Expert opinion: Dr Steve Faulkner is an exercise physiologist at Loughborough University with a special interest in the factors that limit exercise performance
You’re out on a long group ride on a warm day; midway through, everyone inevitably stops for a cafe break. Your friends all order cold drinks, which they assume are best for cooling them down. But are they right? Might you be better off with a hot tea or coffee with your slice of cake?
It turns out that the old belief that having a hot drink on a warm day is the better option for keeping cool, may not be far from the truth.
Having a warm drink triggers the body’s mechanisms responsible for maintaining a stable body temperature, principally sweating.
This thermoregulatory (cooling) effect may outweigh the ‘thermal load’ (warming) brought on directly by the hot drink. A very cold drink, on the other hand, may actually reduce sweating.
In 2012, Dr Ollie Jay published a study investigating whether drinking a warm drink could lower the amount of heat stored by the body compared to ingesting a cold drink.
In this study volunteers cycled at a relatively low intensity for 75 minutes at 24°C and 23 per cent humidity, while consuming water at 1.5˚C, 10˚C, 37˚C or 50˚C.
They found that having a warm drink actually resulted in lower body temperatures compared to having a cool or cold drink.
As expected, this seems to be because the warm drink caused an increase in sweating. An increase in sweating allows for greater heat loss as a consequence of more evaporation from the skin.
Make your ride count for more with the right routine
When the same group compared the effects of warm versus icy drinks during exercise, they reported similar findings — heat storage was lower following the warm drink.
However, when humidity is high, sweat evaporation is reduced, so the effect of hot drinks may be lessened. So, if exercising in high heat and humidity, cold drinks should be the better choice.
Body temperature is key to determining an athlete’s performance, particularly in endurance events like cycling.
In warm conditions with low humidity, replacing cold drinks with warm ones may help give you the edge, leaving the peloton trailing in your wake on the ride home!