Aerobic performance capacity in athletes

Abstract

Aerobic performance capacity of 84 male and 5 female Finnish athletes practising 11 different sport events as well as 31 reference subjects was studied. The main parameters of aerobic performance capacity were maximal oxygen uptake (maxVo₂) in leg and arm work, succinate dehydrogenase activity (SDH) and percentage of slow twitch fibers (%ST fibers) in m. vastus lateralis (VL), m. gastrocnemius c.l. (GL) and m. deltoideus (D). The speed skaters (5.58 1 x min⁻¹), male cross-country skiers (5.42 1 x min⁻¹), canoeists (5.25 1 x min⁻¹) and long-distance runners (5.19 l x min⁻¹) had highest maxVo₂ in leg work. In ml x kg⁻¹ x min⁻¹ the male cross-country skiers, long-distance runners, speed skaters and Nordic combination skiers had highest mean values (72.8 - 78.3 ml x kg⁻¹ x min⁻¹). In arm work the canoeists had the highest mean value of 4.56 1 x min⁻¹. The oxidative capacity of the muscles as judged on the basis of %ST fibers and SDH activity was highest in the long-distance runners. Maximal oxygen uptake correlated positively with %ST fibers (r = .56. p<.001) and SDH activity (r = .38, p<.001) in m. VL. The SDH activity and %ST fibers in m. VL correlated a1so with one another ( r = .39, p<.001). It was concluded that the oxidative capacity of the muscles is not the limiting factor for maximal oxygen uptake. The role of the oxidative capacity of the muscles might be important during submaximal work of long duration and when a relatively small muscle mass is activated (long-distance running). MaxVo₂ might be the most important determinant of physical performance when large muscle mass is activated during maximal work of a duration from several minutes up to one hour (cross-country skiing).