Greater Aerobic Capacity Research Articles

Intraspecific variation among Chinook Salmon populations indicates physiological adaptation to local environmental conditions.

Understanding interpopulation variation is important to predicting species responses to climate change. Recent research has revealed interpopulation variation among several species of Pacific salmonids; however, the environmental drivers of population differences remain elusive. We tested for local adaptation and countergradient variation by assessing interpopulation variation among six populations of fall-run Chinook Salmon from the western United States. Juvenile fish were reared at three temperatures (11, 16 and 20°C), and five physiological metrics were measured (routine and maximum metabolic rate, aerobic scope, growth rate and critical thermal maximum). We then tested associations between these physiological metrics and 15 environmental characteristics (e.g. rearing temperature, latitude, migration distance, etc.). Statistical associations between the five physiological metrics and 15 environmental characteristics supported our hypotheses of local adaptation. Notably, latitude was a poor predictor of population physiology. Instead, our results demonstrate that populations from warmer habitats exhibit higher thermal tolerance (i.e. critical thermal maxima), faster growth when warm acclimated and greater aerobic capacity at high temperatures. Additionally, populations with longer migrations exhibit higher metabolic capacity. However, overall metabolic capacity declined with warm acclimation, indicating that future climate change may reduce metabolic capacity, negatively affecting long-migrating populations. Linking physiological traits to environmental characteristics enables flexible, population-specific management of disparate populations in response to local conditions.

Fatness, fitness and the aging brain: A cross sectional study of the associations between a physiological estimate of brain age and physical fitness, activity, sleep, and body composition

IntroductionChanges in brain structure and function occur with aging. However, there is substantial heterogeneity both in terms of when these changes begin, and the rate at which they progress. Understanding the mechanisms and/or behaviors underlying this heterogeneity may allow us to act to target and slow negative changes associated with aging. MethodsUsing T1 weighted MRI images, we applied a novel algorithm to determine the physiological age of the brain (brain-predicted age) and the predicted age difference between this physiologically based estimate and chronological age (BrainPAD) to 551 sedentary adults aged 65 to 84 with self-reported cognitive complaint measured at baseline as part of a larger study. We also assessed maximal aerobic capacity with a graded exercise test, physical activity and sleep with accelerometers, and body composition with dual energy x-ray absorptiometry. Associations were explored both linearly and logistically using categorical groupings. ResultsVisceral Adipose Tissue (VAT), Total Sleep Time (TST) and maximal aerobic capacity all showed significant associations with BrainPAD. Greater VAT was associated with higher (i.e,. older than chronological) BrainPAD (r = 0.149 p = 0.001)Greater TST was associated with higher BrainPAD (r = 0.087 p = 0.042) and greater aerobic capacity was associated with lower BrainPAD (r = −0.088 p = 0.040). With linear regression, both VAT and TST remained significant (p = 0.036 and 0.008 respectively). Each kg of VAT predicted a 0.741 year increase in BrainPAD, and each hour of increased TST predicted a 0.735 year increase in BrainPAD. Maximal aerobic capacity did not retain statistical significance in fully adjusted linear models. DiscussionAccumulation of visceral adipose tissue and greater total sleep time, but not aerobic capacity, total daily physical activity, or sleep quantity and/or quality are associated with brains that are physiologically older than would be expected based upon chronological age alone (BrainPAD).

Physical Condition and Risk of Hospitalization and Polypharmacy in Older Adults.

Hospitalization in older population leads to a decline in physical function, physical condition, and independency. However, a scarce number of studies has addressed the effect of being in good physical condition on the risk of hospitalization and polypharmacy in older people. Therefore, this study aims to examine the relationship between physical condition and other health factors, and the incidence of hospitalization and polypharmacy in Spanish older persons. For this cross-sectional study we recruited 102 institutionalized persons aged 80 years or older, who were being treated at three primary care centers. The data collected were number of hospitalizations and medications, dietary habits, nutrition status, quality of life, independence in activities of daily life, physical performance, and associated genotype data. Scoring higher in the tests Chair stand and 8-Foot Up-and-go was found associated with reduced risks of hospitalization (odds ratio [OR] = 0.45 [95% CI = 0.2-0.99]; OR 0.32 [95% CI = 0.12-0.86]) and polypharmacy (OR = 0.36 [95% CI = 0.16-0.8]; OR = 0.28 [95% CI = 0.1-0.78]). The number of medications was also lower in individuals with a greater aerobic capacity and activities of daily life independence (OR = 0.28 [95% CI = 0.1-0.78]; OR = 0.37 [95% CI = 0.16-0.82]). No associations were found with the remaining physical performance tests or other factors assessed. Our findings point to benefits of greater strength, balance, and aerobic capacity in terms of reducing the risk of hospitalization and polypharmacy.

