ABSTRACT
Cardio respiratory endurance is the ability to exercise the entire body for extended periods of time without undue fatigue. A strong heart is necessary to supply oxygenated blood to the muscles of the body effectively. For the purpose of the study a group of 80 healthy adults were divided in four equals groups. Experimental groups 'A', 'B', 'C' and control group 'D' of 20 subjects each were compared in this study. The purpose of this study was to investigate the response of certain yogic practices and physical exercise programme on cardiorespiratory endurance and to assess their effectiveness as measured by nine minute run -walk test(AAPHER Health related physical ?tness test,1980).The analysis of data revealed that the three experimental groups trained by Exercise, yogic practices and combined exercise and yogic practices, showed signi?cant improvement in performance of Cardiorespiratory endurance but the mean gain achieved by combined exercise and yogic practices groups was higher than the other groups.
ABSTRACT
Background: Cardiorespiratory endurance is the most important component of health fitness concerned with the aerobic efficiency of the body. The VO2 max (maximum oxygen uptake) is the criterion measure of cardiorespiratory fitness that determines amount of oxygen consumed per kilogram of body weight per minute of exercise. Aim and Objectives: The aim and objective of the study is (1). To assess the heart rate and VO2 max among Indian wrestlers and age and sex-matched healthy controls and (2). To find the correlation between resting heart rate and VO2 max (if any). Materials and Methods: About 35 wrestlers aged between 18 and 25 years practicing in district stadium Belgaum and 35 age and sex-matched students of KLE University, Belgaum were enrolled as controls. Resting heart rate was measured, and cardiorespiratory endurance test was done on treadmill to calculate the VO2 max using Bruce protocol. Results: The data were analyzed using Student unpaired “t-test” (P < 0.05 was considered as significant). Karl Pearson’s correlation coefficient was used to evaluate strength of association between heart rate and VO2 max. The mean resting heart rate of players was significantly less than that of the controls (P < 0.001). Mean VO2 max was significantly higher in wrestlers than in the controls (P < 0.001). Negative correlation was found between the resting heart rate and VO2 max among the wrestler’s and controls. Conclusion: The higher VO2 max in the wrestlers can be attributed to the duration of training which causes greater increase in cardiac output and arteriovenous O2 difference. Resting heart rate of the wrestlers was found to be lower than that of the sedentary people. High VO2 max and low resting heart rate are both associated with cardiovascular fitness and common among endurance players. These could be beneficial tools for trained wrestlers looking to improve their performance.
ABSTRACT
BACKGROUND: Maximal oxygen uptake (VO2 max) is the most direct, effective and objective index for determining cardiorespiratory endurance and exercise capacity, but there are few studies on the varying data of VO2max in rats for a long time. In addition, the effect of high-intensity interval training on the cardiorespiratory endurance in rats during age increasing has not yet been reported. OBJECTIVE: To investigate the improvement of 16-week high-intensity interval training on the cardiorespiratory endurance in rats, and to continuously measure the VO2 max for 16 weeks in 29-week-old rats, so as to provide data reference for the precise control of training intensity. METHODS: Twenty-eight male Wistar rats aged 29 weeks old were randomly assigned into a quiet control group (normal feeding, no training) and a high-intensity interval training group. The latter group underwent the interval exercise of high-intensity (90% VO2 max) and low-intensity (50% VO2 max), 5 times per week, for 16 weeks. The VO2 max and corresponding maximal running velocity were tested and compared every 2 weeks. The study was approved by the Ethics Committee of Sports Science and Physical Health Education Department, Beijing Sport University, with the approval No. 2015025. RESULTS AND CONCLUSION: (1) With the increasing age from 29 to 45 weeks, the VO2max fluctuated down-up-down. After 16 weeks of exercise, the VO2max was decreased by 31.6% in the high-intensity interval training group and 47.9% in the quiet control group. The VO2 max in the high-intensity interval training group was significantly higher than that in the quiet control group (P < 0.01). (2) The decrease of VO2 max in the high-intensity interval training group was significantly lower than that in the quiet control group at 6,8, and 16 weeks (P < 0.05 or P < 0.01). (3) The increase of maximal running velocity in the high-intensity interval training group was significantly higher than that in the quiet control group at 4 and 8 weeks (P < 0.05 or P < 0.01). (4) The maximal running velocity was positively correlated with VO2 max in rats. (5) These results suggest that age increasing is an irreversible factor, and high-intensity interval training can alleviate the decrease of cardiorespiratory endurance. Six-week high-intensity interval training can significantly improve the decrease of cardiorespiratory endurance in rats due to age increasing. Eight-week high-intensity interval training can significantly delay the decrease of cardiorespiratory endurance in rats due to age increasing. Four-week high-intensity interval training can promote the value of maximal running velocity and improve sports ability.
