After an extended winter and pleasant spring season, summer is here with a vengeance. Higher temperatures and oppressive humidity have settled in with no signs of leaving anytime soon. Performing a chore as simple as bringing in groceries from your car often leaves one a hot, sweaty mess. More strenuous exercise means profuse sweating which, if not accounted for, could be dangerous. Does this mean we should forgo training until cooler temperatures return? Of course not, if that were the case, we'd be hard pressed to find favorable conditions until well into October. No, it simply means we have to understand the changing environment and adjust accordingly.
The combination of heat and humidity has a direct impact on athletic performance. As the temperatures rise, our bodies have to work harder to regulate their internal temperatures. This is evidenced by an increased sweat rate which, if unaccounted for, can lead to dehydration. As the body becomes more and more dehydrated, our blood thickens and our heart has to work harder by increasing the heart rate to circulate blood and deliver oxygen throughout our systems.
Athletes that train based on heart rate or pace are all too familiar with an increased heart rate. Training at a specified heart rate often means having to go much slower in hot/humid conditions than one would in a more comfortable environment. At a given perceived exertion level, heart rate will be higher and pace will be slower solely due to the increased temperatures. I often hear my athletes complain about not being able to run as fast or that the workouts seem harder or that they feel "out of shape" during these peak summer months because the numbers they are reporting don't match up to the efforts they feel they are putting out. They are exactly correct. They don't match up but it's not because they are woefully underperforming, it's that they are working harder to combat an environment they have little control over.
What can you do to help offset this issue? First and foremost, hydrate properly. I can't stress enough how important it is to be properly hydrated. We say it often, but it's worth repeating. Drink plenty of water early and often. This means, you should increase your water intake not only during exercise, but throughout the day as well. If you begin a workout in a dehydrated stated, attempting to down a ton of water during the training session is not only futile, but could be dangerous. Keep a bottle of water handy and sip from it regularly.
Wearing proper clothing and training in the early morning hours (before the sun rises) can also help combat the heat and make training more tolerable. It's also important to adjust your expectations and listen to your body. While we want to perform at our best, it is counter-productive to train in conditions that do more harm to your fitness than good. Take longer recoveries, slow down the pace and instead focus on effort rather than results. By putting in the right effort, your results will take care of themselves once the cooler temperatures return. It's possible to beat the heat; you just have to adjust accordingly.