Short- and long-distance avian migrants differ in exercise endurance but not aerobic capacity

BackgroundMigratory birds differ markedly in their migration strategies, particularly those performing short- versus long-distance migrations. In preparation for migration, all birds undergo physiological and morphological modifications including enlargement of fat stores and pectoral muscles to fuel and power their flights, as well as cardiovascular and biochemical adjustments that improve lipid and oxygen delivery and uptake by flight muscles. While the magnitude of these changes varies in relation to migration strategy, the consequence of these variations on aerobic performance is unknown. We tested whether the aerobic performance of four Old-world flycatcher species (Muscicapidae) varied according to migration strategy by comparing minimum resting metabolic rates (RMRmin), exercise-induced maximum metabolic rates (MMR), and exercise endurance times of short-distance and long-distance migratory birds.ResultsAs expected, RMRmin did not vary between short-distance and long-distance migrants but differed between the species within a migration strategy and between sexes. Unexpectedly, MMR did not vary with migration strategy, but MMR and blood haemoglobin content were positively related among the birds tested. Exercise endurance times differed substantially between migration strategies with long-distance migrants sustaining exercise for > 60% longer than short-distance migrants. Blood haemoglobin content had a significant positive effect on endurance among all birds examined.ConclusionsThe lack of difference in RMRmin and MMR between long- and short-distance migrants during this stage of migration suggests that the attributes favouring the greater aerobic endurance of long-distance migrants did not come at the expense of increased maintenance costs or require greater aerobic capacity.

Hill Runner's Physiology, Performance and Nutrition: A Descriptive Study.

Objectives: The aim of this descriptive study was to characterise anthropometric variables, aerobic capacity, running performance and energy intake and expenditure of hill runners in free-living conditions, and to investigate the relationship between age, anthropometric variables, aerobic capacity and running performance.Methods: Twenty-eight hill runners participated in this study (17 males and 11 females; aged 18–65 years). Body fat percentage estimate, sum of eight skinfolds (triceps, subscapular, biceps, iliac crest, supraspinale, abdominal, front thigh and medial calf) and maximal oxygen capacity (VO2max) were assessed in a laboratory setting. Participants also completed a timed hill run (Dumyat Hill, Scotland, ascent: 420 m, distance: 8 km) while wearing a portable gas analyzer to assess oxygen consumption (VO2). Energy intake and energy expenditure were assessed in free-living conditions over three consecutive days different from the testing days through self-reported food diaries and accelerometers.Results: VO2max assessed in the lab (51.2 ± 7.6 ml·min−1·kg−1) showed a weak negative relationship with age [rs(23) = −0.38, p = 0.08]. Neither body fat percentage (median 12.4; IQR 10.1–17.1) nor the sum of skinfolds (median 81.8; IQR 62.4–97.8 mm) correlated with age [rs(28) = 0.001, p = 0.10 and 26 rs(28) = −0.02, p = 0.94, respectively]. The observed intensity of the hill run was 89 ± 6% of the age predicted maximum heart rate and 87 ± 9% of the VO2max observed in the lab. Hill running performance correlated with VO2max [r(21) = 0.76, p < 0.001], age [rs(26) = −0.44, p = 0.02] and with estimated body fat percentage and sum of skinfolds [rs(26) = −0.66, p < 0.001 and rs(26) = −0.49, p = 0.01, respectively]. Energy intake negatively correlated with age [rs(26) = −0.43, p = 0.03], with the overall energy intake being significantly lower than the total energy expenditure (2273 ± 550 vs. 2879 ± 510 kcal·day−1; p < 0.001; d = 1.05).Conclusion: This study demonstrated that hill running performance is positively associated with greater aerobic capacity and negatively associated with increases in adiposity and age. Further, the study highlights that hill runners are at risk of negative energy balance.

