Growing up in the Midwest I was accustomed to harsh winters, and as a runner the weather could be particularly cruel. I still tell stories from my younger, foolish days of running in shorts through the sub-freezing temperatures of central Indiana. I figured it made me tough. And if I’m being honest I still do. Somehow that stupidity feels venerable in retrospect. Regardless, this calloused Indiana boy thoroughly enjoyed his time at Arizona State with it’s balmy desert winters. Just as everyone touts his or her regional pride when living in a new part of the country, I made sure I didn’t lose my Indiana toughness out west. And now I tell the dramatic stories of grueling long runs under the searing summer skies of Arizona. Of course here in the south we are entering the heart of summer, and its time for us to work on our toughness in the stifling heat of the next few months. I am only half joking. There actually is evidence suggesting heat acclimation can have performance benefits in the same way (if not by the same mechanisms) as altitude training, even in cooler weather. Call it toughness, call it increased blood volume and glycogen use efficiency, but heat can be your friend if you take proper preparations this summer.
Hydrate, hydrate, hydrate! Obviously. But there are aspects of hydration that get overlooked and have a big impact on your performances. If you are starting your runs in the morning, which I strongly suggest in the summer, weigh yourself before and after your run to get an idea of how much water weight you are losing. Body weight losses of 2% or more can have dramatic impacts on your performance, and if you aren’t hydrating during the summer you are probably losing 3-4% or more. Finding out how much weight you’re losing helps determine your sweat rate, and an ideal replenishment strategy (replace 1lb of weight loss with 16 ounces of fluid) to stay within that 2% window. If your weight is significantly lower from one morning to the next I would advise taking the day off from running and making sure you focus on rehydrating before you get back to training.
Monitoring Fluid Loss
Checking your morning weight is a good strategy for monitoring hydration, as is aiming for urine with a light yellow hue. Maintaining proper hydration during exercise (and consequently proper temperature regulation, blood plasma levels, and sweat rate) means more than just drinking water. In the Arizona summer I would lose water weight during runs, but my skin and clothing was bone dry at the end of the run. I’m sure many of you have experienced that nice salt encrusted forehead at the end of a hot run. The good news is that doesn’t mean your body is devoid of water, it means you need to take in electrolytes, primarily sodium, as you hydrate in order to replace all that salt stuck on your body.
In addition to flushing out water and sodium on a hot day your body also increases the rate at which it uses muscle glycogen. Caloric replacement is particularly important during longer training sessions (over an hour) and in preparation for longer races such as the half marathon and marathon. Utilizing a sports drink that replaces electrolytes and glucose is ideal for hydrating before and after exercise. I don’t want to get side tracked by post run nutrition (as I’ll assume everyone read my September article on recovery), but its importance is amplified during the heat of the summer when the body is utilizing more glucose and fluid during the run.
I understand the cringe-inducing statement I’m about to make, but utilizing the treadmill is better than putting in a run during the middle of a hot summer afternoon. In extreme heat most people will be unable to replace the 3+ pints of fluid that can be lost per hour of exercise. Additionally, battling those conditions day after day can dramatically decrease performance and prevent recovery day to day. Getting in the air-conditioned gym, while not the shorts-in-sub-freezing-temperature tough guy stupid option, may occasionally be the most prudent choice. Additionally, if your long runs are over 2 hours and you’re struggling late in your runs try starting or finishing the run indoors on a treadmill. Supplementing some running with cross training is also a good way to acclimate to the heat and build your aerobic volume during a base building phase of training.
If you are preparing for summer racing heat acclimation is critical, but minimizing heat exposure on race day will help improve performance. If you typically do a longer warm-up before races consider shortening your routine in warmer temperatures. A 10-12 minute warm-up is plenty for the days where you break a sweat walking out the door in the morning. Taking a cooler with some ice water and towels to the race is even better. Cooling the surface of the skin, particularly the back of the neck and wrists, has shown performance benefits with regard to lowering core temperatures and decreasing the metabolic cost of cooling your body. Chewing on crushed ice has similar effects and lowers your perceived effort in warm conditions. At the USA Track and Field Championships last June we had our ZAP athletes do their entire warm-up around the top of an indoor basketball arena to keep their core temperatures from skyrocketing.
Keep in mind its okay if your workouts and training runs are a little slower. Focus on maintaining your effort in the summer, not your pace; you’ll still reap the same fitness benefits. Otherwise you may end up overtraining or increasing the risk of injury. Embrace the challenges summer presents, and know that properly equipped, you can use the heat to take your fitness to a new level!
*This Article Originally Appeared in the July 2014 Issue of Running Journal