Training - overtraining: Influence of a defined increase in training volume vs training intensity on performance, catecholamines and some metabolic parameters in experienced middle- and long-distance runners. - Lehmann,M.; Baumgartl,P.; Wiesenack,C.; Seidel,A.; Baumann,H.; Fischer,S.; Spori,U.; Gendrisch,G.; Kaminski,R.; Keul,J. (Eur J Appl Physiol, 1992)