Resilience of cardiac performance in Antarctic notothenioid fishes in a warming climate.

Warming in the region of the Western Antarctic Peninsula is occurring at an unprecedented rate, which may threaten the survival of Antarctic notothenioid fishes. Herein, we review studies characterizing thermal tolerance and cardiac performance in notothenioids - a group that includes both red-blooded species and the white-blooded, haemoglobinless icefishes - as well as the relevant biochemistry associated with cardiac failure during an acute temperature ramp. Because icefishes do not feed in captivity, making long-term acclimation studies unfeasible, we focus only on the responses of red-blooded notothenioids to warm acclimation. With acute warming, hearts of the white-blooded icefish Chaenocephalus aceratus display persistent arrhythmia at a lower temperature (8°C) compared with those of the red-blooded Notothenia coriiceps (14°C). When compared with the icefish, the enhanced cardiac performance of N. coriiceps during warming is associated with greater aerobic capacity, higher ATP levels, less oxidative damage and enhanced membrane integrity. Cardiac performance can be improved in N. coriiceps with warm acclimation to 5°C for 6-9 weeks, accompanied by an increase in the temperature at which cardiac failure occurs. Also, both cardiac mitochondrial and microsomal membranes are remodelled in response to warm acclimation in N. coriiceps, displaying homeoviscous adaptation. Overall, cardiac performance in N. coriiceps is malleable and resilient to warming, yet thermal tolerance and plasticity vary among different species of notothenioid fishes; disruptions to the Antarctic ecosystem driven by climate warming and other anthropogenic activities endanger the survival of notothenioids, warranting greater protection afforded by an expansion of marine protected areas.

Relationship Of Glucose Kinetics With Exercise Capacity, Body Composition, And Mitochondrial Function With Aging

Aging is commonly associated with decreases in aerobic capacity, skeletal muscle mass and function, as well as metabolic dysregulation including insulin resistance. PURPOSE: We sought to investigate relationships between these aforementioned hallmark traits of aging. METHODS: Young healthy adults (24-34 years; n=16; 7F/9M; BMI: 25±3 kg/m2) and older adults (65-79 years; n=39; 20F/19M; BMI: 27±4 kg/m2) were recruited as a part of this investigation. Subjects completed a graded maximal exercise test (VO2peak) on a treadmill, a dual-energy X-ray absorptiometry scan, measurement of single-leg knee extension power, a mixed meal tolerance test upon which blood glucose was monitored throughout the next 5 hours, and a resting vastus lateralis biopsy to measure ATP production from permeabilized muscle fibers. RESULTS: Young had a 38% greater aerobic capacity and 45% greater knee extensor maximal power/lean mass. Fasting plasma glucose was lower (P<0.05) in young (86±7 mg/dL vs. 93±8 mg/dL in young and old, respectively), as well as young had 31% lower plasma glucose area above baseline (AAB) in response to the mixed meal tolerance test compared to old (P<0.05). No differences between young and old were observed in lean body mass, fasting plasma insulin, or maximal mitochondrial ATP production (state III). Interestingly, AAB was not significantly correlated with phenotypic characteristics (BMI or lean body mass), fasting plasma glucose or insulin, or maximal ATP production. However, AAB was significantly (P<0.05) inversely correlated with VO2peak relative to body mass (r = -0.38) and knee extensor power/lean mass (r = -0.47). CONCLUSIONS: These data suggest that glucose tolerance may be a function of skeletal muscle quality rather than total lean mass. However, the inverse relationship with AAB and measurements of whole body functional tests do not appear to be related mitochondrial energy production, suggesting the need for further mechanistic investigations. Supported by NIH grant R01AG054454

