Two studies tested the theory of deliberate practice (Ericsson, Krampe, & Tesch-Romer, 1993) and contrasted results with the sport commitment model (Scanlan, Carpenter, Schmidt, Simons, & Keeler, 1993a, 1993b). In Part I, international, national, and provincial soccer and field hockey players recalled the amount of time they spent in individual and team practice, sport-related activities, and everyday activities at the start of their career and every 3 years since. In Part II, these activities were rated in terms of their relevance for improving performance, effort and concentration required, and enjoyment. A monotonic relationship between accumulated individual plus team practice and skill level was found. In contrast with Ericsson et al.’s (1993) findings for musicians, relevant activities were also enjoyable, while concentration became a separate dimension from effort. The viability of a generalized theory of expertise is discussed.