Summer is Coming!

By Lisbeth Hoyt PT, DPT, CSCS

As the weather starts getting warmer, those of us who haven't been braving the cold outdoor temperatures start to move our runs outside. Ideally, we’d have some acclimatization time as the temperatures slowly rise, but as the Boston Marathon runners just encountered, sometimes an unexpected humid and sunny day occurs, and it may be race day.

One of the biggest challenges with running in heat is the increase in external body temperature and dehydration; both which can negatively affect your performance. It typically takes about two weeks of running in warmer temperatures for your body to adjust to the rise in core temperature. Our bodies cool themselves as sweat evaporates off the body. In warmer weather, your body diverts more blood to the skin to cause sweating, which results in less blood to your working muscles, causing a slight drop in performance, which is why we feel slower in the summer.

If the forecast is starting to look a little toasty for your upcoming race (or tropical vacation), you can still prepare your body to perform in warmer temperatures. Start by drinking more water and electrolyte beverages for the two weeks leading up to race day. If you aren't arriving until race weekend, it will be more challenging for your body to acclimate to the environment. Having adequate hydration and electrolytes in your system will help you to be as prepared as possible.

Additionally, try making a slushy (with water, nuun or Gatorade) the night before to drink at the start line. A study found that drinking an ice slushy prior to a treadmill run to exhaustion test (VO2max) in a hot environment, lowered body temperatures, heart rate, and sweating rate as well as the rating of perceived exertion. Drinking something icy at the start is an effective pre-cooling method if you find yourself about to race in a hot environment.

And while we may not miss winter yet, as the temperatures start to rise make sure your body is ready to perform in the heat and humidity that all New Yorkers will soon be complaining about. Stay cool out there!

Feldman, D. (2011). Ice Slurry Ingestion Increases Core Temperature Capacity and Running Time in the Heat. Yearbook of Sports Medicine,2011, 311-312. doi:10.1016/j.yspm.2011.04.002