Physical Qualities Discriminate Playing Level In Elite Youth Hockey Players

PURPOSE: The purpose of this study was to compare physical test results between playing levels and positions in youth elite hockey players. METHODS: Subjects (n=49) came from 3 distinct levels: Bantam AAA Relève (the lowest, n=16), Bantam AAA Major (the second highest, n=17), and Midget Espoir (the highest, n=16). Physical characteristics and qualities were measured. The stationary broad jump was utilized to measure lower-body power. Jump distance was measured from toes to the closest landed heel. The best of two attempts was marked as the final score. The seated medicine ball throw was utilized to measure upper-body power. Throw distance was measured from the back of the wall to where the ball first made contact with the ground. The 20-meter shuttle run test was utilized to measure aerobic capacity. VO2max was estimated from the last level completed with the Leger-Lambert formula. Results are presented as mean and standard deviation. A single factor (level or position) ANOVA and when significant a post-hoc analysis was also performed by using the least significant difference (LSD) for pairwise comparisons between groups tests results. Statistical significance was set at p<0.05. Analysis was conducted with IBM SPSS Statistics for Windows version 25. RESULTS: Hockey players of the two higher levels were significantly (p<0.05) taller (1.73 ± 0.08m and 1.74 ± 0.08m, respectively, vs 1.63 ± 0.09m), heavier (66.68 ± 8.09m and 68.60 ± 10.96m respectively vs 53.52 ± 8.73m), jumped further (2.25 ± 0.13m and 2.26 ± 0.12m respectively vs 2.01 ± 0.20m), and had greater aerobic capacity (3.87 ± 0.52 L/min and 3.84 ± 0.57 L/min respectively vs 2.96 ± 0.49 L/min) than the hockey players from the lower level. However, the higher level players, scored lower than the middle level at the seated medicine ball throw (3.74 ± 0.49m vs 4.60 ± 0.48m), even though the middle level scored higher than the lower level (4.60 ± 0.48m vs 3.49 ± 0.53m). Results also show that the goaltenders were significantly taller than the other hockey players (1.77 ± 0.10m vs 1.72 ± 0.08m for defensemen and 1.67 ± 0.10m for forwards). CONCLUSION: The stationary broad jump, the seated medicine ball throw and the 20 meters shuttle run are field tests that could be used in order to discriminate playing levels in youth elite hockey players.

The Biology of Sex and Sport.

Sex and gender are not the same. Sex is defined by the human genotype and pertains to biologic differences between males and females. Gender is a fluid concept molded by self-perception, social constructs, and culturally laden attitudes and expectations of men and women. In general, males have longer limb levers, stronger bones, greater muscle mass and strength, and greater aerobic capacity. Females exhibit less muscle fatigability and faster recovery during endurance exercise. Physiologic sex-based differences have led to an average performance gap of 10% that has remained stable since the 1980s. The performance disparity is lowest for swimming and highest for track and field events. The International Olympic Committee currently mandates that female athletes with differences of sex development, or intersex traits, and transgender female athletes must limit their blood testosterone to <10 nmol/L for 12 months to be eligible for competition in the female classification.

DOES HABITUAL PHYSICAL ACTIVITY LEVEL INFLUENCE AEROBIC CAPACITY AND HEART RATE VARIABILITY IN POSTMENOPAUSAL WOMEN?

ABSTRACT The aim of this research was to verify whether habitual physical activity level (HPAL) influences aerobic capacity and parasympathetic activity at rest in postmenopausal women. Thirty postmenopausal women participated in the study (59.3 ± 5.3 years old; 1.58 ± 0.06 m; 64.5 ± 9.6 kg; 25.6 ± 3.1 body mass index; 27 ± 5%fat). The women were divided into two groups based on the median pedometer step count of HPAL (G1 = HPAL) and submitted to the incremental shuttle walking test (ISWT) and analysis of heart rate variability (HRV) at rest. Substantial differences were found between G1 and G2 for step count (p = 0.0001); effect size (ES) = 2.55), ISWT distance (p = 0.0002; ES = 2.24), root mean square of successive difference (RMSSD) (p = 0.0001; ES = 1.56), and high-frequency band (p = 0.0001; ES = 1.31). In conclusion, postmenopausal women with higher HPAL have greater aerobic capacity and parasympathetic modulation of HRV.

