It seems a hot bath isn’t just for relaxing, according to an acclimation study by Professor Neil Walsh of Liverpool John Moores University.
The UK team had a group of male athletes undergo a six-day training intervention whereby they ran for 40mins at 65% of their VO2max in ‘temperate conditions’ of 18°C followed by either a hot bath at 40°C or a ‘thermoneutral’ bath at 34°C.
Before and after the six-day period the subjects followed that same 40min protocol with a 5km treadmill time-trial (TT) in conditions of 18°C and 33°C.
The results? Hot-water immersion improved TT performance in the heat but not when running at 18°C. It seems that the daily hot baths acclimatised the runners to hotter climes, indicated not only by performance but also via a more efficient sweat response and lower rectal temperature (a sign that the core’s adapting to the heat).
If you’re racing in hotter temps and wish to give the bathing strategy a go, the subjects enjoyed a 20min bath on day one building to 40mins by day six, though the author suggests 40mins isn’t always required.
Top image credit: Dan Seex