As summer running and racing is creeping in, most of the country is beginning to deal with warmer temps and more humid conditions. This has a tangible effect on running performance and race results.
In Alex Hutchinson's book Endure, he talks a lot about heat's role on limiting performance. Ultimately, it's your body's way of protecting itself against heatstroke. It seems for most people there is an internal threshold at about 104 degrees Fahrenheit where once your core temperature exceeds that limit it begins to more or less shut down and performance suffers.
So how can one limit the effects heat has in running well? For starters, your body does acclimate to running in warmer temperatures. According to Hutchinson, stressing your body through exercise in the heat for about two weeks causes significant physiological benefits that help you deal better with warmer temperatures. In many causes, however, the dew point has a more significant affect on performance that just temperature itself. The higher the dew point, the less sweat is able to evaporate from your skin which reduces the cooling effect sweating serves.
Hutchinson writes extensively about the positive impacts "precooling" can have on performance. Precooling is essentially the act of trying to lower your core temperature before strenuous activity in heat. He cites various examples of how having a lower core temperature prior to activity results in being able to push harder for longer compared to starting at an elevated core temperature. Trent Stellingwerff has also cited numerous studies about precooling and performance as well.
Hutchinson mentions the Australian Olympic Team's approach to precooling where in 2008 they shipped seven slushie machines to Beijing and had them available for their athletes competing in hot conditions. According to Hutchinson, Australian scientists hypothesized that consuming slushie drinks sweetened similarly to sports drinks could lower core temperatures by one degree and boost endurance in the heat. He goes on to explain that another benefit of these slushie drinks is that not only do they lower core temps before exercise, but they also allow athletes to get to a higher core temperature during exercise before exhaustion sets in.
The other piece of the puzzle that Hutchinson includes is the mental side of dealing with the heat. He mentions a study where cyclists were able to improve performance in heat simply by shifting their language from using such phrases as "It's so hot in here" and "I'm boiling" to more positive phrases like "Keep pushing, you're doing well." The group with the positive self-talk were able to last 11 minutes during an endurance test versus 8 minutes in the other group, and as a result "pushed their core temperature at exhaustion more than half a degree higher."
So in summary, what can one do to try to run better in the heat? Here are some of my takeaways:
Do your best to keep your core temperature low before race or workout situations. Hold frozen water bottles in your hands or have towels sitting in iced water to keep around your neck and face.
Consider shortening your warm-up a bit as your core temperature will rise as the time you spent moving increases.
Don't psych yourself out. You're not going to be able to run as well in heat as you would in cooler temperatures, but that doesn't mean you cannot run very well. Use positive self talk and don't defeat yourself before an effort even begins.
Don't be a slave to numbers on your watch. Heat humbles everyone and at different rates. Trust your ability to run by feel knowing at the end of the day your result would be even better in ideal conditions.
