Measure Of Aerobic Capacity Research Articles

Assessment of Maximal Oxygen Uptake (VO2 Max) in Athletes and Nonathletes Assessed in Sports Physiology Laboratory.

Athletes' physical prowess plays a crucial role in their ability to succeed in any sporting endeavor. Each athlete on the field must have an exceptional aerobic capacity to withstand fierce competition and stringent regulatory guidelines.Maximal oxygen uptake (VO2max) is a quantitative measure of aerobic capacity and is regardedas one of themost reliable indicators ofcardiorespiratory and overall physical fitness of an individual by sports physiologists. The study aims to evaluate the VO2 max of athletes in comparison with nonathletes during treadmill and lower limb cycle ergometry exercises as assessed in the Sports Physiology Laboratory of a rural medical college.Treadmill exercise and bicycle ergometer exercise are the most common to perform as indoor aerobic exercises to assess one's physical fitness. Both these tests are equally useful in eliciting cardiac and vascular responses, so both these modalities were used to assess aerobic fitness. This cross-sectional study, which examined participants aged 17-25, included 30 athletes (cases) and 120 age- and sex-matched controls. The VO2 max was evaluated using the Metabolic Module of Lab Chart Software, which was investigated through the PowerLab data acquisition system, AD Instruments (Bella Vista,NSW, Australia). The mean age of male athletes was 20.51 ± 2.69 years and of female athletes was 20.53 ± 1.62 years. The mean and standard deviation of VO2 max on the treadmill for male cases was 52.37 ± 8.78 mL/kg/min and for female cases was 40.96 ± 4.06 mL/kg/min, and on a cycle ergometer for male cases was 45.21 ± 9.43 mL/kg/min and for female cases was 34.32 ± 5.12 mL/kg/min. For the control group, the mean age of control males was 21.2 ± 2.62 years and of control females was 20.36 ± 1.5 years. The mean and standard deviationof VO2 max on the treadmill for control males was 33.35 ± 3.77 mL/kg/min and for control females was 25.09 ± 7.07 mL/kg/min, and on the cycle ergometer for control males was 34.17 ± 2.75 mL/kg/min and for control females was 24.15 ± 5.35 mL/kg/min. This study showed significantly (p < 0.001) higher VO2 max levels in athletes of both genders compared to their age- and sex-matched controls upon exercise on the treadmill and cycle ergometer. This study underscores the significance of better cardiorespiratory fitness in athletes than nonathletes, giving pertinent insights about their aerobic capacity, which is precisely measured and expressed in terms of VO2.

Hypertension is associated with reduced medial temporal lobe neural flexibility in older African Americans

AbstractBackgroundHypertension disproportionately affects African Americans (AA) and is an established mid‐life risk factor for Alzheimer’s disease (AD). However, previous research suggests there is inconclusive data examining late‐life hypertension and Alzheimer’s risk. Recently, a dynamic rearrangement (neural flexibility) imaging method was validated for evaluating cognitive decline in the medial temporal lobe (MTL), which is a key region affected by AD. But whether hypertension mediates MTL neural flexibility in older AA individuals is unknown. Therefore, we investigated MTL flexibility in older hypertensive and normotensive AA.MethodOne hundred and thirteen AA (60‐74y) completed demographic surveys, weight and height measurements, resting blood pressure (BP) screening procedure, and a 6‐minute walking distance test as an indirect measure of aerobic capacity. All individuals also completed a 10‐minute resting‐state functional magnetic resonance screening to assess MTL neural flexibility. Participants were separated into normotensive (systolic BP &lt; 130mmHg, n = 36, 83% female, 64.8 ± 0.4y; 13.8 ± 0.2y of education) vs. hypertensive (systolic BP ³ 130mmHg, n = 77, 82% female, 66.4 ± 0.3y; 14.1 ± 0.1y of education). An ANCOVA was used to examine group differences in MTL neural flexibility with age, sex, and education used as covariates.ResultAlthough individuals with hypertension had a higher BMI (36.9 ± 1.8 vs. 31.3 ± 2.6 kg/m2, p = .070), this was not statistically different. However, normotensive participants had significantly higher MTL neural flexibility compared to hypertensive individuals (.42 ± .23 vs. .32 ± .25, p = .04), and this was independent of estimated aerobic capacity (14.9 ± 2.3 vs. 14.9 ± 2.5 ml/kg/min; ml/kg/min; p = .864).ConclusionHypertensive AA between the ages 60‐74 years old demonstrated lower MTL neural flexibility compared to their normotensive counterparts. These results were independent of obesity and aerobic fitness, suggesting additional work is needed to understand how blood pressure mediates neuronal connectivity to prevent and/or treat AD cognitive decline in AA.

