ABSTRACT
PURPOSE: The presence of a maturational threshold that modulates children's physiological responses to exercise training continues to be debated, not least due to a lack of longitudinal evidence to address this question. The purpose of this study was to investigate the interaction between swim-training status and maturity in nineteen trained (T, 10 ± 1 years, -2.4 ± 1.9 years pre-peak height velocity, 8 boys) and fifteen untrained (UT, 10 ± 1 years, -2.3 ± 0.9 years pre-peak height velocity, 5 boys) children, at three annual measurements. METHODS: In addition to pulmonary gas exchange measurements, stroke volume (SV) and cardiac output ([Formula: see text]) were estimated by thoracic bioelectrical impedance during incremental ramp exercise. RESULTS: At baseline and both subsequent measurement points, trained children had significantly (P < 0.05) higher peak oxygen uptake (year 1 T 1.75 ± 0.34 vs. UT 1.49 ± 0.22; year 2 T 2.01 ± 0.31 vs. UT 1.65 ± 0.08; year 3 T 2.07 ± 0.30 vs. UT 1.77 ± 0.16 l min(-1)) and [Formula: see text] (year 1 T 15.0 ± 2.9 vs. UT 13.2 ± 2.2; year 2 T 16.1 ± 2.8 vs. UT 13.8 ± 2.9; year 3 T 19.3 ± 4.4 vs. UT 16.0 ± 2.7 l min(-1)). Furthermore, the SV response pattern differed significantly with training status, demonstrating the conventional plateau in UT but a progressive increase in T. Multilevel modelling revealed that none of the measured pulmonary or cardiovascular parameters interacted with maturational status, and the magnitude of the difference between T and UT was similar, irrespective of maturational status. CONCLUSION: The results of this novel longitudinal study challenge the notion that differences in training status in young people are only evident once a maturational threshold has been exceeded.
Subject(s)
Cardiac Output , Exercise/physiology , Puberty/physiology , Pulmonary Gas Exchange , Adolescent , Case-Control Studies , Child , Female , Humans , Longitudinal Studies , MaleABSTRACT
UNLABELLED: The aim of this study was to investigate the effects of exercise training on the peak oxygen uptake (peak VO2) and blood lipid profile of 13 to 14-y-old postmenarcheal girls. Treadmill determined peak VO2, total cholesterol, high density lipoprotein cholesterol, low density cholesterol, and triglycerides were the outcome measures assessed at baseline and following exercise training. Twenty girls completed a 20-wk programme of exercise training which involved maintaining the heart rate at 75-85% maximum for 20 min, three times per week. Heart rate was rigorously monitored using telemetry throughout each training session. Eighteen girls acted as the control group. There were no significant (p > 0.05) changes in the outcome measures following the training programme. CONCLUSIONS: These findings suggest that exercise training of this frequency, intensity and duration for a period of 20 wk has no significant effect on either the peak VO2 or blood lipid and lipoprotein profile of normolipidaemic, postmenarcheal girls.
Subject(s)
Exercise/physiology , Lipids/blood , Oxygen Consumption , Physical Education and Training , Adolescent , Age Factors , Analysis of Variance , Body Height , Cholesterol/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Female , Heart Rate/physiology , Humans , Regression Analysis , Sex Factors , Skinfold Thickness , Time Factors , Triglycerides/bloodABSTRACT
Although the intensity of training in an exercise program is important, social environment and selection of activities are the factors that enhance patient compliance. Motivation of patients may be the single most important factor in a cardiac rehabilitation program. Such a program must recognize individual needs, set goals, permit opportunities for choice, provide feedback, and have a functioning reward system.