Nature Versus Nurture: Have Performance Gaps Between Men and Women Reached an Asymptote?

Men outperform women in sports requiring muscular strength and/or endurance, but the relative influence of "nurture" versus "nature" remains difficult to quantify. Performance gaps between elite men and women are well documented using world records in second, centimeter, or kilogram sports. However, this approach is biased by global disparity in reward structures and opportunities for women. Despite policies enhancing female participation (Title IX legislation), US women only closed performance gaps by 2% and 5% in Olympic Trial swimming and running, respectively, from 1972 to 1980 (with no change thereafter through 2016). Performance gaps of 13% in elite middistance running and 8% in swimming (∼4-min duration) remain, the 5% differential between sports indicative of load carriage disadvantages of higher female body fatness in running. Conversely, sprint swimming exhibits a greater sex difference than sprint running, suggesting anthropometric/power advantages unique to swim-block starts. The ∼40-y plateau in the performance gap suggests a persistent dominance of biological influences (eg, longer limb levers, greater muscle mass, greater aerobic capacity, and lower fat mass) on performance. Current evidence suggests that women will not swim or run as fast as men in Olympic events, which speaks against eliminating sex segregation in these individual sports. Whether hormone reassignment sufficiently levels the playing field in Olympic sports for transgender females (born and socialized male) remains an issue to be tackled by sport-governing bodies.

Photobiomodulation increases mitochondrial citrate synthase activity in rats submitted to aerobic training.

This study investigated the effects of photobiomodulation by low-laser laser therapy (LLLT) on the activities of citrate synthase (CS) and lactate dehydrogenase (LDH) and the anaerobic threshold (AT) in rats submitted to treadmill exercise. Fifty-four rats were allocated into four groups: rest control (RCG), rest laser (RLG), exercise control (ECG), and exercise laser (ELG). The infrared LLLT was applied daily on the quadriceps, gluteus maximum, soleus, and tibialis anterior muscles. Muscle samples (soleus, tibialis anterior, and cardiac muscles) were removed 48h after the last exercise session for spectrophotometric analysis of the CS and LDH. The CS activity (μmol/protein) in ELG (16.02 and 0.49) was significantly greater (P < 0.05) than RCG (2.34 and 0.24), RLG (6.25 and 0.17), and ECG (6.76 and 0.26) in the cardiac and soleus muscles, respectively. The LDH activity (in 1Mm/protein) in soleus muscle was smaller (P < 0.05) for ELG (0.33) compared to ECG (0.97), RLG (0.79), and RCG (1.07). For cardiac muscle, the LDH activity was smaller (P < 0.05) in ELG (1.38) compared to ECG (1.91) and RCG (2.55). The ECG and ELG showed increases in the maximum speed and a shift of the AT to higher effort levels after the training period, but no differences occurred between the exercised groups. In conclusion, the aerobic treadmill training combined with LLLT promotes an increase of oxidative capacity in this rat model, mainly in muscles with greater aerobic capacity.

Physiological Attributes of an NCAA Intercollegiate Triathlon Team

The NCAA recently added women’s triathlon to its “emerging sports” program. Prior literature has focused on the attributes of highly trained, junior elite, and recreational triathletes and comparative benchmark data of varsity intercollegiate triathletes are currently unavailable. PURPOSE: To examine physiological attributes of NCAA varsity intercollegiate triathletes. METHODS: Six male (age 19.0 ± 1.1 yrs) and 3 female (age 18.7 ± 0.6 yrs) varsity intercollegiate triathletes underwent physiological testing during maximal treadmill run and cycling protocols, and a 1km pool swim time trial performed on separate days. Physiological indices assessed for each protocol are presented in the table. Data were compared to determine sex differences between athletes in the present study and versus highly trained, junior elite and recreational triathletes as reported in the literature. RESULTS: Group differences were observed between males and females for the run and cycle tests and for the 1km swim.Table: No title available.Participants had lower VO2peak values than highly trained (male 73.8 ± 1.6, female 59.7 ± 5.0 ml/kg/min; p ≤ 0.05) and junior elite triathletes for run (male 73.2 ± 7.4 ml/kg/min; p ≤ 0.05) and bike (male 68.2 ± 7.4 ml/kg/min; p ≤ 0.05) but had greater aerobic capacities than recreational triathletes for run (male 62.9 ± 7.2 ml/kg/min; p ≤ 0.05) and bike (male 59.6 ± 5.4 ml/kg/min; p ≤ 0.05). Mean (± SD) 1km swim times for male and female participants were significantly slower than national performance standards for 19 yr old triathletes (male 11:59.0 and female 12:48.0; p ≤ 0.05). CONCLUSION: Our findings are the first to present physiological attributes of NCAA varsity intercollegiate triathletes and indicate favorable VO2peak values compared to recreational triathletes, but not to highly trained or junior elite triathletes.

