardiovascular disease, cancer, and diabetes at baseline, and who received at least 2 extensive preventive medical examinations between 1974 and 2006. Running and other types of aerobic physical activity were assessed by self-reported leisure-time activities. Type 2 diabetes was defined as fasting glucose ≥126 mg/dL (7.0 mmol/L), physician diagnosis, or insulin use.

RESULTS

During an average follow-up of 6.5 years, 1015 adults developed type 2 diabetes. Approximately 29.5% of adults participated in leisure-time running at baseline. Runners had a 28% (hazard ratio [HR] 0.72; 95% confidence interval [CI], 0.62-0.84) lower risk of developing type 2 diabetes compared with nonrunners during follow-up. The HRs (95% CIs) of type 2 diabetes were 0.98 (0.75-1.28), 0.69 (0.51-0.92), 0.62 (0.45-0.85), 0.78 (0.59-1.04), and 0.57 (0.42-0.79) across quintiles of running time (minutes/week) compared with nonrunners after adjusting for potential confounders, including levels of nonrunning aerobic physical activity. Similar dose-response relationships between running distance (miles/week), frequency (times/week), total amount (MET-minutes/week), and speed (mph) were also observed.

CONCLUSIONS

Participating in leisure-time running is associated with a lower risk of developing type 2 diabetes in adults. Consistent linear dose-response relationships were observed between various running parameters and incident type 2 diabetes, supporting the prescription of running to prevent type 2 diabetes.

Augmented Anabolic Responses after 8-wk Cycling with Blood Flow Restriction

INTRODUCTION

Low-intensity endurance training (ET) performed with blood flow restriction (BFR) can improve muscle strength, cross-sectional area (CSA) and cardiorespiratory capacity. Whether muscle strength and CSA as well as cardiorespiratory capacity (i.e., V˙O2max) and underlying molecular processes regulating such respective muscle adaptations are comparable to resistance and ET is unknown.

PURPOSE

To determine the respective chronic (i.e., 8 wk) functional, morphological, and molecular responses of ET-BFR training compared with conventional, unrestricted resistance training (RT) and ET.

METHODS

Thirty healthy young men were randomly assigned to one of three experimental groups: ET-BFR (n = 10, 4 d·wk, 30-min cycling at 40% of V˙O2max), RT (n = 10, 4 d·wk, 4 sets of 10 repetitions leg press at 70% of one repetition maximum with 60 s rest) or ET (n = 10, 4 d·wk, 30-min cycling at 70% of V˙O2max) for 8 wk. Measures of quadriceps CSA, leg press one repetition maximum, and V˙O2max as well as muscle biopsies were obtained before and after intervention.

RESULTS

Both RT and ET-BFR increased muscle strength and hypertrophy responses. ET-BFR also increased V˙O2max, total cytochrome c oxidase subunit 4 isoform 1 abundance and vascular endothelial growth factor mRNA abundance despite the lower work load compared to ET.

CONCLUSIONS

Eight weeks of ET-BFR can increase muscle strength and induce similar muscle hypertrophy responses to RT while V˙O2max responses also increased postintervention even with a significantly lower work load compared with ET. Our findings provide new insight to some of the molecular mechanisms mediating adaptation responses with ET-BFR and the potential for this training protocol to improve muscle and cardiorespiratory capacity.

Associations of vigorous physical activity with all-cause, cardiovascular and cancer mortality among 64 913 adults

Background

Physical activity recommendations state that for the same energy expenditure, moderate-to-vigorous physical activities (MVPAs) produce similar health benefits. However, few epidemiological studies have tested this hypothesis.

Design

We examined whether, compared with moderate, vigorous activity was associated with larger mortality risk reductions.

Methods

Data from 11 cohorts of the Health Survey for England and the Scottish Health Survey, collected from 1994 to 2011 (mean (SD) follow-up, 9.0 (3.6) years). Adults aged ≥30 years reported MVPA and linkage to mortality records. Exposure was the proportion of self-reported weighted MVPA through vigorous activity. Outcomes were all-cause, cardiovascular disease (CVD) and cancer mortality.

Results

Among 64 913 adult respondents (44% men, 56% women, mean (SD) age, 49.8 (13.6) years), there were 5064 deaths from all-causes, 1393 from CVD and 1602 from cancer during 435 743 person-years of follow-up. Compared with those who reported no vigorous physical activity, and holding constant the volume of weighted MVPA, vigorous activity was associated with additional reductions in mortality risk. For all-cause mortality, the adjusted HR was HR=0.84 (95% CI 0.71, 0.99) and HR=0.84 (95% CI 0.76, 0.94) among those who reported between >0% and<30%, or ≥30% of their activity as vigorous, respectively. For CVD and cancer mortality, point estimates showed similar beneficial associations yet CIs were wider and crossed unity.

Conclusion

Vigorous activities were associated with larger reductions in mortality risk than activities of moderate intensity, but no evidence of dose–response effects was found.

Affective and metabolic responses to self-selected intensity cycle exercise in young men

Self-selected intensity exercise has resulted in greater affective responses (AR) compared to prescribed exercise of similar intensity and many individuals self-select intensity at a moderate level identified by metabolic analysis. As such, self-selected intensity may be an effective alternative for exercise prescription designed to promote adherence and result in health and fitness benefits. Self-selected intensity has not been well described for many subject populations and exercise modes. Therefore, the purpose of this investigation was to measure affective and metabolic responses during self-selected intensity cycle exercise in college-aged men. Thirty-three men (22.4 ± 2.2 yr) performed a peak oxygen consumption test and a 20 min self-selected trial on a cycle ergometer on separate days. Oxygen consumption (VO₂) was measured continuously throughout both exercise sessions. AR were measured using the Feeling Scale and ratings of perceived exertion (RPE) using the OMNI Scale every 5 min during the self-selected trial. χ² analysis was used to determine if a significant proportion of subjects self-selected intensity above 50% VO₂ reserve (VO₂R), defined as a threshold for moderate-intensity exercise and potential cardiorespiratory fitness benefits by American College of Sports Medicine. Mean self-selected intensity was 57.6 ± 11.1%VO₂peak and 89.3 ± 20.2% of ventilatory threshold. Twenty eight of 33 subjects self-selected intensity above 50% VO₂R (p < .05). Self-selected intensity was associated with positive AR (1.8 ± 1.4) and mean RPE of 4.0 ± 1.5. In college-aged men, self-selected intensity cycle exercise was performed at a moderate intensity level and elicited positive AR for most subjects. Therefore, self-selected intensity could be an effective component of an exercise prescription for this population.

