Growth and physical training with reference to heredity

Area of Science:

• Exercise Physiology
• Pediatric Sports Science
• Adolescent Development

Background:

• The impact of endurance training on physiological adaptations in adolescents is not fully understood.
• Previous hypotheses suggested maximal gains from exercise during peak growth periods.

Purpose of the Study:

• To investigate the influence of age on physiological adaptations to endurance training in adolescent males.
• To compare the effects of a 10-week endurance training program on aerobic and cardiorespiratory responses across different adolescent age groups.

Main Methods:

• A 10-week strenuous endurance training intervention was conducted on one twin from twelve identical male twin pairs.
• Twin pairs were aged 10, 13, and 16 years, with one twin training and the other serving as a control.
• Intrapair comparisons assessed changes in VO2max, O2 pulse, blood lactate, ventilation, respiratory rate, and maximal heart rate during maximal bicycle ergometry.

Main Results:

• Ten-year-old trained twins showed greater VO2max improvements than their untrained counterparts.
• Sixteen-year-old trained twins exhibited enhanced VO2max, O2 pulse, blood lactate, ventilation, and respiratory rate, alongside decreased maximal heart rates compared to controls.
• Thirteen-year-old twins demonstrated similar changes between trained and untrained individuals.
• Both 10- and 16-year-old groups showed superior VO2max gains compared to the 13-year-old group.

Conclusions:

• Age significantly modulates the physiological benefits of endurance training in adolescent males.
• The hypothesis that exercise interventions yield greater benefits during the peak growth spurt (around age 13) is not supported by these findings.
• Training adaptations in VO2max are more pronounced in younger (10 yr) and older (16 yr) adolescents compared to mid-adolescence (13 yr).