Influence of age, sex, body size, smoking, and beta blockade on key gas exchange exercise parameters in an adult population - Gläser, S; Koch, B; Ittermann, T; Schäper, C; Dörr, M; Felix, S B; Volzke, H; Ewert, R; Hansen, J E (Eur J Cardiovasc Prev Rehabil, 2010)