Which exercise prescriptions optimize V̇O2 max during cancer treatment?-A systematic review and meta-analysis

The aims of the present systematic review and meta-analysis were to investigate the effect of exercise on maximal oxygen uptake ( V ˙ O 2 m a x ) and to investigate whether exercise frequency, intensity, duration, and volume are associated with changes in V ˙ O 2 m a x among adult patients with cancer undergoing treatment. Medline and Embase through OvidSP were searched to identify randomized controlled trials. Two reviewers extracted data and assessed the risk of bias. The overall effect size and differences in effects for different intensities and frequencies were calculated on change scores and post-intervention V ˙ O 2 m a x data, and the meta-regression of exercise duration and volumes was analyzed using the Comprehensive Meta-Analysis software. Fourteen randomized controlled trials were included in the systematic review, comprising 1332 patients with various cancer types receiving (neo-)adjuvant chemo-, radio-, and/or hormone therapy. Exercise induced beneficial changes in V ˙ O 2 m a x compared to usual care (effect size = 0.46, 95% Confidence Interval = 0.23-0.69). Longer session duration (P = 0.020), and weekly duration (P = 0.010), larger weekly volume (P < 0.001), and shorter intervention duration (P = 0.005) were significantly associated with more beneficial changes in V ˙ O 2 m a x . No differences in effects between subgroups with respect to frequency and intensity were found. In conclusion, exercise has beneficial effects on V ˙ O 2 m a x in patients with cancer undergoing (neo-)adjuvant treatment. As interventions with larger exercise volumes and longer session durations resulted in larger beneficial changes in V ˙ O 2 m a x , exercise frequency, intensity, and duration should be considered carefully for sufficient exercise volume to induce changes in V ˙ O 2 m a x for this patient group.

Fundamental Movement Skill Proficiency and Health Among a Cohort of Irish Primary School Children

PURPOSE

This study aimed to investigate the relationship between fundamental movement skills (FMS) and markers of health among a cohort of Irish primary school children.

METHODS

Participants (N = 296, mean age: 7.99 ± 2.02 years) were senior infant (n = 149, mean age: 6.02 ± 0.39 years) and 4th class (n = 147, mean age: 9.97 ± 0.40 years) students from three primary schools in Cork, Ireland. FMS proficiency (TGMD-2) and markers of health (BMI percentile, waist circumference percentile, blood pressure percentiles, resting heart rate, cardiorespiratory fitness, objectively measured physical activity; PA) measurements were recorded. Correlation and hierarchical stepwise multiple linear regression analyses were conducted to investigate the relationship between FMS and markers of health.

RESULTS

A small, positive relationship was found between FMS (Gross Motor Quotient; GMQ) and cardiorespiratory fitness with small negative correlations between GMQ and 550 m time SDS among 6-year-olds (r(129) = -.286, p < .05) and 10-year-olds (r(132) = -.340, p < .05). A moderate, positive correlation was found between GMQ and light PA (r(71) = .400, p < .05). Small positive correlations were revealed between GMQ and moderate PA (r(71) = .259, p < .05) and between GMQ and total PA (r(71) = .355, p < .05). After adjusting for age, sex, the interaction effect of age and sex, and school attended, FMS explained 15.9% and 24.8% of the variance in 550 m time SDS among 6- and 10-year-olds, respectively, and 6% and 6.5% of the variance in light PA and moderate PA, respectively. After adjusting for age and sex, FMS explained 11.6% of the variance in total PA.

CONCLUSION

A wide range of FMS is important for children's cardiorespiratory fitness and PA.

Comparison between esophageal and intestinal temperature responses to upper-limb exercise in individuals with spinal cord injury

STUDY DESIGN

Experimental study.

OBJECTIVE

Individuals with spinal cord injuries (SCI) may present with impaired sympathetic control over thermoregulatory responses to environmental and exercise stressors, which can impact regional core temperature (T_core) measurement. The purpose of this study was to investigate whether regional differences in T_core responses exist during exercise in individuals with SCI.

SETTING

Rehabilitation centre in Wakayama, Japan.

METHODS

We recruited 12 men with motor-complete SCI (7 tetraplegia, 5 paraplegia) and 5 able-bodied controls to complete a 30-min bout of arm-cycling exercise at 50% V̇O₂ peak reserve. T_core was estimated using telemetric pills (intestinal temperature; T_int) and esophageal probes (T_eso). Heat storage was calculated from baseline to 15 and 30 min of exercise.

RESULTS

At 15 min of exercise, elevations in T_eso (Δ0.39 ± 0.22 °C; P < 0.05), but not T_int (Δ0.04 ± 0.18 °C; P = 0.09), were observed in able-bodied men. At 30 min of exercise, men with paraplegia and able-bodied men both exhibited increases in T_eso (paraplegia: Δ0.56 ± 0.30 °C, P < 0.05; able-bodied men: Δ0.60 ± 0.31 °C, P < 0.05) and T_int (paraplegia: Δ0.38 ± 0.33 °C, P < 0.05; able-bodied men: Δ0.30 ± 0.30 °C, P < 0.05). T_eso began rising 7.2 min earlier than T_int (pooled, P < 0.01). Heat storage estimated by T_eso was greater than heat storage estimated by T_int at 15 min (P = 0.02) and 30 min (P = 0.03) in men with paraplegia. No elevations in T_eso, T_int, or heat storage were observed in men with tetraplegia.

CONCLUSIONS

While not interchangeable, both T_eso and T_int are sensitive to elevations in T_core during arm-cycling exercise in men with paraplegia, although T_eso may have superior sensitivity to capture temperature information earlier during exercise.

Health benefits of electrically-assisted cycling: a systematic review

BACKGROUND

Electrically assisted bicycles (e-bikes) have been highlighted as a method of active travel that could overcome some of the commonly reported barriers to cycle commuting. The objective of this systematic review was to assess the health benefits associated with e-cycling.

METHOD

A systematic literature review of studies examining physical activity, cardiorespiratory, metabolic and psychological outcomes associated with e-cycling. Where possible these outcomes were compared to those from conventional cycling and walking. Seven electronic databases, clinical trial registers, grey literature and reference lists were searched up to November 2017. Hand searching occurred until June 2018. Experimental or observational studies examining the impact of e-cycling on physical activity and/or health outcomes of interest were included. E-bikes used must have pedals and require pedalling for electric assistance to be provided.

RESULTS

Seventeen studies (11 acute experiments, 6 longitudinal interventions) were identified involving a total of 300 participants. There was moderate evidence that e-cycling provided physical activity of at least moderate intensity, which was lower than the intensity elicited during conventional cycling, but higher than that during walking. There was also moderate evidence that e-cycling can improve cardiorespiratory fitness in physically inactive individuals. Evidence of the impact of e-cycling on metabolic and psychological health outcomes was inconclusive. Longitudinal evidence was compromised by weak study design and quality.

CONCLUSION

E-cycling can contribute to meeting physical activity recommendations and increasing physical fitness. As such, e-bikes offer a potential alternative to conventional cycling. Future research should examine the long-term health impacts of e-cycling using rigorous research designs.