Exploring the Relationship Between the Indices of Body Composition With Grip Strength Performance and Peak VO2.

Background The importance of measurements of body composition in terms of various indices including Body Mass Index (BMI), Body Surface Area (BSA), Body Size Index (BSI), and Waist to Height ratio (WtHR) in the diagnosis of health risks and mortality outcome analysis has largely been limited to their use relating to determining abdominal obesity. The understanding of the extent of implications of the newer, underutilized indices of body composition is deficient. Peak VO2(maximal oxygen uptake) majorly serves for the evaluation of the measure of aerobic capacity. Grip strength performance is a simple, primary, objective predictor of overall physical status and muscular and cardiovascular fitness. This study aimed to derive the relationship between a gamut of parameters such as BMI, BSA, WtHR, BSI, grip strength performance and peak VO2 investigated using the latest scientific methodology in a cross-section of the population in a rural tertiary care center. Methodology This study was a descriptive, cross-sectional study carried out in a rural medical college in central India. Sixty participants from the healthcare setting were considered eligible for the study within the age group of 18 to 45 years. Anthropometric assessments like height (in cm), weight (in kg), waist circumference (in cm), and BMI were carried out. BSA, WtHR, and BSI were calculated using the respective formulae.VO2max (maximal oxygen uptake) recordings were done using thetreadmill/ergometer andmetabolic module of LabChart software (Bella Vista,New South Wales, Australia).Grip Strength Performance was quantified by measuring the amount of static force with which the hand is able to squeeze a transducer. It was measured using Grip Force Transducer (MLT004 / ST) from AD Instruments (Bella Vista,New South Wales, Australia). Results Upon analysis, a significant negative correlation was obtained between BSI and BMI (r= -0.51, p<0.0001) whereas a significant positive correlation was found between BSA and BMI (r= 0.71, p< 0.0001). A significant correlation was also seen between WtHR and BMI (r= 0.71, p< 0.0001) while a negative significant correlation between peak VO2 and BMI (r= -024,p=0.0425) was deduced. Similarly, a negative correlation was evident between BSA and BMI (r= -0.46, p=0.0002) with a positive correlation between WtHR and BSA (r= 0.30,p=0.0188). Grip strength performance positively correlated with BSA (r= 0.58, p< 0.0001) whereas peak VO2 showed a significant negative correlation with WtHR (r= -026,p=0.043). There was also a positive significant correlation between grip strength performance and peak VO2 (r= 0.37, p=0.0033) Conclusion The study determined the relationships of grip strength performance and peak VO2, with the body composition indices in order to provide an overview of the mortal risks of an individual which might mediate the prognosis. Based on the relative independence of BSI with peak VO2 and grip strength performance, the unification of these parameters can help assess the overall health of an individual.

Differences in Aerobic and Anaerobic Capacity between Special Police Force Members and Elite Basketball Players

The goal of this research is to evaluate and compare the functional abilities of the special anti-terrorist unit from Serbia and professional basketball players. The idea is to determine whether members of the special unit police have high functional abilities and at what level are they compared to professional athletes. The sample of participants, for the purposes of this research, consisted of 162 respondents with an average age of 29.75±8.12 years who were classified into two groups. One group consisted of members of the SAF (special anti-terrorist force) (n=101) of average age 33.74±6.19 years and in other group were elite level professional basketball players from Serbia (n=57), of average age 22.39±4.25 from three Serbian clubs. To measure cardiorespiratory fitness, a cardiopulmonary exercises test (CPET) was performed on a treadmill (HPCOSMOS ®). Maximal oxygen consumption (VO2max), as a measure of aerobic capacity, was determined using the Quark CPET system (Cosmed®) by direct monitoring of gas exchange (oxygen and carbon dioxide). Aerobic ability of members of the Serbian SAF (special anti-teroristic force) can be considered excellent and almost close to the professional athletes, but statisticly lower (p&lt;0.05). Anaerobic capacity is also high and there is no difference in relation to basketball players (p&gt;0.05). These results can be explained by the selection of people who are chosen for this unit, which can be called very rigorous and equated with sports selection. The results of our study point to the fact that a high level of cardiorespiratory fitness is not only required by professional sports, but also by certain professions such as SAF.