Physical Exercise for Late-Life Depression: Customizing an Intervention for Primary Care.

To identify which individual- and context-related factors influence the translation into clinical practice of interventions based on physical exercise (PE) as an adjunct to antidepressants (AD) for the treatment of late-life major depression (LLMD). Secondary analysis of a randomized controlled trial. Primary care with psychiatric consultation-liaison programs (PCLPs)-organizational protocols that regulate the clinical management of individuals with psychiatric disorders. Individuals aged 65 and older with major depression according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (N = 121). Participants with LLMD were randomized to AD (sertraline) or AD plus PE (AD + PE). Participant characteristics that were associated with greater effectiveness of AD + PE (moderators) were identified, and effect sizes were calculated from success rate differences. Whether the characteristics of the study setting influenced participant flow and attendance at exercise sessions was then explored, and primary care physicians (PCPs) were surveyed regarding their opinions on PE as a treatment for LLMD. The following participant characteristics were associated with greater likelihood of achieving remission from depression with AD + PE than with AD alone: aged 75 and older (effect size 0.32), polypharmacy (0.35), greater aerobic capacity (0.48), displaying psychomotor slowing (0.49), and less-severe anxiety (0.30). The longer the PCLP had been established at a particular center, the more individuals were recruited at that center. After participating in the study, PCPs expressed positive views on AD + PE as a treatment for LLMD and were more likely to use this as a therapeutic strategy. The combination of PE and sertraline could improve the management of LLMD, especially when customized for individuals with specific clinical features. Liaison programs might influence the implementation of similar interventions in primary care, and PCPs viewed them positively.

Greater Vo2peak Is Associated With Deoxygenation Amplitude, But Not Deoxygenation Kinetics, Across The Active Muscles

It is axiomatic that individuals with a greater peak O2 uptake (Vo2peak) sustain greater perfusive and diffusive O2 conductance across the active musculature in toto. However, it is unclear how these O2 conductances are regulated among knee extensor muscles that are spatially heterogeneous in blood flow, fiber type, and motor unit recruitment, in individuals whom vary in Vo2peak. PURPOSE: Using quantitative near infrared spectroscopy (NIRS) from rest to maximal exercise, we tested the hypotheses that with greater Vo2peak the vastus lateralis (VL) and rectus femoris (RF) muscles would evince: 1) a greater increase in deoxyhemoglobin concentration ([HHb], an index of O2 extraction) and [hemoglobin] ([tHb], an index of diffusive O2 potential); and 2) a right-shift in the [HHb] half-time (f50, an index of relative perfusion); together suggesting that a greater aerobic capacity is associated with improvements in both perfusive and diffusive O2 transport. METHODS: 22 healthy subjects completed ramp incremental cycling exercise (20 W·min-1) to the limit of tolerance. Pulmonary Vo2 was measured breath-by-breath. [HHb] and [tHb] were quantified in the VL and RF by time-resolved NIRS. Each NIRS profile was modeled with a sigmoid (y = B + A / [1 + exp-(-c+dx)], B is baseline, A is amplitude, c is a constant dependent on d, d is the slope of the sigmoid, and f50 = c/d). RESULTS: Vo2peak ranged from 37.7 to 66.4 ml·kg-1·min-1. Vo2peak was associated with the exercise-induced increase in [HHb] for both muscles (VL, r = 0.432; RF, r = 0.529; P < 0.05), and exercise-related increase in [tHb] for RF (r = 0.473, P < 0.05). However, Vo2peak did not correlate with f50 for [HHb]. CONCLUSIONS: As expected, greater Vo2peak during cycling was achieved, in part, via an increased capacity for O2 extraction in the knee extensors reflected in the greater amplitude for [HHb]. However, a greater capacity for diffusive O2 conductance (increase in [tHb]) to support increased O2 exchange, only related to Vo2peak in the RF muscle. These results support that a greater Vo2peak requires an increase in the maximal capacity for O2 conductance across the active musculature, while a regional change in the kinetics of O2 conductance at a given submaximal relative work rate is not an obligatory adaptation. Supported by JSPS-15K16476, 24247046, 26560362