Whole-Body Electromyostimulation Improves Performance-Related Parameters in Runners

The aim of this study was to study the effects of a 6-session (one per week) WB-EMS training intervention on maximum oxygen uptake, aerobic and gas exchange thresholds, running economy, and muscular power in male recreational runners. Twelve men were randomized into WB-EMS intervention (n = 6; 27.0 ± 7.5 years; 70.1 ± 11.1 kg; 1.75 ± 0.5 m) or control (n = 6; 27.0 ± 6.1 years; 73.6 ± 3.4 kg; 1.77 ± 0.3 m). The WB-EMS group reduced the running training frequency to one per week and followed one WB-EMS training session per week during 6 weeks. Participants in the control group maintained their usual running endurance training. Each participant completed four assessments: physiological parameters [(i) VO₂max, aerobic and gas exchange threshold values, and (ii) running economy at two intensities], muscular power (vertical jump), and anthropometric parameters both at baseline and after the intervention. Participants in the WB-EMS group improved VO₂max, aerobic and gas exchange threshold values, running economy, and vertical jump (p < 0.05) compared to the control group. There, WB-EMS seems to be an effective training methodology leading to improvements in performance during endurance training volume reduction in male recreational runners.

Interpreting Adaptation to Concurrent Compared with Single-Mode Exercise Training: Some Methodological Considerations

Incorporating both endurance and resistance training into an exercise regime is termed concurrent training. While there is evidence that concurrent training can attenuate resistance training-induced improvements in maximal strength and muscle hypertrophy, research findings are often equivocal, with some suggesting short-term concurrent training may instead further enhance muscle hypertrophy versus resistance training alone. These observations have questioned the validity of the purported 'interference effect' on muscle hypertrophy with concurrent versus single-mode resistance training. This article aims to highlight some methodological considerations when interpreting the concurrent training literature, and, in particular, the degree of changes in strength and muscle hypertrophy observed with concurrent versus single-mode resistance training. Individual training status clearly influences the relative magnitude and specificity of both training adaptation and post-exercise molecular responses in skeletal muscle. The training status of participants is therefore likely a key modulator of the degree of adaptation and interference seen with concurrent training interventions. The divergent magnitudes of strength gain versus muscle hypertrophy induced by resistance training also suggests most concurrent training studies are likely to observe more substantial changes in (and in turn, any potential interference to) strength compared with muscle hypertrophy. Both the specificity and sensitivity of measures used to assess training-induced changes in strength and muscle hypertrophy also likely influence the interpretation of concurrent training outcomes. Finally, the relative importance of any modulation of hypertrophic versus strength adaptation with concurrent training should be considered in context with the relevance of training-induced changes in these variables for enhancing athletic performance and/or functional capacity. Taken together, these observations suggest that aside from various training-related factors, additional non-training-related variables, including participant training status and the measures used to assess changes in strength and muscle hypertrophy, are important considerations when interpreting the outcomes of concurrent training interventions.

Effect of Arthrospira (Spirulina) maxima Supplementation and a Systematic Physical Exercise Program on the Body Composition and Cardiorespiratory Fitness of Overweight or Obese Subjects: A Double-Blind, Randomized, and Crossover Controlled Trial

Excess weight and obesity are major risk factors for many chronic diseases, and weight-loss interventions often include systematic exercise and nutritional supplements. The purpose of this study was to determine the independent/synergistic effects of Arthrospira (Spirulina) maxima supplementation (six weeks, 4.5 g·day-1) and a systematic physical exercise program (six weeks, twice weekly) on the body composition and cardiorespiratory fitness of overweight and obese subjects. To achieve this, 27 overweight and 25 obese sedentary male subjects were assigned to four interventions through a randomized double-blind, crossover controlled trial: A physical exercise program, with (SE) or without (Ex) Spirulina maxima; or no-exercise program, with (Sm) and without (C) Spirulina maxima. The body composition and cardiorespiratory fitness parameters were taken during a maximum intensity test. As compared to the C group, the body fat percentage of the SE, Sm and Ex groups was reduced (p < 0.05), while their maximal oxygen uptake improved (r = -0.40), and obese subjects benefited more significantly. Weight loss, the time to reach fatigue and the onset of blood lactate accumulation were improved in both of the Spirulina maxima supplemented groups, regardless of the subjects' body weight. Spirulina maxima supplementation synergistically improves the effects of systematic exercise on body composition and cardiorespiratory fitness parameters in overweight, but mostly in individuals with obesity.

TRIAL REGISTRATION

Clinical Trials, NCT02837666. Registered 19 July 2016.

What is the effect of aerobic exercise intensity on cardiorespiratory fitness in those undergoing cardiac rehabilitation? A systematic review with meta-analysis

OBJECTIVE

Assess the role of exercise intensity on changes in cardiorespiratory fitness (CRF) in patients with cardiac conditions attending exercise-based cardiac rehabilitation.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

MEDLINE, Embase, CINAHL, SPORTDiscus, PsycINFO and Web of Science.

ELIGIBILITY CRITERIA FOR SELECTION

Studies assessing change in CRF (reported as peak oxygen uptake; V̇O_2peak) in patients post myocardial infarction and revascularisation, following exercise-based cardiac rehabilitation. Studies establishing V̇O_2peak via symptom-limited exercise test with ventilatory gas analysis and reported intensity of exercise during rehabilitation were included. Studies with mean ejection fraction <40% were excluded.

RESULTS

128 studies including 13 220 patients were included. Interventions were classified as moderate, moderate-to-vigorous or vigorous intensity based on published recommendations. Moderate and moderate-to-vigorous-intensity interventions were associated with a moderate increase in relative V̇O_2peak (standardised mean difference±95% CI=0.94±0.30 and 0.93±0.17, respectively), and vigorous-intensity exercise with a large increase (1.10±0.25). Moderate and vigorous-intensity interventions were associated with moderate improvements in absoluteV̇O_2peak (0.63±0.34 and 0.93±0.20, respectively), whereas moderate-to-vigorous-intensity interventions elicited a large effect (1.27±0.75). Large heterogeneity among studies was observed for all analyses. Subgroup analyses yielded statistically significant, but inconsistent, improvements in CRF.

CONCLUSION

Engagement in exercise-based cardiac rehabilitation was associated with significant improvements in both absolute and relative V̇O_2peak. Although exercise of vigorous intensity produced the greatest pooled effect for change in relative V̇O_2peak, differences in pooled effects between intensities could not be considered clinically meaningful.

REGISTRATION

Prospero CRD42016035638.

Home-Based Rehabilitation With Telemonitoring Guidance for Patients With Coronary Artery Disease (Short-Term Results of the TRiCH Study): Randomized Controlled Trial

Background

Cardiac rehabilitation (CR) is an essential part of contemporary coronary heart disease management. However, patients exiting a center-based CR program have difficulty retaining its benefits.

Objective

We aimed to evaluate the added benefit of a home-based CR program with telemonitoring guidance on physical fitness in patients with coronary artery disease (CAD) completing a phase II ambulatory CR program and to compare the effectiveness of this program in a prolonged center-based CR intervention by means of a randomized controlled trial.

Methods

Between February 2014 and August 2016, 90 CAD patients (unblinded, mean age 61.2 years, SD 7.6; 80/90, 89.0% males; mean height 1.73 m, SD 0.7; mean weight 82.9 kg, SD 13; mean body mass index 27.5 kg/m², SD 3.4) who successfully completed a 3-month ambulatory CR program were randomly allocated to one of three groups: home-based (30), center-based (30), or control group (30) on a 1:1:1 basis. Home-based patients received a home-based exercise intervention with telemonitoring guidance consisting of weekly emails or phone calls; center-based patients continued the standard in-hospital CR, and control group patients received the usual care including the advice to remain physically active. All the patients underwent cardiopulmonary exercise testing for assessment of their peak oxygen uptake (VO₂ P) at baseline and after a 12-week intervention period. Secondary outcomes included physical activity behavior, anthropometric characteristics, traditional cardiovascular risk factors, and quality of life.