Living high - training low model applied to C57BL/6J mice: Effects on physiological parameters related to aerobic fitness and acid-base balance

There is a scarcity of data regarding the acclimation to high altitude (hypoxic environment) accompanied by training at low altitude (normoxic conditions), the so-called “living high-training low” (LHTL) model in rodents. We aimed to investigate the effects of aerobic training on C57BL/6J mice living in normoxic (NOR) or hypoxic (HYP) environments on several parameters, including critical velocity (CV), a parameter regarded as a measure of aerobic capacity, on monocarboxylate transporters (MCTs) in muscles and hypothalamus, as well as on hematological parameters and body temperature. In each environment, mice were divided into non-trained (N) and trained (T). Forty rodents were distributed into the following experimental groups (N-NOR; T-NOR; N-HYP and T-HYP). HYP groups were in a normobaric tent where oxygen-depleted air was pumped from a hypoxia generator set an inspired oxygen fraction [FiO2] of 14.5 %. The HYP-groups were kept (18 h per day) in a normobaric tent for consecutive 8-weeks. Training sessions were conducted in normoxic conditions ([FiO2] = 19.5 %), 5 times per week (40 min per session) at intensity equivalent to 80 % of CV. In summary, eight weeks of LHTL did not promote a greater improvement in the CV, protein expression of MCTs in different tissues when compared to the application of training alone. The LHTL model increased red blood cells count, but reduced hemoglobin per erythrocyte was found in mice exposed to LHTL. Although the LHTL did not have a major effect on thermographic records, exercise-induced hyperthermia (in the head) was attenuated in HYP groups when compared to NOR groups.

ALTERAÇÕES DE VO2MAX OCASIONADAS PELO EXERCÍCIO AERÓBICO EM NADADORES

ABSTRACT Introduction The maximal oxygen consumption rate (VO2max) can directly reflect the body's aerobic metabolism and oxygen delivery system. This is a measure of aerobic capacity used to monitor swimmers’ levels and their strength and speed performance. Objective Verify the changes in VO2max when incorporating aerobic exercise training into swimmers’ regular training. Methods 12 volunteer swimmers were divided into two categories: strength training group and regular training group. Both groups performed a fitness test on the 200-meter track before starting the training. VO2 maximal was measured and worked out statistically to verify the results of this competition. The effects of aerobic exercise on the strength and competitive status of the athletes were investigated according to an updated literature review. Results There was a significant change in the maximal oxygen uptake of the athletes after the experimental protocol. The athletes in the strength training group increased their VO2 max compared to the regular training group. The results showed a significant difference in the VO2max index before and after strength training (P&lt;0.05). This suggests that strength training has a significant effect on maximal oxygen consumption. Conclusion Strength training interventions significantly affect athletes’ maximal oxygen consumption intensity and exercise capacity. The aerobic exercise intervention showed evidence of improving the competitive level of athletes. Level of evidence II; Therapeutic studies -investigation of treatment outcomes.

Macroregional Differences in Cardiorespiratory Fitness in Croatian Primary School Children

Purpose: Cardiorespiratory fitness (CRF) is an important indicator of health. Previous studies have shown that regional affiliation and the socioeconomic development of the area significantly influence the development of CRF. The aim of this research was to identify whether there are any differences in CRF among primary school children based on the macroregion in which they live. Methods: The study in-cluded 651 fourth-grade students from primary schools in the Republic of Croatia, aged 10.30±0.47 years. The sample of children was divided into three macro-regions of the Republic of Croatia (Continental, City of Zagreb, Adriatic). The CRF was assessed using the 20-meter shuttle run test. Results: The results indicate that children living in the region encompassing the city of Zagreb have significantly better results (45.77) in terms of maximal oxygen uptake (VO2max), which is used to assess CRF, compared to students coming from the Continental region (44.31). Students from the Adriatic macro-region have significantly better results (45.34) compared to those from the Conti-nental macro-region. There was no statistically significant difference observed between students from the city of Zagreb and the Adriatic macro-region. Conclusions: There is a great need to introduce physical exercise programs that affect the development of cardiorespiratory capacity in the Continental part of the Republic of Croatia, where it has been observed that students have a significantly lower level of cardiorespiratory fitness. There is a need to continue research that evaluates aerobic capacity in children and young people, and it should be based on direct measurements of aerobic capacity, by means of which more relevant data would be obtained, primarily on the values of maximum oxygen intake. Keywords: exercise physiology; physical fitness; relative age effects; students; young people.

