If I had a dollar for every client who mentioned the heat to me this week…and rightfully so! We have been blasted with a heat wave and still want and need to run. However, it’s important to understand the effects heat has on our training and how to adapt for the heat in order to do it safely.
The ideal temperature for training, according to research, is 11.67C (53F). Above or below this temperature, technically, requires an adjustment in pace expectations. For the purpose of relevance, we are only going touch on the effects of heat on pace today.
When we get hot and our skin turns red, the physiological response happening here is an increase in blood being directed to the skin to assist in cooling us down. In order for this to happen, our blood-flow is moving away from the muscles, thereby decreasing the oxygen to them. This explains the heavy legs, increased heart rate, increase in perceived effort to hold a pace, and likely an overall decrease in performance. In order to decrease the effects of heat, one suggestion is to cool your core temperature down as much as possible before heading out for your run. Ingesting cold fluids or sitting with an ice pack before heading out are a few options. Be sure to wear a hat and sunscreen to reduce the exposure and absorption of the sun’s UV rays, and make sure you have water with you. Lastly, don’t run in the hottest part of the day, if you can avoid it. Another suggestion is to adjust your expected training paces. There are calculators available online, such as Runners Connect, that help you determine the pace you should be running based on changes in temperature in variation to your regular aerobic pace. Or you can just listen to your Central Governor system: if it's telling you to slow down, slow down!