Aerobic fitness, micronutrient status, and academic achievement in Indian school-aged children.

Aerobic fitness has been shown to have several beneficial effects on child health. However, research on its relationship with academic performance has been limited, particularly in developing countries and among undernourished populations. This study examined the association between aerobic fitness and academic achievement in clinically healthy but nutritionally compromised Indian school-aged children and assessed whether micronutrient status affects this association. 273 participants, aged 7 to 10.5 years, were enrolled from three primary schools in Bangalore, India. Data on participants’ aerobic fitness (20-m shuttle test), demographics, anthropometry, diet, physical activity, and micronutrient status were abstracted. School-wide exam scores in mathematics and Kannada language served as indicators of academic performance and were standardized by grade level. The strength of the fitness/achievement association was analyzed using Spearman’s rank correlation, multiple variable logistic regression, and multi-level models. Significant positive correlations between aerobic capacity (VO2 peak) and academic scores in math and Kannada were observed (P < 0.05). After standardizing scores across grade levels and adjusting for school, gender, socioeconomic status, and weight status (BMI Z-score), children with greater aerobic capacities (mL * kg-1 * min-1) had greater odds of scoring above average on math and Kannada exams (OR=1.08, 95% CI: 1.02 to 1.15 and OR=1.11, 95% CI: 1.04 to 1.18, respectively). This association remained significant after adjusting for micronutrient deficiencies. These findings provide preliminary evidence of a fitness/achievement association in Indian children. While the mechanisms by which aerobic fitness may be linked to academic achievement require further investigation, the results suggest that educators and policymakers should consider the adequacy of opportunities for physical activity and fitness in schools for both their physical and potential academic benefits.

Elimination of influences of the ACTN3 R577X variant on oxygen uptake by endurance training in healthy individuals.

To study the relationship between the ACTN3 R577X polymorphism and oxygen uptake (VO2) before and after exercise training. Police recruits (N=206, 25±4 y) with RR (n=75), RX (n=97), and XX (n=33) genotypes were selected. After baseline measures, they underwent 18 wk of running endurance training. Peak VO2 was obtained by cardiopulmonary exercise testing. Baseline body weight was not different among genotypes. At baseline, XX individuals displayed higher VO2 at anaerobic threshold, respiratory compensation point, and exercise peak than did RR individuals (P<.003). Endurance training significantly increased VO2 at anaerobic threshold, respiratory compensation point, and exercise peak (P<2×10(-6)), but the differences between XX and RR were no longer observed. Only relative peak VO2 exercise remained higher in XX than in RR genotype (P=.04). In contrast, the increase in relative peak VO2 was greater in RR than in XX individuals (12% vs 6%; P=.02). ACTN3 R577X polymorphism is associated with VO2. XX individuals have greater aerobic capacity. Endurance training eliminates differences in peak VO2 between XX and RR individuals. These findings suggest a ceiling-effect phenomenon, and, perhaps, trained individuals may not constitute an adequate population to explain associations between phenotypic variability and gene variations.