Cardiopulmonary Exercise Testing in Athletes With Hypertrophic Cardiomyopathy

Patients with hypertrophic cardiomyopathy (HCM) have historically been restricted from athletic participation because of the perceived risk of sudden cardiac death. More contemporary research has highlighted the relative safety of competitive athletics with HCM. However, lack of published data on reference values for cardiopulmonary exercise testing (CPET) complicates clinical management and counseling on sports participation in the individual athlete. We conducted a single-center, retrospective cohort study to investigate CPET in athletes with HCM and clinical characteristics associated with objective measures of aerobic capacity. We identified 58 athletes with HCM (74% male, mean age 18±3years, mean left ventricular (LV) wall thickness 20±7mm). LV outflow tract obstruction was present in 22 (38%). A total of 15 (26%) athletes were taking a β blocker (BB), but only 4 (7%) reported exertional symptoms. Overall, exercise capacity was mildly reduced, with a peak myocardial oxygen consumption (peak VO2) of 37.9ml/min/kg (83% of predicted peak VO2). Both LV outflow tract obstruction and BB use were associated with reduced exercise capacity. Limited peak heart rate was more common in athletes taking BB (47% vs 9%, p=0.002). At a mean 5.6years follow-up, 5 patients underwent myectomy (9%), and 8 (14%) received an implantable cardioverter defibrillator (ICD) for primary prevention. One individual with massive LV hypertrophy experienced recurrent ICD shocks for ventricular fibrillation and underwent myectomy 7years after initial evaluation and was no longer participating in sports. There were no deaths over the follow-up period. In conclusion, the prognostic role of CPET remains unclear in athletes with HCM. Mildly reduced exercise capacity was common; however, reduced peak VO2 did not correlate with symptom status or clinical outcomes. A significant proportion went on to require myectomy and/or ICD, thus highlighting the need for close follow-up. These data provide some initial insight into the clinical evaluation of "real world" athletes with HCM; however, further study is warranted to help guide shared decision-making, return-to-play discussions, and the potential long-term safety of competitive athletic participation.

Measurement Properties of Aerobic Capacity Measures in Neuromuscular Diseases: A Systematic Review.

ObjectiveTo systematically evaluate the measurement properties of aerobic capacity measures in neuromuscular diseases.Data sourcesMEDLINE, EMBASE, SportDiscus and Web of Science Conference Proceedings Citation Index – Science were systematically searched from inception until 30 June 2021.Study selection and data extractionScreening, data extraction, risk of bias assessment and quality assessment were performed by 2 independent researchers. Studies were included if they evaluated measurement properties of aerobic capacity measures in adults with neuromuscular diseases. Risk of bias was assessed using the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. Results were pooled and the quality of the evidence was determined using a modified Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.Data synthesisNine studies including 187 participants were included in this review. Low quality of evidence was found for sufficient content validity of peak oxygen consumption through maximal exercise testing. Criterion validity of 4 out of 7 different measures to predict peak oxygen consumption was sufficient; however, quality of evidence was low or very low for all measures. No studies were found evaluating reliability or responsiveness.ConclusionThere was a lack of high-quality studies with sufficiently large sample sizes that evaluated the measurement properties of aerobic capacity measures in neuromuscular diseases.LAY ABSTRACTAerobic capacity (or cardiovascular endurance) is an important outcome measure in exercise intervention studies and pharmacological trials in neuromuscular diseases. To establish the effects of these interventions it is important to use outcome measures with good measurement properties. This means that outcome measures are accurate (valid), repeatable (reliable) and able to detect change over time (responsive). The aim of this study was to review the scientific literature regarding the measurement properties of aerobic capacity measures in neuromuscular diseases. Nine small studies (4–44 participants) reporting on the validity of 8 aerobic capacity measures were found. Five of these measures were judged as valid, but the quality of evidence was low. There were no studies evaluating reliability and responsiveness. Taken together, these results were considered insufficient to make recommendations. High-quality studies, with more participants and a focus on reliability and responsiveness, are required.

Evaluation of Two Training Programs Designed to Enhance Performance on the Army Combat Fitness Test Among ROTC Cadets.

