Training and overtraining markers in selected sport events

Purpose: Varieties of symptoms are supposed to detect overtraining (OT). Be sides the problems of diagnosis and analysis in elite athletes, a daily mon itoring of training status takes place with measurement of the parameters s erum urea (SU) and serum creatine kinase (CK); therefore, their meaningfuln ess will be examined, with special respect inter- and intra-individually. M ethods: Data were obtained from determinations during training from athlete s in rowing and athletes of international level. Results: For 6981 SU deter minations (male, N = 717; female, N = 285), a slightly asymmetric normal di stribution was found (male, 80%, 5-7 mmol.L-1; female, 75%, 4-6 mmol.L-1). Values for women were approximately 1.5 mmol.L-1 lower. Individual variabil ity was enormous: there seems little point in setting fixed value as 8.3 mm ol.L-1 for men and 7.0 mmol.L-1 for women as a critical limit for OT. CK ha s also been measured and evaluated in sports as an essential parameter for determination of muscular stress. Frequency distributions of CK in 2790 sam ples (male, N = 497; female, N = 350) presented an asymmetric normal distri bution with distinct trend toward higher values being evident for the range between 100 and 250 U.L-1. Conspicuously elevated values occurred in the r anges 250-350 U.L-1 and 1000-2000 U.L-1. Men's maximal values were 3000 U.L -1 and 1150 U.L-1 for women. Individual variability was enormous. Athletes with chronically low CK exhibited mainly low variability; those with chroni cally higher values exhibited considerable variability. Conclusions: Establ ishment of both parameters should be useful to determine individual baselin es from a large number of samples. Determinations should be made at least e very 3 d in standardized conditions. If a large increase is observed in com bination with reduced exercise tolerance after a phase of exertion (2-4 d), then the possibility of a catabolic/metabolic activity or insufficient exe rcise tolerance becomes much more likely.