Results

Following 12 weeks of intervention, the increase in VO₂ P was larger in the center-based (P=.03) and home-based (P=.04) groups than in the control group. In addition, oxygen uptake at the first (P-interaction=.03) and second (P-interaction=.03) ventilatory thresholds increased significantly more in the home-based group than in the center-based group. No significant changes were observed in the secondary outcomes.

Conclusions

Adding a home-based exercise program with telemonitoring guidance following completion of a phase II ambulatory CR program results in further improvement of physical fitness and is equally as effective as prolonging a center-based CR in patients with CAD.

Trial Registration

ClinicalTrials.gov NCT02047942; https://clinicaltrials.gov/ct2/show/NCT02047942 (Archived by WebCite at http://www.webcitation.org/70CBkSURj)

Cardiopulmonary Demand of 16-kg Kettlebell Snatches in Simulated Girevoy Sport

Chan, M, MacInnis, MJ, Koch, S, MacLeod, KE, Lohse, KR, Gallo, ME, Sheel, AW, and Koehle, MS. Cardiopulmonary demand of 16-kg kettlebell snatches in simulated Girevoy Sport. J Strength Cond Res 34(6): 1625-1633, 2020-Kettlebell lifting has become popular both as a strength and conditioning training tool and as a sport in and of itself: Girevoy Sport (GS). Although several kettlebell multimovement protocols have been analyzed, little research has attempted to quantify the aerobic stimulus of the individual events in GS, which could better inform kettlebell-related exercise prescription. The purpose of this study was to quantify the cardiopulmonary demand, assessed primarily by oxygen consumption (V[Combining Dot Above]O2) and heart rate (HR), of continuous high-intensity kettlebell snatches-under conditions relevant to GS-and to compare this demand with a more traditional graded rowing ergometer maximal exercise test. Ten male participants (age = 28.4 ± 4.6 years, height = 185 ± 7 cm, body mass = 95.1 ± 14.9 kg) completed (a) a graded-exercise test on a rowing ergometer to determine maximal oxygen consumption (V[Combining Dot Above]O2max) and maximal heart rate (HRmax) and (b) a graded-exercise test consisting of continuous 16-kg kettlebell snatches to determine peak oxygen consumption (V[Combining Dot Above]O2peak) and peak heart rate (HRpeak) during a simulated GS snatch event. Subjects achieved a V[Combining Dot Above]O2max of 45.7 ± 6.7 ml·kg·min and HRmax of 177 ± 8.3 b·min on the rowing ergometer. The kettlebell snatch test produced a V[Combining Dot Above]O2peak of 37.6 ± 4.4 ml·kg·min (82.7 ± 6.5% V[Combining Dot Above]O2max) and a HRpeak of 174 ± 10 b·min (98.0 ± 3.4% HRmax). These findings suggest that GS kettlebell snatches with 16-kg can provide an adequate aerobic stimulus to improve cardiorespiratory fitness in those with a V[Combining Dot Above]O2max of ≤51 ml·kg·min, according to aerobic training recommendations from the American College of Sports Medicine.

Anaerobic metabolism induces greater total energy expenditure during exercise with blood flow restriction

PURPOSE

We investigated the energy system contributions and total energy expenditure during low intensity endurance exercise associated with blood flow restriction (LIE-BFR) and without blood flow restriction (LIE).

METHODS

Twelve males participated in a contra-balanced, cross-over design in which subjects completed a bout of low-intensity endurance exercise (30min cycling at 40% of [Formula: see text]) with or without BFR, separated by at least 72 hours of recovery. Blood lactate accumulation and oxygen uptake during and after exercise were used to estimate the anaerobic lactic metabolism, aerobic metabolism, and anaerobic alactic metabolism contributions, respectively.

RESULTS

There were significant increases in the anaerobic lactic metabolism (P = 0.008), aerobic metabolism (P = 0.020), and total energy expenditure (P = 0.008) in the LIE-BFR. No significant differences between conditions for the anaerobic alactic metabolism were found (P = 0.582). Plasma lactate concentration was significantly higher in the LIE-BFR at 15min and peak post-exercise (all P≤0.008). Heart rate was significantly higher in the LIE-BFR at 10, 15, 20, 25, and 30min during exercise, and 5, 10, and 15min after exercise (all P≤0.03). Ventilation was significantly higher in the LIE-BFR at 10, 15, and 20min during exercise (all P≤0.003).

CONCLUSION

Low-intensity endurance exercise performed with blood flow restriction increases the anaerobic lactic and aerobic metabolisms, total energy expenditure, and cardiorespiratory responses.

Prescribing 6-weeks of running training using parameters from a self-paced maximal oxygen uptake protocol

Purpose

The self-paced maximal oxygen uptake test (SPV) may offer effective training prescription metrics for athletes. This study aimed to examine whether SPV-derived data could be used for training prescription.

Methods

Twenty-four recreationally active male and female runners were randomly assigned between two training groups: (1) Standardised (STND) and (2) Self-Paced (S-P). Participants completed 4 running sessions a week using a global positioning system-enabled (GPS) watch: 2 × interval sessions; 1 × recovery run; and 1 × tempo run. STND had training prescribed via graded exercise test (GXT) data, whereas S-P had training prescribed via SPV data. In STND, intervals were prescribed as 6 × 60% of the time that velocity at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_{{\text{2max}}}}$$\end{document}V˙O2max (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{{\text{v}}}\dot {V}{{\text{O}}_{{\text{2max}}}}$$\end{document}vV˙O2max) could be maintained (T_max). In S-P, intervals were prescribed as 7 × 120 s at the mean velocity of rating of perceived exertion 20 (_vRPE20). Both groups used 1:2 work:recovery ratio. Maximal oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_{{\text{2max}}}}$$\end{document}V˙O2max), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{{\text{v}}}\dot {V}{{\text{O}}_{{\text{2max}}}}$$\end{document}vV˙O2max, T_{max, v}RPE20, critical speed (CS), and lactate threshold (LT) were determined before and after the 6-week training.

Results

STND and S-P training significantly improved \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_{{\text{2max}}}}$$\end{document}V˙O2max by 4 ± 8 and 6 ± 6%, CS by 7 ± 7 and 3 ± 3%; LT by 5 ± 4% and 7 ± 8%, respectively (all P < .05), with no differences observed between groups.

Conclusions

Novel metrics obtained from the SPV can offer similar training prescription and improvement in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_{{\text{2max}}}}$$\end{document}V˙O2max, CS and LT compared to training derived from a traditional GXT.