Physical fitness is foundational to the U.S. Army as a component of combat readiness, and accurate assessment of readiness is imperative for mission success and soldiers' health and safety. To this end, the Army has developed the Army Combat Fitness Test (ACFT), which more accurately assesses these abilities and may aid development of a more combat-ready force. Reserve Officer Training Corps (ROTC) programs nationwide are often challenged by limited structured training time, as well as access to equipment and training space. Development and/or adaptation of a training program that addresses these limitations would benefit ROTC programs nationally. Therefore, the purpose of this study was to compare a standard military fitness training program to High-Intensity Functional Training (HIFT) in ROTC cadets. We hypothesized that a HIFT program would be more effective than the standard military program developed by the DoD on both ACFT performance and assessment of common Warrior Tasks and Battle Drills (WTBDs). This study was approved by the Institutional Review Board at Colorado State University (CSU). Participants were recruited from CSU's Army ROTC program. Before and upon completion of the training intervention, participants completed a battery of testing, conducted over three visits. The first visit consisted of body composition assessment and measurement of aerobic capacity (VO2max). Visit 2 was the ACFT, and Visit 3 was a "benchmark test" to assess WTBD performance. Participants then completed 10 weeks of group training. Once weekly, participants completed the Daily Analysis of Life Demands for Athletes (DALDA) survey to monitor the risk of overtraining. Responses to training and survey responses were examined using two-way analysis of variance (time × group) with repeated measures. Baseline characteristics were compared using Student's t-test to assess pre-intervention differences between groups. Pearson product correlations were used to test relationships between ACFT performance, body composition, and performance on the benchmark assessment. The significance level alpha was set at P < .05. Twenty-five men and 10 women competed the study (n = 35). Mean age was 19.8 ± 1.3 years, range 18-23. There were no significant changes in absolute or relative VO2max within or between groups. We found no difference in body mass, but did find a small but statistically significant favorable change in body composition, with no difference between groups. Overall ACFT scores and scores in five of the six events increased significantly across both groups, with no significant differences between groups. For the benchmark test, there was no significant difference between pre- and post-intervention benchmark scores, time to completion, 1,600-m ruck time, or accuracy. DALDA survey results indicate no apparent risk for overtraining. Three 60-minute sessions per week of moderate-high-intensity training elicited improvements in ACFT scores, with no statistically significant differences between training programs. For this population of ROTC cadets, implementing a structured training program with expert oversight appears to be effective. Based on the successes and unanticipated challenges encountered in this study, training programs that emphasize intensity, train a wide variety of movements, maximize adherence, and are adaptable to a variety of situations are likely to be successful at improving ACFT scores.

Oxygen uptake efficiency slope in community-dwelling ambulant stroke survivors during walking and stair climbing: a cross-sectional study

ABSTRACT Background Oxygen uptake efficiency slope during submaximal tests has been proposed as a more appropriate measure of aerobic capacity after suffering a stroke, since some individuals cannot tolerate maximal exercise testing. However, it has not yet been investigated whether the oxygen uptake efficiency slope is able to differentiate between healthy individuals and those who have suffered a stroke. Objectives To compare the oxygen uptake efficiency slope during walking and stair climbing between stroke survivors and age- and sex-matched healthy controls. Methods This is a cross-sectional study in which 18 individuals who had suffered a stroke (stroke survivors) and 18 healthy controls matched for sex and age were included. Oxygen consumption and minute ventilation were collected breath-by-breath during walking (6-min Walk Test) and stair climbing. The oxygen uptake efficiency slope was estimated by the slope of the line obtained through linear regression. Results The stroke survivors had a lower oxygen uptake efficiency slope during the 6-min Walk Test than the healthy controls (MD 498, 95% CI 122 to 873, p = .01). The between-group difference for the Stair Test was smaller and not statistically significant (MD 349, 95%CI −73 to 772, p = .10). Conclusions Stroke survivors had lower oxygen uptake efficiency slope during the performance of the 6-min Walk Test when compared to sex- and age-matched healthy controls. This suggests that stroke survivors have worse cardiopulmonary capacity.

Maturational effect on physical capacities and anabolic hormones in under-16 elite footballers: a cross-sectional study

PurposeThe purposes of this study were to describe the fitness and hormonal levels according to playing time (PT) (i.e., PT during season less (PT1) or more (PT2) than 50% of the total time) and maturation level (ML) (i.e., normal (ML1) and early maturity levels (ML2)), and to analyze the differences between groups for the measures of aerobic capacity, anaerobic power, power performance, and hormonal concentrations.MethodsTwenty-four youth footballers of a U16 team participated in this study. Anthropometric measures, maturity status, growth hormone, insulin-like growth factor (IGF-1), maximal oxygen uptake, fatigue index, and countermovement jump were collected.ResultsSignificant differences were found between both PT and ML groups for maturational status, aerobic capacity, power performance, and IGF1 concentrations. The interaction of PT and ML revealed significant differences for maturity offset and power performance. When using the skeletal age as a covariant, the previously significant differences found were reduced only to the fatigue index measure.ConclusionsThe response variables analyzed in the present study seem to be influenced by PT and ML. This must be considered when planning training, and coaches must be sensible to these effects as they may assume a preponderant role in PT.

