Effect of in- versus out-of-water recovery on repeated swimming sprint performance

The aim of this study was to compare the effect of passive in- (IN) versus out-of-(OUT) water recovery on performance during repeated maximal sprint swimming. Nine well-trained male swimmers (21 +/- 3.5 years) performed six repeated maximal 50-m sprints (RS), departing every 2 min, interspersed with either IN or OUT recovery. Best (RS(b)) and mean (RS(m)) RS times, percentage speed decrement (%Dec) and between-sprint heart rate recovery (HRR(80s)) were calculated for both conditions. Blood lactate was measured after the third ([La](b) S3) and sixth sprints (post [La](b)). Rating of perceived recovery level (REC) and exertion (RPE) were collected before and after each sprint. Repeated sprint performance was significantly lower in the OUT condition (i.e., for RS(m), P = 0.02, +1.3%, 90% CI -0.7, 3.2%). OUT was also associated with poorer HRR(80s) (P < 0.001, -23%, 90% CI -34, -10%) and higher [La](b) S3 (P < 0.01, +13%, 90% CI -1, 29%). Post [La](b), however, was similar (P = 0.44, +1%, 90% CI -7, 10%). RPE and REC were not significantly different between the two conditions (all P > 0.43). To conclude, present results confirm the beneficial effect of the IN condition on repeated swim sprint performance, but also suggest that the OUT recovery modality could be an effective training practice for eliciting a low intramuscular energy status.