Energy supply for muscle activity in 13- to 14-year-old boys depending on the rate of puberty

The energy supply for muscle activity in healthy boys aged 13–14 years (n = 162) at various puberty stages (PSs) has been studied using functional and ergometric working capacity indices. It has been established that boys at PSs II–IV significantly differ in the indices of power, capacity, and efficiency of bioenergy systems. Three groups of bioenergy indices have been distinguished that differ in the direction of variations in adolescents depending on the rate of puberty. The first group includes the physiological variables the highest levels of which are observed in adolescents with high rates of development. All these indices belong to the anaerobic alactic and anaerobic glycolytic components of physical capability. The second group includes the physiological variables the highest levels of which are observed in adolescents with medium rates of development; the lowest levels, in adolescents with accelerated rates of development. These indices mainly reflect the set of aerobic capacities. The third group includes the physiological variables the highest levels of which are observed in adolescents with low rates of development and the lowest levels, in boys with accelerated rates of maturation. These indices reflect the maximal aerobic power and endurance. It was found that adolescents aged 13–14 years with moderate rates of development are characterized by higher indices of power and capacity of the aerobic energy supply system as compared to adolescents with accelerated maturation. This group of adolescents has also been observed to exhibit a lower maximal aerobic power against a background of higher capacity and efficiency of the aerobic system functioning as compared to adolescents with slow maturation. Adolescents with moderate rates of maturation have been shown to surpass schoolboys with accelerated or slow development with respect to the power of mixed aerobic-anaerobic work. Boys aged 13–14 years with accelerated development have been found to differ from schoolboys with moderate or slow maturation by high anaerobic capacity, relatively low aerobic capacities and an increase in the tone of the parasympathetic nervous system. This should be taken into consideration in terms of a differentiated approach to the formation of load during physical education and athletic training of adolescents aged 13–14 years.