Recent research found that drinking a super chilled beverage actually inhibits your natural sweating and thermoregulatory response which would backfire and lead to a very uncomfortable ride or run.
Alternatively, having a warm or hot beverage was found to better prepare the body for the rigours of outdoor exercise by preeminently increasing one’s sweat rate.
Researchers from the University of Sydney found that drinking a super-chilled beverage such as a slushie triggered temperature sensors in the stomach, which trick the body into thinking it’s much colder than it really is and has unintended effects such as a reduced sweat rate. This is bad news before heading out for a hot ride or run since you could end up heating up more than you should due to less efficient cooling.
And by the same, somewhat ironic, logic, drinking a hot beverage before your workout could actually help you by signaling to the body that it’s about to heat up and increase its sweat rate to better cool you down, even before you start to heat up.
Closely related is the idea of pre-cooling before a workout. Pre-cooling would include having a cold shower, an ice bath, wearing a cooling vest, wet cap or just applying something cold to your body before you exercise.
The research is far from clear but the current consensus seems to be that if the cooling is simply external–think putting an ice pack on your head or neck–and if your core temperature doesn’t change, you shouldn’t expect much, if any, of a positive physiological benefit. That said, the psychological benefit of “feeling” cooler and the physical sensation of cooling down can and does definitely have benefits to our perceived level of comfort/discomfort so could indeed help you feel better in the early kilometres of a workout.
Rehydrating by replacing lost fluids and electrolytes following any hot workout is still considered good and essential practice. Taking a post-ride or run ice bath or cold shower will certainly feel “good” for achy muscles and joints but the science is again inconclusive regarding it’s effectiveness at promoting recovery.