The effect of maximal exertion on the levels of plasma peptides in cyclists with different physical working capacities

Abstract. The studies were carried out on thirty-one sportsmen, cyclists aged 21–28 years, after the termination of a training course just before the start of their season. They exercised on a bicycle ergometer according to the following schedule: 30 N at 60 rev/min for 6 min, 40 N at 70 rev/min for 5 min, 50 N at 80 rev/min for 5 min and 50 N at 90 rev/min until exhaustion. According to the level of training the subjects were divided into three groups. In the three groups of cyclists were determined the concentrations of total plasma peptides and their individual fractions obtained by gel-filtration on Sephadex G-10.
It was found that the total plasma peptide concentration varied with the level of fitness. The lowest plasma peptide concentration was observed in cyclists with the lowest level of fitness and it differed from those observed in cyclists with intermediary and high levels of fitness. After exercise the biggest increase in plasma peptide concentration was found in the cyclists with the low level of fitness, and the lowest one in those with the high level of fitness.
Individual plasma peptide fractions also revealed differences before and after exercise depending on the level of fitness.