Evidence-Based Exercise Recommendations to Reduce Hepatic Fat Content in Youth- a Systematic Review and Meta-Analysis

The main purposes of this study were to elucidate the effects of supervised-exercise training (ET) interventions on hepatic fat content and on non-alcoholic fatty liver disease (NAFLD) prevalence in children and adolescents and to provide information about the optimal ET prescription (type, intensity, volume, and frequency) needed to reduce hepatic fat content in youths. Supervised-ET interventions performed in children and adolescents (6-19 years) that provided results of exercise effects on hepatic fat content or NAFLD prevalence were included. Supervised-exercise significantly reduced hepatic fat content compared to the control groups. Lifestyle interventions that included supervised-ET significantly reduced the prevalence of NAFLD. This systematic review and meta-analysis shows that supervised-ET could be an effective strategy in the management and prevention of NAFLD in children and adolescents. Both aerobic and resistance ET, at vigorous or moderate-to-vigorous intensities, with a volume ≥60 min/session and a frequency ≥3 sessions/week, aiming to improve cardiorespiratory fitness and muscular strength, had benefits on hepatic fat content reduction in youth. These data concur with the international recommendations of physical activity for health promotion in youth and may be useful when designing ET programs to improve and prevent hepatic steatosis in the pediatric population.

Using Metabolic Equivalents in Clinical Practice

Metabolic equivalents, or METs, are routinely employed as a guide to exercise training and activity prescription and to categorize cardiorespiratory fitness (CRF). There are, however, inherent limitations to the concept, as well as common misapplications. CRF and the patient's capacity for physical activity are often overestimated and underestimated, respectively. Moreover, frequently cited fitness thresholds associated with the highest and lowest mortality rates may be misleading, as these are influenced by several factors, including age and gender. The conventional assumption that 1 MET = 3.5 mL O₂/kg/min has been challenged in numerous studies that indicate a significant overestimation of actual resting energy expenditure in some populations, including coronary patients, the morbidly obese, and individuals taking β-blockers. These data have implications for classifying relative energy expenditure at submaximal and peak exercise. Heart rate may be used to approximate activity METs, resulting in a promising new fitness metric termed the "personal activity intelligence" or PAI score. Despite some limitations, the MET concept provides a useful method to quantitate CRF and define a repertoire of physical activities that are likely to be safe and therapeutic. In conclusion, for previously inactive adults, moderate-to-vigorous physical activity, which corresponds to ≥3 METs, may increase MET capacity and decrease the risk of future cardiac events.

Cardiovascular Stress During Inpatient Spinal Cord Injury Rehabilitation

OBJECTIVES

(1) To measure the amount of cardiovascular stress, self-reported physical activity, and accelerometry-measured physical activity by individuals with spinal cord injury (SCI) during physical therapy (PT) and occupational therapy (OT); and (2) to investigate the relations between these measures.

DESIGN

Observational study.

SETTING

Two inpatient SCI rehabilitation centers.

PARTICIPANTS

Patients with SCI (N=87) were recruited from consecutive admissions to rehabilitation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Heart rate was recorded by a Holter monitor, whereas physical activity was captured by self-report (Physical Activity Recall Assessment for People with SCI questionnaire) and real-time wrist accelerometry during a total of 334 PT and OT inpatient sessions. Differences between individuals with paraplegia and tetraplegia were assessed via Mann-Whitney U tests. Spearman correlations were used to explore the relation between measurements of physical activity and heart rate.

RESULTS

Time spent at a heart rate within a cardiovascular training zone (≥40% heart rate reserve) was low and did not exceed a median of 5 minutes. In contrast, individuals reported at least 60 minutes of higher-intensity time during therapy. There was a low but statistically significant correlation between all measures.

CONCLUSIONS

The cardiovascular stress incurred by individuals with SCI during inpatient PT and OT sessions is low and not sufficient to obtain a cardiovascular training effect to optimize their neurologic, cardiovascular, or musculoskeletal health; this represents a lost opportunity to maximize rehabilitation. Self-reported minutes of higher-intensity physical activity do not reflect actual time spent at a higher intensity measured objectively via a heart rate monitor.

Noninvasive positive pressure ventilation enhances the effects of aerobic training on cardiopulmonary function

Purpose

The purpose of this study was to determine the effect of aerobic training under noninvasive positive pressure ventilation (NPPV) on maximal oxygen uptake (V˙O2max).

Methods

Ten healthy young male volunteers participated in the study. Before the training, stroke volume (SV) and cardiac output (CO) were measured in all subjects under 0, 4, 8, and 12 cmH₂O NPPV at rest. Then, the subjects exercised on a cycle ergometer at 60% of pre-training V˙O2max for 30 min daily for 5 consecutive days with/without NPPV. The 5-day exercise protocol was repeated after a three-week washout period without/with NPPV. The primary endpoint was changes in V˙O2max. The secondary endpoints were changes in SV, CO, maximum heart rate (HR_max), maximum respiratory rate (RR_max), maximum expiratory minute volume (VE_max) and the percent change in plasma volume (PV).

Results

NPPV at 12 cmH₂O significantly reduced SV and CO at rest. V˙O2max significantly increased after 5 days training with and without NPPV, but the magnitude of increase in V˙O2max after training under 12 cmH₂O NPPV was significantly higher than after training without NPPV. VE_max significantly increased after training under NPPV, but not after training without NPPV. HR_max and RR_max did not change during training irrespective of NPPV. The percent change in PV was similar between training with and without NPPV. The 5-day training program with NPPV resulted in greater improvement in V˙O2max than without NPPV.

Conclusions

Aerobic training under NPPV has add-on effects on V˙O2max and exercise-related health benefits in healthy young men.

Personalized Activity Intelligence (PAI) for Prevention of Cardiovascular Disease and Promotion of Physical Activity

PURPOSE

To derive and validate a single metric of activity tracking that associates with lower risk of cardiovascular disease mortality.

METHODS

We derived an algorithm, Personalized Activity Intelligence (PAI), using the HUNT Fitness Study (n = 4631), and validated it in the general HUNT population (n = 39,298) aged 20-74 years. The PAI was divided into three sex-specific groups (≤50, 51-99, and ≥100), and the inactive group (0 PAI) was used as the referent. Hazard ratios for all-cause and cardiovascular disease mortality were estimated using Cox proportional hazard regressions.

RESULTS

After >1 million person-years of observations during a mean follow-up time of 26.2 (SD 5.9) years, there were 10,062 deaths, including 3867 deaths (2207 men and 1660 women) from cardiovascular disease. Men and women with a PAI level ≥100 had 17% (95% confidence interval [CI], 7%-27%) and 23% (95% CI, 4%-38%) reduced risk of cardiovascular disease mortality, respectively, compared with the inactive groups. Obtaining ≥100 PAI was associated with significantly lower risk for cardiovascular disease mortality in all prespecified age groups, and in participants with known cardiovascular disease risk factors (all P-trends <.01). Participants who did not obtain ≥100 PAI had increased risk of dying regardless of meeting the physical activity recommendations.

CONCLUSION

PAI may have a huge potential to motivate people to become and stay physically active, as it is an easily understandable and scientifically proven metric that could inform potential users of how much physical activity is needed to reduce the risk of premature cardiovascular disease death.

Comparison of energy expenditure and heart rate responses between three commercial group fitness classes

OBJECTIVES

The objectives of this study were to compare the energy expenditure and heart rate responses between three commercial group fitness classes (group resistance exercise [PUMP]; indoor stationary cycling [RIDE]; and step aerobics [STEP]).

