During an international chess championship tournament in Munich, 14 participants were thoroughly investigated physically in order to find out generally the psychological maximum stress and the autonomic excitability as well as the circulatory conditions during the individual games and to study the metabolic load during the 18 day tournament. Eight of the eleven players who participated in the blood determinations showed at least once during the competition marginal to increased cholesterol levels. In their general physical capacity, their autonomic excitability and their circulatory parameters during the competition the chess players were completely comparable to other sportsmen of the "light athletics" class, so that chess can also rightly be called a class of sport according to these criteria.