We investigated whether physical fitness and body composition in 8-10-year-old Danish children are associated with sports club participation. The study included 423 schoolchildren, comprising 209 girls and 214 boys, of whom 67 and 74%, respectively, were active in sports clubs. Yo-Yo Intermittent Recovery level 1 for Children (YYIR1C), balance, jump and coordination tests, together with DXA scans, were used to determine exercise capacity and body composition. Children active in sports clubs had better (P<0.05) YYIR1C (33%, 767±26 vs. 575±29 m), 20-m sprint (3%, 4.33±0.03 vs. 4.48±0.04 s), coordination (6%, 68±1 vs. 72±1 s) and balance test performances (9%, 19.3±0.5 vs. 21.2±0.7 falls/min) and lower fat mass index (16%, 3.8±0.1 vs. 4.5±0.2 kg(fat)·m) than children not active in sports clubs. Ball game players had better (P<0.05) YYIR1C (38%, 925±39 vs. 671±28 m), 20-m sprint (4%, 4.25±0.03 vs. 4.42±0.04 s) and coordination test performances (5%, 65±1 vs. 69±1 s), along with higher (P<0.05) lean body mass (5%, 24.00±0.22 vs. 22.83±0.25 kg) and whole-body BMD (2%, 0.90±0.00 vs. 0.88±0.00 g/cm) compared to children active in other sports. The study showed that 8-10-year-old Danish children engaged in sports club activity, especially ball game players, have better exercise capacity and superior body composition compared to children not active in sports clubs.