DESIGN

One-Way Repeated Measures incorporating a Latin Square Design for class randomisation.

METHODS

Ten participants (5 males and 5 females) completed each group fitness class in random order with energy expenditure and heart rate determined using an Actiheart monitor.

RESULTS

STEP and RIDE produced significantly (p<0.05) higher average heart rates (HR_avg) (85.8±5.1% and 86.4±4.3% of HR_max, respectively) compared to PUMP (73.7±7% of HR_max). HR_peak was also significantly (p<0.05) higher in STEP and RIDE (97.1±4.7% and 95.6±4.5% of HR_max, respectively) when compared with the PUMP class (90±5.9% of HR_max). Total energy expenditure (TEE), both absolute and relative, were significantly (p<0.05) higher for STEP (2101.7±560.2kJ and 0.59±0.07kJkg^-1min^-1) and RIDE (1880.4±420kJ and 0.58±0.03kJkg^-1min^-1) when compared with the PUMP class (1385.1±504kJ and 0.36±0.07kJkg^-1min^-1).

CONCLUSIONS

These data suggest that overall exercise intensity and energy expenditure was highly comparable between RIDE and STEP, which suggests these group fitness classes are more effective for developing cardiovascular fitness and assisting with weight management compared with group resistance exercise classes when performed on a regular basis.

Association of Occupational and Leisure-Time Physical Activity with Aerobic Capacity in a Working Population

Introduction

Objective data on the association of maximal aerobic capacity (VO_2max) with work related physical activity are sparse. Thus, it is not clear whether occupational physical activity (OPA) contributes to an increase of VO_2max. This study examined the association of VO_2max with work and non-work related physical activity in a Swiss working population.

Methods

In this cross-sectional study, a total of 337 healthy and full-time employed adults were recruited. Demographic data, height, weight and BMI were recorded in all subjects. Participants were classified into nine occupational categories (ISCO-88) and merged into three groups with low, moderate, and high OPA. Physical activity was objectively measured by the SenseWear Mini Armband on seven consecutive days (23 hours per day). Participants were regarded as sufficiently active when accumulating ≥30 min of moderate-to-vigorous physical activity per day. VO_2max was evaluated using the multistage 20-meter shuttle run test.

Results

Data of 303 participants were considered for analysis (63% male, age 33 yrs, SD 12). Multiple linear regression analysis (adjusted R² = 0.69) revealed significant positive associations of VO_2max with leisure-time physical activity (LTPA) at vigorous intensity (β = 0.212) and sufficient moderate-to-vigorous physical activity (β = 0.100) on workdays. Female gender (β = -0.622), age (β = -0.264), BMI (β = -0.220), the ratio of maximum to resting heart rate (β = 0.192), occupational group (low vs. high OPA, β = -0.141), and smoking (β = -0.133) were also identified as independent predictors of VO_2max.

Conclusions

The present results suggest that VO_2max is positively associated with LTPA, but not with OPA on workdays. This finding emphasizes the need for employees to engage in sufficient high-intensity physical activity in recreation for maintaining or improving VO_2max with regard to health benefits.

Aerobic Cycle Exercising in a Rehabilitation Program with a Wider Choice of Intensity

When patients in rehabilitation programs use cycle ergometers for aerobic fitness training, the exercise intensity is often restricted to a small range of heart rate. In this study, a wider choice of intensities was left to the patients without giving up the potential to reduce cardiac risks factors. 24 patients in 3-wk. rehabilitation programs could choose the exercise intensity up to a workload limit preset by the physical therapist. 20 of them exercised at an intensity covering the full range between the aerobic and anaerobic lactate threshold and 4 a little above. The opportunity to vary the workload was frequently used by 67%. In 75% of the exercise sessions, the patients' average heart rates exceeded moderate heart-rate targets recommended in rehabilitation and health promotion for people with moderate cardiac risks without a graded exercise test. In 72% of these sessions, the anaerobic lactate threshold at 4 mmol/L was not exceeded. But a tendency of 33% of the patients to exercise at higher blood lactate or blood pressure levels underlined the necessity of limiting the exercise intensity.

Unreliability of the %VO2 reserve versus %heart rate reserve relationship for aerobic effort relative intensity assessment in chronic heart failure patients on or off beta-blocking therapy

BACKGROUND

Percentage of heart rate reserve (%HRR) has been shown to be equivalent to percentage of VO2 reserve (%VO2R) in normal individuals, but it is not clear whether this is also true for chronic heart failure (CHF) patients.

DESIGN

This study aimed to evaluate the reliability of the %VO2R versus %HRR relationship for aerobic effort relative intensity assessment in CHF patients.

METHODS

We studied 388 patients with CHF, of whom 213 were on carvedilol (CHF on betab) and 175 were off the drug (CHF off betab), and 40 normal individuals (N). %VO2R and %HRR values were evaluated at matched steps during cardiopulmonary exercise testing. The %VO2R versus %HRR regression was determined for each group (CHF, CHF on betab, CHF off betab, N) as a whole and as the mean of individual regressions.

RESULTS

%VO2R strongly correlated with %HRR in both N and CHF, at both group and mean individual regressions, with slope and y-intercept values significantly lower and higher, respectively, in CHF than N. The 95% prediction interval of %VO2R for a given %HRR value was 24% points in N but rose to 41 in CHF, and the mean regression line coincided with identity line in N but not in CHF. These results were independent of beta-blockade.

CONCLUSIONS

In CHF patients the %VO2R versus %HRR relationship is unreliable for assessment of aerobic effort relative intensity, because of a large prediction interval of %VO2R and lack of coincidence with the identity line, independently of beta-blocking therapy. This implies that the %VO2R versus %HRR relationship should be determined directly in each patient.

Improved Cardiorespiratory Fitness With Aerobic Exercise Training in Individuals With Traumatic Brain Injury

OBJECTIVE

To examine cardiorespiratory fitness in individuals with traumatic brain injury (TBI), before and following participation in a supervised 12-week aerobic exercise training program.

METHODS

Ten subjects with nonpenetrating TBI (TBI severity: mild, 50%; moderate, 40%; severe, 10%; time since injury [mean ± SD]: 6.6 ± 6.8 years) performed exercise training on a treadmill 3 times a week for 30 minutes at vigorous intensity (70%-80% of heart rate reserve). All subjects completed a cardiopulmonary exercise test, with pulmonary gas exchange measured and a questionnaire related to fatigue (Fatigue Severity Scale) at baseline and following exercise training.

RESULTS

After training, increases (P < .01) in peak oxygen consumption ((Equation is included in full-text article.); +3.1 ± 2.4 mL/min/kg), time to volitional fatigue (+1.4 ± 0.8 minutes), and peak work rate (+59 ± 43 W) were observed. At the anaerobic threshold, (Equation is included in full-text article.)(+3.6 ± 2.1 mL/kg/min), treadmill time (+1.8 ± 1.1 minutes), and work rate (+37 ± 39 W) were higher (P < .01) following exercise training. Subjects also reported significantly lower (P < .05) Fatigue Severity Scale composite scores (-0.9 ± 1.3) following exercise training.