Estimation of Relationship between Maximal Oxygen Consumption and Repeated Sprint Ability of Male Handball Players

The purpose of the present study was to investigate the relationship between maximal oxygen consumption and repeated sprint ability of male university handball players. Twenty seven (27) male university handball players were selected from Department of Physical Education and Sports Sciences, Annamalai University, who voluntarily participated in this study (age: 21.62 ± 1.90 years; height: 172.07 ± 7.25 cm; body weight: 64.59 ± 9.92 kg). Multistage 20 m shuttle run test was used for the estimation of maximal oxygen uptake and total distance covered. Repeated sprint ability was measured by 7×30 meters sprint with 25 second recovery. The results of product moment correlation analysis showed significant correlation between maximal oxygen consumption with fatigue index (r = 0.965, p = 0.000), fast sprint time (r = 0.772, p = 0.000), slowest sprint time (r = 0.875, p = 0.000) and mean sprint time (r = 0.807, p = 0.000). The findings of the present study indicated significant negative correlation among maximal oxygen consumption and repeated sprint ability of male handball players. This clearly shows that players with greater aerobic capacity will have better repeated sprint ability.

Anthropometry, Somatotypes, and Aerobic Power in Ballet, Contemporary Dance, and DanceSport

This study compared anthropometric variables, somatotypes, and aerobic capacity between three groups of dancers: classical ballet dancers (M 33, F 56), contemporary dancers (M 28, F 109), and dancesport dancers (M 30, F 30). The assumption was that different functional requirements should produce differences in the anthropometric and aerobic capacity variables among the three groups. Anthropometric data for body mass index (BMI) and somatotypes were measured. Body fat percentage was measured by dual-energy x-ray absorptiometry. Maximal oxygen consumption and aerobic power were measured during an incremental treadmill test until exhaustion. Dancesport athletes were taller compared with same gender contemporary dancers (p<0.05). Female ballet dancers had a lower body mass and BMI compared with their contemporary dance and dancesport equivalents (p<0.001). There was significant difference between dance styles in endomorphy (F2,221 = 8.773, p<0.001) and mesomorphy (F2,221 = 21.458, p<0.001) scores. Dancesport dancers had significantly greater VO2max values (p<0.01). It was concluded that female contemporary dancers are generally more muscular than their ballet counterparts, while dancesport dancers are taller and heavier, less muscular, with slightly greater adioposity compared to the classical ballet dancers. Ballet dancers had the lowest body fat percentage, weight, and BMI values. Dancesport dancers had greater aerobic capacity than the ballet dancers. Based on this study, we conclude that dancers in these three styles differ in some aspects of anthropometric variables, somatotypes, and aerobic capacity, but we cannot say is it because of the training or selection or both.

The aerobic performance of trained and untrained handcyclists with spinal cord injury

The purpose of this study was to compare the cardiorespiratory response and mechanical efficiency (ME) of highly trained spinal cord injured (SCI) handcyclists with untrained SCI men. Ten trained handcyclists (≥ 2 years training) and ten untrained but physically active SCI men completed an incremental exercise test to exhaustion and a sub-maximal test (50 and 80 W) on an electromagnetically braked arm ergometer. The trained participants completed a questionnaire on their training and race performance over the past year, including average training volume (in kilometers), number of training sessions per week and best 20-km time trial. The trained SCI men had higher VO2 peak, peak power (p ≤ 0.001) and peak heart rate (p = 0.021) compared to the untrained SCI men. The trained men had higher (p ≤ 0.001) ME at 50 W (14.1 ± 2.0%) and 80 W (17.2 ± 2.6) compared to the untrained men (50 W; 12.5 ± 1.8 and 80 W; 15.7 ± 2.1). Peak power (r = -0.87, p = 0.001), VO2 peak (r = -0.67, p = 0.033) and ME (r = -0.58, p = 0.041) were negatively correlated with the participants best 20-km time trial. Multiple linear regression indicated peak power (p < 0.001) and VO2 peak (p = 0.021) were the best predictors (87%) of 20-km time trial performance. Highly trained SCI handcyclists have a greater aerobic capacity and ME compared to untrained SCI, and are able to reach their maximum age-predicted heart rate during an incremental exercise test. The best predictor of 20 km race performance in highly trained SCI handcyclists is peak power attained during an incremental exercise test.