ABSTRACT
Abstract Objective: Evaluate the relationship between body mass index and physical fitness in a cross-sectional sample of Brazilian youth. Methods: Participants were 3849 adolescents (2027 girls) aged 10 -17 years. Weight and height were measured; body mass index was calculated. Physical fitness was evaluated with a multistage 20 m shuttle run (cardiovascular endurance), standing long jump (power), and push-ups (upper body strength). Participants were grouped by sex into four age groups: 10 -11, 12 -13, 14 -15, and 16 -17 years. Sex-specific ANOVA was used to evaluate differences in each physical fitness item among weight status categories by age group. Relationships between body mass index and each physical fitness item were evaluated with quadratic regression models by age group within each sex. Results: The physical fitness of thin and normal youth was, with few exceptions, significantly better than the physical fitness of overweight and obese youth in each age group by sex. On the other hand, physical fitness performances did not consistently differ, on average, between thin and normal weight and between overweight and obese youths. Results of the quadratic regressions indicated a curvilinear (parabolic) relationship between body mass index and each physical fitness item in most age groups. Better performances were attained by adolescents in the mid-range of the body mass index distribution, while performances of youth at the low and high ends of the body mass index distribution were lower. Conclusion: Relationships between the body mass index and physical fitness were generally nonlinear (parabolic) in youth 10 -17 years.
Resumo Objetivo: Avaliar a relação entre o índice de massa corporal e a aptidão física em uma amostra transversal de jovens brasileiros. Métodos: Os participantes foram 3.849 adolescentes (2.027 meninas) entre 10-17 anos. Foram medidos o peso e a estatura e foi calculado o índice de massa corporal. A aptidão física foi avaliada com: a corrida vaivém de 20 metros de vários estágios (resistência cardiovascular), impulsão horizontal (energia) e flexões (força superior do corpo). Os participantes foram agrupados por sexo em quatro faixas etárias: 10-11, 12-13, 14-15 e 16-17 anos. A Anova específica para sexo foi usada para avaliar as diferenças em cada item de aptidão física entre as categorias de status do peso por faixa etária. As relações entre o índice de massa corporal e cada item de aptidão física foram avaliadas com os modelos de regressão quadrática por faixa etária com relação ao sexo. Resultados: A aptidão física de jovens magros e normais foi, com poucas exceções, significativamente melhor do que a aptidão física de jovens com sobrepeso e obesos em cada faixa etária por sexo. Por outro lado, os desempenhos na aptidão física não diferiram de forma consistente, em média, entre jovens magros e com peso normal e entre jovens com sobrepeso e obesos. Os resultados das regressões quadráticas indicaram uma relação curvilínea (parabólica) entre o índice de massa corporal e cada item de aptidão física na maior parte das faixas etárias. Os melhores desempenhos foram obtidos pelos adolescentes na faixa intermediária da distribuição do índice de massa corporal, ao passo que os desempenhos dos jovens nas extremidades inferiores e superiores da distribuição do índice de massa corporal foram menores. Conclusão: As relações entre o índice de massa corporal e a aptidão física foram, em geral, não lineares (parabólica) nos jovens entre 10-17 anos.