CONCLUSION

These findings suggest that individuals with TBI may benefit from participation in vigorous aerobic exercise training with improved cardiorespiratory fitness and diminished fatigue.

Body Composition, Fitness Status, and Health Behaviors Upon Entering College: An Examination of Female College Students From Diverse Populations

Although poor health-related behaviors that impact development of chronic diseases begin much earlier than when actual disease is evident, few studies have examined health behaviors in college students, who may be at an important transitional period where early intervention could prevent development of chronic diseases. The purpose of this study was to examine health-related factors in female college students (N = 61) by race/ethnicity and weight status. We found significant differences in health profiles between non-Hispanic White (White) and African American students, including greater physical fitness and healthier diets among White students. Overweight/obese students had worse health profiles than healthy BMI students. Furthermore, weight status was significantly associated with cardiovascular fitness. This supports a focus on PA promotion for interventions in the period of emerging adulthood, alongside the other healthy behaviors, to elicit improvements in weight status and potential reduction of chronic disease risks.

Guidelines for Adult Stroke Rehabilitation and Recovery: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this guideline is to provide a synopsis of best clinical practices in the rehabilitative care of adults recovering from stroke.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council's Scientific Statement Oversight Committee and the AHA's Manuscript Oversight Committee. The panel reviewed relevant articles on adults using computerized searches of the medical literature through 2014. The evidence is organized within the context of the AHA framework and is classified according to the joint AHA/American College of Cardiology and supplementary AHA methods of classifying the level of certainty and the class and level of evidence. The document underwent extensive AHA internal and external peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

Stroke rehabilitation requires a sustained and coordinated effort from a large team, including the patient and his or her goals, family and friends, other caregivers (eg, personal care attendants), physicians, nurses, physical and occupational therapists, speech-language pathologists, recreation therapists, psychologists, nutritionists, social workers, and others. Communication and coordination among these team members are paramount in maximizing the effectiveness and efficiency of rehabilitation and underlie this entire guideline. Without communication and coordination, isolated efforts to rehabilitate the stroke survivor are unlikely to achieve their full potential.

CONCLUSIONS

As systems of care evolve in response to healthcare reform efforts, postacute care and rehabilitation are often considered a costly area of care to be trimmed but without recognition of their clinical impact and ability to reduce the risk of downstream medical morbidity resulting from immobility, depression, loss of autonomy, and reduced functional independence. The provision of comprehensive rehabilitation programs with adequate resources, dose, and duration is an essential aspect of stroke care and should be a priority in these redesign efforts. (Stroke.2016;47:e98-e169. DOI: 10.1161/STR.0000000000000098.).

Comparative effects of three 48-week community-based physical activity and exercise interventions on aerobic capacity, total cholesterol and mean arterial blood pressure

AIM

Insufficient research examines the treatment effectiveness of real-world physical activity (PA) interventions.

PURPOSE

We investigated the effects of 3 interventions on directly measured cardiovascular variables. All treatments and measures were administered in community settings by fitness centre staff.

METHODS

Participants were sedentary individuals receiving no medication to reduce cardiovascular disease (CVD) risk (n=369, age 43 ±5 years). In a semirandomised design, participants were allocated to a structured gym exercise programme (STRUC), unstructured gym exercise (FREE), physical activity counselling (PAC) or a measurement-only control condition (CONT). Measures were: predicted aerobic capacity (VO2: mL kg min), mean arterial blood pressure (MAP: mm Hg) and total cholesterol (TC: mmol/L), and were taken at baseline and 48 weeks.

RESULTS

Data analysis indicated a statistically significant deterioration in TC in CONT (0.8%, SD=0.5, p=0.005), and a statistically significant improvement in MAP in STRUC (2.5%, SD=8.3, p=0.004). Following a median split by baseline VO2, paired-sample t tests indicated significant improvements in VO2 among low-fit participants in STRUC (3.5%, SD=4.8, p=0.003), PAC (3.3%, SD=7.7, p=0.050) and FREE (2.6%, SD=4.8, p=0.006), and significant deterioration of VO2 among high-fit participants in FREE (-2.0%, SD=5.6, p=0.037), and PAC (-3.2%, SD=6.4, p=0.031).

CONCLUSIONS

Several forms of PA may offset increased cholesterol resulting from inactivity. Structured PA (exercise) might be more effective than either unstructured PA or counselling in improving blood pressure, and community-based PA interventions might be more effective in improving VO2 among low-fit than among high-fit participants.

Specific Intensity for Peaking: Is Race Pace the Best Option?

Background:

The peaking period for endurance competition is characterized for a relative increase of the intensity of training, after a longer period of training relatively dominated by lower intensity and higher volume

Objectives:

The present study was designed to compare physiological and 10 km performance effects of high intensity training (HIT) versus race pace interval training (RP) during peaking for competition in well-trained runners.

Patients and Methods:

13 athletes took part in the study, they were divided into two groups: HIT and RP. HIT performed short intervals at ~105% of the maximal aerobic velocity (MAV), while RP trained longer intervals at a speed of ~90% of the MAV (a speed approximating 10 km race pace). After 12 weeks of baseline training, the athletes trained for 6 weeks under one of the two peaking regimes. Subjects performed 10 km prior to and after the intervention period. The total load of training was matched between groups during the treatment phase. Subjects completed a graded treadmill running test until volitional exhaustion prior to each 10 km race. MAV was determined as the minimal velocity eliciting maximal oxygen consumption (VO₂max).

Results:

Both groups significantly improved their 10 km time (35 minutes 29 seconds ± 1 minutes 41 seconds vs 34 minutes 53 seconds ± 1 minutes 55 seconds, P < 0.01 for HIT; 35 minutes 27 seconds ± 1 minutes 40 seconds vs 34 minutes 53 seconds ± 1 minutes 18 seconds P < 0.01 for RP). VO₂max increased after HIT (69 ± 3.6 vs 71.5 ± 4.2 ml.Kg^-1.min^-1, P < 0.05); while it didn’t for RP (68.4 ± 6 vs 69.8 ± 3 ml.Kg^-1.min^-1, p>0.05). In contrast, running economy decreased significantly after HIT (210 ± 6 ml.Kg^-1.km^-1 vs 218 ± 9, P < 0.05).

Conclusions:

A 6 week period of training at either 105% of MAV or 90% of MAV yielded similar performance gains in a 10km race performed at ~90% MAV. Therefore, the physiological impact of HIT training seems to be positive for VO2max but negative for running economy.

Prescription of walking exercise intensity from the 6-minute walk test in people with chronic obstructive pulmonary disease

PURPOSE

The 6-minute walk test (6MWT) is widely used in clinical practice, particularly to assess functional exercise capacity and to prescribe walking training intensity in people with chronic obstructive pulmonary disease (COPD). However, the actual walking intensity prescribed from the 6MWT, in terms of percent peak oxygen uptake (%(Equation is included in full-text article.)O2peak) and percent (Equation is included in full-text article.)O2 reserve (%(Equation is included in full-text article.)O2R), has not been previously reported. This study aims to examine the exercise intensity when walking training is prescribed at 80% average 6MWT speed.