Utilizing Low-Intensity Blood Flow Restriction Training to Improve Aerobic Capacity in Physically Active and Injured Individuals: A Critically Appraised Topic

Purpose: To determine if, in physically active individuals, low-intensity Blood Flow Restriction (BFR) training is more effective than training without BFR at improving measures of aerobic capacity. Methods: A database search was conducted for articles that matched inclusion criteria (minimum level 2 evidence, physically active participants, comparison of low-intensity BFR to no BFR training, comparison of pre-post testing with aerobic fitness or performance, training protocols &gt;2 weeks, studies published after 2010) by two authors and assessed by one using the PEDro scale (a minimum of 5/10 was required) to ensure level 2 quality studies that were then analyzed. Results: Four studies met all inclusion criteria. Three of the studies found significant improvements in aerobic capacity (VO2max) using BFR compared to no BFR. While the fourth study reported significant improvements in time to exertion (TTE) training with BFR, this same study did not find significant improvements in measures of aerobic capacity with BFR training. All compared BFR to non-BFR training. It was noted that high-intensity training without BFR was superior to both low-intensity training with and without BFR with respect to improvements in aerobic capacity. Conclusions: Moderate evidence exists to support the use of low-intensity BFR training to improve measures of aerobic capacity in physically active individuals over not using BRF. Clinicians seeking to maintain aerobic capacity in their patients who are unable, for various reasons, to perform high levels of aerobic activity may find low-intensity BFR training useful as a substitution while still receiving improvements in measures of aerobic capacity.

441-P: The Association between Time-in-Range %, Measured by Continuous Glucose Monitoring (CGM) and Physical and Functional Indices amongst Older People with Type 2 Diabetes: A Cross-Sectional Study

People with diabetes have an increased risk for mobility disability and a more rapid decline in muscle mass (sarcopenia) compared to those without diabetes. Studies have demonstrated an association between A1C and Sarcopenia. Less is known regarding the relationship with Time In Range (TIR). Aims: To assess among older people with diabetes type 2, the cross sectional association between: TIR and aerobic capacity, gait speed, strength, balance and frailty indices. Methods: A cross sectional study, conducted amongst people with diabetes over the age of 60. Participants were provided with a blinded CGM system- (I Pro2 carelink, Medtronic) for 1 week and underwent elaborate physical-functional assessment in the beginning and at the end of that week. The association between the % of time in range (TIR) and several physical indices was determined using linear regression. Results: This analysis pertains to 81 men and women. After adjustment for age and gender, a 1% higher TIR (70-180) was associated with a 0.246 higher score on the 6-minute walk score, a measure of aerobic capacity and endurance (P-value=0.019) and 0.212 lower score on the Timed Up and Go(TUG), a measure of fall risk and balance (P-value=0.045). Conclusion: Higher % TIR is associated with better scores on indices of aerobic capacity and a measure predicting falls. Future studies are needed in order to elucidated if glucose levels are merely a marker of disease severity, or if there is possibly a causal relationship. Disclosure Y. Basson-shleymovich: None. T. Cukierman-yaffe: Advisory Panel; Self; AstraZeneca, Research Support; Self; Medtronic, MSD Corporation, Speaker’s Bureau; Self; Eli Lilly and Company, Medtronic, MSD Corporation, Novo Nordisk, Sanofi. T. Yahalom-peri: None. M. Azmon: None. N. Peltz-sinvani: None. Funding European Foundation for the Study of Diabetes; Medtronic

Prediction of track performance in competitive BMX riders using laboratory measures

Identifying key physiological factors is essential in cycling; however, the unique nature of BMX decreases the validity and transferability of research findings from other cycling disciplines. Therefore, this study highlighted the physical and physiological characteristics of BMX riders that could influence track performance. Fifteen sub-elite BMX riders (male n = 12; age 18.3 ± 3.3 and female n = 3; 17.7 ± 5.7 years) undertook a battery of laboratory tests on three different occasions, including body composition, upper and lower body strength, flexibility, sprint and aerobic capacity measures. On a separate day, participants completed three full lap sprints on an outdoor BMX track. Correlation and multiple linear regression analyses were performed to develop predictive models of performance across the laboratory tests and race time. The final model indicated power to weight ratio, relative back-leg-chest strength and arm span explained ~87% of the variability in finish time (adjusted R2 = 0.87, p &lt; .01). These findings highlighted the importance of a multidimensional approach for developing BMX race performance. Coaches should prioritise these variables in their training programs and selection of future talents. However, further physiological and biomechanical investigation is needed to validate current findings, particularly among elite riders.

