External muscle heating during warm-up does not provide added performance benefit above external heating in the recovery period alone

Purpose Having previously shown the use of passive external heating between warm-up completion and sprint cycling to have had a positive effect on muscle temperature (T-m) and maximal sprint performance, we sought to determine whether adding passive heating during active warm up was of further benefit. Methods Ten trained male cyclists completed a standardised 15 min sprint based warm-up on a cycle ergometer, followed by 30 min passive recovery before completing a 30 s maximal sprint test. Warm up was completed either with or without additional external passive heating. During recovery, external passive leg heating was used in both standard warm-up (CONHOT) and heated warm-up (HOTHOT) conditions, for control, a standard tracksuit was worn (CON). Results T-m declined exponentially during CON, CONHOT and HOTHOT reduced the exponential decline during recovery. Peak (11.1 %, 1561 +/- 258 W and 1542 +/- 223 W), relative (10.6 % 21.0 +/- 2.2 W kg(-1) and 20.9 +/- 1.8 W kg(-1)) and mean (4.1 %, 734 +/- 126 Wand 729 +/- 125 W) power were all improved with CONHOT and HOTHOT, respectively compared to CON (1,397 +/- 239 W; 18.9 +/- 3.0 W kg(-1) and 701 +/- 109 W). There was no additional benefit of HOTHOT on T-m or sprint performance compared to CONHOT. Conclusion External heating during an active warm up does not provide additional physiological or performance benefit. As noted previously, external heating is capable of reducing the rate of decline in T-m after an active warm-up, improving subsequent sprint cycling performance.