METHODS

Patients with COPD (N = 45) were recruited. Peak (Equation is included in full-text article.)O2 from an incremental cycle test and 6MWT and (Equation is included in full-text article.)O2 from a 10-minute walking exercise (Walk-10) were measured by a portable metabolic system (Cosmed K4b; Cosmed, Rome, Italy). Walk-10 was done on the same oval course as the 6MWT. Participants were asked to walk at 80% average 6MWT speed for 10 minutes continuously.

RESULTS

Four participants could not complete Walk-10 and 2 did not perform Walk-10 due to low 6MWT distance. The remaining 39 participants with mean (SD) forced expiratory volume in 1 minute of 58 (19)% predicted completed Walk-10. The mean intensity of Walk-10 was 69 (17)% (Equation is included in full-text article.)O2R or 77 (13)% (Equation is included in full-text article.)O2peak. Steady-state (Equation is included in full-text article.)O2 was achieved within the first 4 minutes of Walk-10.

CONCLUSION

Walking exercise prescribed at 80% average 6MWT speed resulted in a high but tolerable exercise intensity that is likely to result in training benefits in most people with COPD.

Comparison of aerobic exercise intensity prescription methods in breast cancer

INTRODUCTION

Exercise plays an important role in cancer rehabilitation, but a precise prescription of exercise intensity is required to maximize the benefits of this intervention. It is unknown whether different methods of prescribing aerobic exercise intensity achieve the same intensity. Breast cancer treatments may alter exercise response and thereby may affect the accuracy of these methods.

PURPOSE

The purpose of this study was to compare the accuracy and achieved intensity of four common methods of prescribing exercise intensity within and between breast cancer patients recently finished chemotherapy (n = 10), survivors finished treatment (n = 10), and healthy controls (n = 10).

METHODS

The methods compared were as follows: the American College of Sports Medicine's metabolic equation for treadmill walking (METW), heart rate reserve (HRR), direct heart rate (DIRECT HR), and RPE. The methods were used to prescribe 60% oxygen consumption reserve (VO2R) in four randomly assigned 10-min periods of treadmill walking with expired gas collection to evaluate 1) achieved intensity (measured % VO2R) and 2) accuracy (defined as: [60% VO2R-achieved intensity]).

RESULTS

The accuracy of the methods was not equivalent across groups (P = 0.04). HRR and METW did not differ across groups and were most accurate in patients. HRR, METW, and DIRECT HR were all more accurate than RPE in survivors (P ≤ 0.01). RPE was the least accurate in all groups. The accuracy of DIRECT HR was much lower in patients than that in survivors and controls (P ≤ 0.01).

CONCLUSIONS

The four methods of exercise intensity prescription varied in accuracy in prescribing 60% VO2R and did not achieve equivalent exercise intensities within breast cancer patients, survivors, and healthy controls. HRR and METW were the most accurate methods for exercise intensity prescription in breast cancer patients and survivors.

Promoting neuroplasticity for motor rehabilitation after stroke: considering the effects of aerobic exercise and genetic variation on brain-derived neurotrophic factor

Recovery of motor function after stroke involves relearning motor skills and is mediated by neuroplasticity. Recent research has focused on developing rehabilitation strategies that facilitate such neuroplasticity to maximize functional outcome poststroke. Although many molecular signaling pathways are involved, brain-derived neurotrophic factor (BDNF) has emerged as a key facilitator of neuroplasticity involved in motor learning and rehabilitation after stroke. Thus, rehabilitation strategies that optimize BDNF effects on neuroplasticity may be especially effective for improving motor function poststroke. Two potential poststroke rehabilitation strategies that consider the importance of BDNF are the use of aerobic exercise to enhance brain function and the incorporation of genetic information to individualize therapy. Converging evidence demonstrates that aerobic exercise increases BDNF production and consequently enhances learning and memory processes. Nevertheless, a common genetic variant reduces activity-dependent secretion of the BDNF protein. Thus, BDNF gene variation may affect response to motor rehabilitation training and potentially modulate the effects of aerobic exercise on neuroplasticity. This perspective article discusses evidence that aerobic exercise promotes neuroplasticity by increasing BDNF production and considers how aerobic exercise may facilitate the acquisition and retention of motor skills for poststroke rehabilitation. Next, the impact of the BDNF gene val66met polymorphism on motor learning and response to rehabilitation is explored. It is concluded that the effects of aerobic exercise on BDNF and motor learning may be better exploited if aerobic exercise is paired more closely in time with motor training. Additionally, information about BDNF genotype could provide insight into the type and magnitude of effects that aerobic exercise may have across individuals and potentially help guide an individualized prescription of aerobic exercise to enhance motor rehabilitation poststroke.

Continuous and high-intensity interval training: which promotes higher pleasure?

OBJECTIVES

To compare the psychological responses to continuous (CT) and high-intensity interval training (HIT) sessions.

METHODS

Fifteen men attended one CT session and one HIT session. During the first visit, the maximum heart rate, VO2Peak and respiratory compensation point (RCP) were determined through a maximal cardiopulmonary exercise test. The HIT stimulus intensity corresponded to 100% of VO2Peak, and the average intensity of both sessions was maintained at 15% below the RCP. The order of the sessions was randomized. Psychological and physiological variables were recorded before, during and after each session.

RESULTS

There were no significant differences between the average percentages of VO2 during the two exercise sessions (HIT: 73.3% vs. CT: 71.8%; p = 0.779). Lower responses on the feeling scale (p≤0.01) and higher responses on the felt arousal scale (p≤0.001) and the rating of perceived exertion were obtained during the HIT session. Despite the more negative feeling scale responses observed during HIT and a greater feeling of fatigue (measured by Profile of Mood States) afterwards (p<0.01), the physical activity enjoyment scale was not significantly different between the two conditions (p = 0.779).

CONCLUSION

Despite the same average intensity for both conditions, similar psychological responses under HIT and CT conditions were not observed, suggesting that the higher dependence on anaerobic metabolism during HIT negatively influenced the feeling scale responses.

The intensity of chair-assisted exercises in cognitively healthy older adults

INTRODUCTION

The American College of Sports Medicine prescribes regular performance of at least moderate-intensity physical activity for healthy aging. This study examined whether 1 session of 30 min of chair-assisted exercises for the elderly meets this intensity criterion.

METHOD

This cross-sectional study included 47 cognitively healthy volunteers (mean age 84 years). During the performance of 30 min of chair-assisted exercises the authors determined oxygen uptake (VO2), carbon dioxide production, heart rate (HR), and rating of perceived exertion (RPE). These measures were expressed as a percentage of the estimated maximal VO2 (VO2max) and the estimated maximal HR (HRmax) and estimated as metabolic equivalent units (METs).

RESULTS

Participants performed chair-assisted exercises at 61.0% ± 14.7% of VO2max, 67.6% ± 11.3% HRmax, 3.9 ± 0.9 METs, and 13.1 ± 2.1 RPE.

CONCLUSIONS

The intensity of these chair-assisted exercises is at least moderate for older adults, which is necessary for healthy aging.