Subject(s)
Humans , Male , Female , Child , Adolescent , Thinness/physiopathology , Body Mass Index , Physical Fitness/physiology , Pediatric Obesity/physiopathology , Cardiorespiratory Fitness/physiology , Brazil , Cross-Sectional StudiesABSTRACT
Background: Cycling is an endurance sport relying mainly on aerobic capacity to provide fuel during long-duration cycling events. Athletes are constantly searching for new methods to improve this capacity through various nutritional and ergogenic aids. Purpose: The aim of the study was to find out the effect of Ashwagandha on the cardiorespiratory endurance capacity, that is, aerobic capacity of elite Indian cyclists. Materials and Methods: Forty elite (elite here refers to the participation of the athlete in at least state-level events) Indian cyclists were chosen randomly and were equally divided into experimental and placebo groups. The experimental group received 500 mg capsules of aqueous roots of Ashwagandha twice daily for eight weeks, whereas the placebo group received starch capsules. Outcome Measures: The baseline treadmill test for the cyclists were performed to measure their aerobic capacity in terms of maximal aerobic capacity (VO2 max), metabolic equivalent, respiratory exchange ratio (RER), and total time for the athlete to reach his exhaustion stage. After eight weeks of supplementation, the treadmill test was again performed and results were obtained. Results: There was significant improvement in the experimental group in all parameters, whereas the placebo group did not show any change with respect to their baseline parameters. There was significant improvement in the experimental group in all parameters, namely, VO2 max (t = 5.356; P < 0.001), METS (t = 4.483; P < 0.001), and time for exhaustion on treadmill (t = 4.813; P < 0.001) in comparison to the placebo group which did not show any change with respect to their baseline parameters. Conclusion: Ashwagandha improved the cardiorespiratory endurance of the elite athletes.
ABSTRACT
The purpose of this study was to clarify the validity of 12-min submaximal treadmill walk (TMW) and run (TMR) tests, as indirect measures of cardiorespiratory endurance, and to develop estimation equations of cardiorespiratory endurance using TMW or TMR performance and some other useful items correlating with cardiorespiratory endurance. Fifty-one young adult men, aged 20 -r34 years (22.8±3.6), walked or ran for 12 minutes on the treadmill at the intensity corresponding to the level 13 on the Borg's ratings of perceived exertion (RPE 13), and performed a maximal incremental exercise test. Mean (± SD) of oxygen uptake corresponding to anaerobic threshold (VO<SUB>2</SUB>AT) and maximal oxygen uptake (VO<SUB>2</SUB>max) were 42.0 ± 9.0 ml/kg/min and 55.9 ± 7.4 ml/kg/min, respectively, and mean (± SD) of 12-min walk and run distances were 1221 ± 103 m and 2108 ± 269 m, respectively. Cardiorespiratory endurance indices (VO<SUB>2AT</SUB> and VO<SUB>2</SUB>max) significantly correlated with TMW (r=0.49 and 0.48, respectively) and with TMR (r=0.69 and 0.68, respectively) . A stepwise multiple regression analysis was applied to determine the estimation equations of the cardiorespiratory endurance using VO<SUB>2AT</SUB> or VO<SUB>2</SUB>max as a dependent variable, and TMW or TMR distance, age, resting heart rate (HRrest), and exercise frequency in a week as independent variables. The multiple regression equations of VO<SUB>2AT</SUB> and VO<SUB>2</SUB>max were developed as follows : When TMW distance entered as an independent variable, VO<SUB>2AT</SUB> = 20.781 X<SUB>1</SUB> + 2.298 X<SUB>3</SUB> - 0.29 X<SUB>4</SUB> + 31.855 (r = 0.83, SEE = 5.33 ml/kg/min) : VO<SUB>2</SUB>max =19.941 X<SUB>1</SUB> + 1.127 X<SUB>3</SUB> - 0.208 X<SUB>4</SUB> - 0.656 X<SUB>5</SUB> - 0.853 X<SUB>6</SUB> + 77.884 (r = 0.88, SEE = 3.96 ml/kg/min), and when TMR distance entered as an independent variable, VO<SUB>2</SUB>AT =15.443 X<SUB>2</SUB> + 2.158 X<SUB>3</SUB>- 0.157 X<SUB>4</SUB> + 14.234 (r = 0.90, SEE = 4.18 ml/kg/min) ; VO<SUB>2</SUB>max =10.817 X<SUB>2</SUB> + 1.274 X<SUB>3</SUB> - 0.1946 X4 - 0.504 X<SUB>5</SUB> + 55.234 (r = 0.89, SEE = 3.79 ml/kg/min), where X<SUB>1</SUB> : TMW distance (m), X<SUB>2</SUB>: TMR distance (m), X<SUB>3</SUB> : exercise frequency in a week (d/wk), X<SUB>4</SUB>: HRrest (b/min), X<SUB>5</SUB>: age (yr) and X<SUB>6</SUB>: BMI. It is concluded that cardiorespiratory endurance could be better estimated by a combination of submaximal exercise performance and some easily measurable items correlating with cardiorespiratory endurance such as exercise frequency, circulatory function, chronological age and body composition.