Metabolomics of Aerobic Exercise in Chronic Stroke Survivors: A Pilot Study

BackgroundUnderstanding the metabolic response to exercise may aid in optimizing stroke management. Therefore, the purpose of this pilot study was to evaluate plasma metabolomic profiles in chronic stroke survivors following aerobic exercise training. MethodsParticipants (age: 62 ± 1 years, body mass index: 31 ± 1 kg/m2, mean ± standard error of the mean) were randomized to 6 months of treadmill exercise (N = 17) or whole-body stretching (N = 8) with preintervention and postintervention measurement of aerobic capacity (VO2peak). Linear models for microarray data expression analysis was performed to determine metabolic changes over time, and Mummichog was used for pathway enrichment analysis following analysis of plasma samples by high-performance liquid chromatography coupled to ultrahigh resolution mass spectrometry. ResultsVO2peak change was greater following exercise than stretching (18.9% versus −.2%; P < .01). Pathway enrichment analysis of differentially expressed metabolites results showed significant enrichment in 4 pathways following treadmill exercise, 3 of which (heparan-, chondroitin-, keratan-sulfate degradation) involved connective tissue metabolism and the fourth involve lipid signaling (linoleate metabolism). More pathways were altered in pre and post comparisons of stretching, including branched-chain amino acid, tryptophan, tyrosine, and urea cycle, which could indicate loss of lean body mass. ConclusionsThese preliminary data show different metabolic changes due to treadmill training and stretching in chronic stroke survivors and suggest that in addition to improved aerobic capacity, weight-bearing activity, like walking, could protect against loss of lean body mass. Future studies are needed to examine the relationship between changes in metabolomic profiles to reductions in cardiometabolic risk after treadmill rehabilitation.

Are Aerobic Programs Similar in Design to Cardiac Rehabilitation Beneficial for Survivors of Stroke? A Systematic Review and Meta-Analysis.

BackgroundSurvivors of stroke face movement disability and increased cardiovascular disease and stroke risk. Treatment includes rehabilitation focused on functional movement with less emphasis on aerobic capacity. After rehabilitation, survivors of stroke must self‐manage activity with limited appropriate community programs. Lack of structured activity contributes to sedentary behavior. The objective of this systematic review and meta‐analysis is to review aerobic programs for stroke survivors similar in activity and dosage to cardiac rehabilitation programs to determine their efficacy for improving aerobic and walking capacity.Methods and ResultsPreferred Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines were used to review 5 databases. Group interventions for survivors of stroke with a primary aerobic component and dosage from 18 to 36 visits over 8 to 18 weeks (matching cardiac rehabilitation requirements in the United States) were included. The 6‐minute walk test, maximal oxygen consumption (VO2) peak, and walking speed were included as measures of aerobic capacity. Summary effect sizes and outcome measure mean differences were calculated for preintervention to postintervention, and summary effect sizes were calculated for preintervention to follow‐up. Activity type and initial 6‐minute walk test moderator analyses were performed. Nineteen studies with 23 eligible groups were selected. Survivors of stroke improved their composite aerobic capacity with an effect size of 0.38 (95% CI, 0.27–0.49). Studies including 6‐minute walk test demonstrated a pooled difference in means of 53.3 m (95% CI, 36.8–69.8 m). Follow‐up data were inconclusive.ConclusionsSurvivors of stroke benefit from aerobic programs with similar dosing to cardiac rehabilitation in the United States. The potential integration into existing programs could expand the community exercise options.

Ability to Predict Impending Volitional Exhaustion Based on Aerobic Capacity

Maximal relative oxygen consumption (VO2max), assessed via a treadmill test to volitional exhaustion, is the foremost measure of aerobic capacity in healthy, recreationally active young adults. Habitual exercise may improve the ability to perceive exercise difficulty and predict impending exhaustion. PURPOSE: The primary aim of this investigation was to determine if a correlation existed between VO2max and time to test termination after participants indicated they were 30 s from volitional exhaustion. A secondary aim was to ascertain if participants more accurately predicted impending exhaustion during a repeated trial. METHODS: Participants completed a familiarization trial to minimize learning effects and determine treadmill speed for maximal testing. During the familiarization trial, participants self-selected a zero-grade jogging speed associated with a value of 12-13 on Borg’s 6-20 RPE scale when steady-stated. This speed was used during two maximal tests separated by 36-72 h. During maximal testing, grade was increased 2% every two minutes until volitional exhaustion. VO2max was measured as a 15-breath moving average via a metabolic cart. Participants were instructed before and during testing to tap on the treadmill when they perceived themselves to be 30 s from volitional exhaustion. RESULTS: Thirteen (Females: 8, Males: 5) recreationally active individuals (20.7 ± 1.4 yrs., 72.4 ± 12.3 kg) completed the protocol. Mean VO2max during session 1 (10.00 ± 2.46 min) was 47.0 ± 7.4 ml⋅kg-1⋅min-1, and time to test termination after the tap was 36.2 ± 7.4 s. Mean VO2max during session 2 (10.08 ± 2.38 min) was 47.5 ± 7.7 ml⋅kg-1⋅min-1, and time to test termination after the tap was 40.0 ± 18.5 s. No significant correlation was detected between VO2max and time to test termination after the tap in session 1 (r = -.032, p = .917) or session 2 (r = .315, p = .295). A dependent t-test (t(12) = -.800, p = .439) did not reveal significant differences in time to test termination after the tap between session 1 and session 2. CONCLUSIONS: Aerobic capacity did not affect the ability of healthy, recreationally active young adults to predict impending volitional exhaustion during maximal treadmill running. Time to test termination after the tap did not significantly change during a repeated trial.

