SUTTON, J. R. VO2max–new concepts on an old theme.Med. Sci. Sports Exerc., Vol. 24, No. 1, pp. 26–29, 1992. This symposium VO2max–new concepts on an old theme” is dedicated to the memory of Hermann Rahn, whose inspiration has led many young investigators to explore new horizons. In the debate on factors limiting VO2max at altitude Hermann Rahn stimulated further discussion between those camps supporting the central circulation as limiting VO2max and those proposing a peripheral diffusion limitation.