Cardiorespiratory Characteristics Research Articles

A five-year follow-up study on cardiorespiratory function in adolescent elite endurance runners.

It is not known whether the superior cardiorespiratory function in adolescent athletes is attributed to the effects of training or to genetic disposition. We re-examined 6 elite endurance runners and 7 boys with ordinary physical activity 5-6 years after the first examination. At the age of 14 years the two groups did not differ as regards height, weight, percent body fat and lean body mass (LBM). The runners had slightly superior cardiorespiratory characteristics but, with the exception of lower resting and maximal heart rates (HR) in the runners, the differences were not statistically significant. At the age of 19-20 years the runners had significantly higher maximal oxygen uptake (VO2 max) per kg body weight (74 vs. 61 ml/min/kg), VO2 max/LBM (85 vs. 74 ml/min/kg LBM), calculated work at a heart rate of 170 beats/min (W170) per kg body weight (3.9 vs. 2.7 W/kg), W170/LBM (4.5 vs. 3.3 W/kg LBM), larger relative heart volume (HV) (472 vs. 369 ml/m2) and lower resting HR (52 vs. 68 beats/min) than the controls. The runners also displayed greater increases in the growth-corrected percentage changes in cardiorespiratory variables, but the differences did not reach statistical significance. We conclude that the relative VO2 max, W170 and HV values in the runners had increased as a result of a prolonged endurance training.

Physiological profile of middle-aged male and female tennis players

Cardiorespiratory characteristics, relative body fat, grip strength and selected skinfolds, circumferences and bone diameters were determined in 25 males and 25 females (31--55 yr) whose exclusive mode of regular exercise was tennis (9.7--11.1 hr/wk). Mean resting heart rates were 54 beats/min for the males and 61 beats/min for the females. Mean resting blood pressures were 117/75 and 107/68 mmHg for the males and females, respectively. Compared to normally active populations of the same age and sex, the tennis players displayed an above average maximal oxygen uptake (mean values equal 50.2 ml/kg.min-1 for the males and 44.2 ml/kg.min-1 for the females), below average relative body fat (mean values equal 19.3% and 20.3% for the males and females, respectively), greater dominant grip strengths, and similar non-dominant grip strengths. The results indicate that either physically superior individuals choose to play tennis, or that regular tennis participation produces above average levels of fitness, or both.

Physiological Responses to Endurance Work Performance in Relation to Altitude

A study of work capacity and physiological responses to endurancework performance was carried out at plains (Chandigarh 750 ft. above sea level) and at higher altitude (Sainj, India 4500 ft. above sea level). Investigations were carried out on members of a field party consisting of 8 individuals (4 males and 4 females) in the age group of 20-25 years. The team members were first examined soon after their arrival at Sain j. The second reading was taken after a stay of about 14-15 days in Sainj, and the third reading was taken after about a month of their return to plains.The study revealed that cardio-respiratory characteristics are closely related to altitudinal exposure. The principal adaptive responses to hypoxic conditions at higher altitude consisted of increase in pulse rate and decrease in oral temperature and blood pressure (both systolic and diastolic). Vital capacity did not show any adaptive response to altitude at least up to 4500 ft. above sea level. Increase in physical work capacity was observed at higher altitude. Physiological responses to endurance work performance at plains and at higher elevations revealed marked differences.

Cardiorespiratory characteristics and adaptation to high altitudes.

AbstractThe lowered partial pressure of oxygen at high altitude is one of the severest and most pervasive environmental stresses affecting human populations. Virtually all organ systems and physiological functions are affected by hypoxia, and only elaborate modern technology can temporarily ameliorate the hypoxic stress of altitude exposure. The biological and behavioral responses of newcomers, sojourners, and native residents at higher elevations could provide a paradigm of the study of man's adaptation to the physical environment.Cardiorespiratory characteristics are closely related to altitude exposure, and certain alterations in these characteristics constitute the principal adaptive responses of the organism to hypoxia. However, not all altitude‐related characteristics are beneficial to the organism; some peculiar characteristics occurring at high altitude may be without benefits, or may even be pathological and maladaptive. The roles of age, sex, race, physical condition, nutrition, and intensity and frequency of exposure during growth and development of altitude‐related characteristics are not entirely understood. Moreover the influence of even large circulatory and respiratory alterations, on tissue oxygen tension may be small, and their adaptive significance difficult to evaluate. An equivalent level of functional adaptation might be achieved through differing combinations of structural, functional, and behavioral characteristics. It is concluded that more rigorous evaluations of adaptation to the environment are needed.