The Effects of Sleep Loss on Military Physical Performance.

As part of both training and active service, military members can be exposed to prolonged periods of sleep loss. Given the extent of physical and cognitive performances viewed as critical to successful military performance, such sleep disruption may present risk to health and performance. The primary aim of this narrative review was to investigate evidence on the effect of inadequate sleep on measures of aerobic capacity, anaerobic capacity, muscular strength and muscular endurance in military personnel. Sleep loss appears to have the greatest negative impact on aerobic capacity, muscular endurance and military-specific performance in military populations. The findings showed varied results for handgrip strength and anaerobic capacity, with sleep loss inducing a decrease in mean power of the upper body. In comparison to other measures of performance, lower-body muscular strength appeared to be resilient to sleep restriction. However, due to the limited evidence and inter-individual variability in results there is no clear consensus on the specific volume of sleep loss that induces significant or meaningful performance decrements. The difficulties of conducting well-designed and -controlled interventions in military populations are appreciated. However, due to the low quality of reporting and lack of control for confounders (i.e. physical activity, load carriage, prior sleep debt, motivation and energy intake) in the majority of studies, it is difficult to establish the relationship between sleep loss and physical performance in military populations.

Enhanced Strength, Power, Work Capacity, and Fatigue Resistance in High Intensity Functional Training Athletes

Measures of aerobic capacity, strength, fatigue, and power in athletes who specialize in either strength or endurance are relatively well understood. However, these measures in athletes who participate in high intensity functional training (HIFT) are comparatively unknown.PURPOSETo assess differences in aerobic capacity (VO2max), peak power (PP), end power (EP), strength (N.m), and fatigue (%change) in recreational athletes from Powerlifting and Olympic Lifting (STR), Cross Country (END) and HIFT backgrounds.METHODSTwenty‐one individuals from the three different training backgrounds were recruited (STR = 7, END = 7, HIFT = 7). Participants completed an incremental ramp, 30W/minute maximal cycle ergometer test to determine VO2max and gas exchange threshold (GET), and a 3‐minute all out sprint cycling test (3MAOT) to determine peak power (PP) and end power (EP). PP was determined as the maximal power out during the first 6s of the 3MAOT, and EP was calculated as the average power output during the last 30s. To determine strength, participants completed a maximal voluntary contraction (MVC) of the knee extensors on a Biodex at 90°, 75°, and 60° of knee flexion. A triaxial accelerometer was placed on the right vastus lateralis to measure fatigue as the %change in movement during 11‐minutes of continuous electrical stimulation separated by 30‐seconds of rest at the 9‐minute mark. Electrical stimulation consisted of doublets at a 5Hz train rate. Accelerometry data were digitally filtered with low‐pass filter at 40Hz cut off (4th order; Butterworth). Data were analyzed using a repeated measures ANOVA with results presented as mean and SD.RESULTSVO2max was significantly different between all groups (p &lt; 0.01). PP was significantly higher in STR and HIFT compared to END (p &lt; 0.05), but not between STR and HIFT. EP was significantly lower in STR compared to END and HIFT (p &lt; 0.01), but not between END and HIFT. The %change in STR during the fatigue test was significantly higher than the change observed in END and HIFT (p &lt; 0.05) but not between END and HIFT, indicating STR were more prone to fatigue than the other groups. The angle at which STR and HIFT recorded their highest peak torque was at 90° of knee flexion, whereas END peaked at 75°. Torque production at all three angles was significantly lower in END compared to STR and HIFT (p &lt; 0.05) but was not significantly different at any angle between STR and HIFT. See table 1 for mean results comparisons.ConclusionTo our knowledge, this study is the first to compare performance related measures in HIFT athletes to traditional strength and endurance specialists. The results indicate that HIFT athletes can exert similar power outputs and absolute strength compared to strength specialists but exhibit a resistance to fatigue that is comparable to endurance specialists. imageThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.