The Effects of Pre-Race Apnoeas on 400-m Freestyle Swimming Performance

This study aimed to establish whether a series of three apnoeas prior to a 400-m freestyle time-trial affected swimming performance when compared to, and combined with a warm-up. Nine (6 males, 3 females) regional to national standard swimmers completed four 400-m freestyle time-trials in 4 randomized conditions: without warm-up or apnoeas (CON), warm-up only (WU), apnoeas only (AP) and warm-up and apnoeas (WUAP). Time-trial performance was significantly improved after WUAP (275.79 ±12.88 s) compared to CON (278.66 ±13.31 s, P = 0.035) and AP (278.64 ±4.10 s, P =0.015). However, there were no significant differences between the WU (276.01 ±13.52 s, P >0.05), and other interventions. Spleen volume compared to baseline was significantly reduced following the apnoeas by a maximum of ~45% in the WUAP and by ~20% in WU. This study showed that the combination of a warm-up with apnoeas could significantly improve 400-m freestyle swim performance compared to a control and apnoea intervention. Further investigation into whether long-term apnoea training can enhance this response is justified.