It is well documented that many of the world’s best distance runners live or train at altitude part of the year. While spending weeks at a time away from home at altitude training camp is commonplace for many American professional runners, it’s an impractical luxury for most of us. And while the thought of escaping to the cool mountain air during the summer is tantalizing, research has shown heat training to have similar performance benefits to altitude training. The mechanisms that lead to those performance benefits differ, but the keys to reaping the benefits of both are strikingly similar.
Heat vs Altitude
Just like altitude, training in summer heat and humidity can just as easily break you down as it can build you up. The first 10-14 days of hot weather is the acclimation period where the weather hits you the hardest. The warm days that cause us to wilt in April and May feel like a cool fall days by the time July and August arrive because of that acclimation process. That’s not to say running in hot weather ever is easy as running in cool, dry conditions, but once you’re acclimated your body does manage it better. When athletes go to altitude for the first time the adaptation period can take up to 3-4 weeks, but the initial dip in performance is similar to that of adapting to the heat.
According to Dr. Robert Chapman, the Associate Director of Sports Science and Medicine who oversees altitude-training camps for many of American’s best distance runners, “training intensities and volumes should be adjusted (reduced) to avoid over training and allow better acclimatization.” He could have just as easily been dispensing advice about heat acclimatization as altitude acclimatization. The thought that the summer heat could actually improve your performance sounds so foreign because few heed that piece of advice.
Training in the heat and humidity will slow you down just like altitude will, and if you don’t adjust your training appropriately you’re at high risk of over training. Acclimating to the heat doesn’t make training in the summer easy, and it doesn’t mean your races in the heat will suddenly be faster than fall or spring, but it does mean that if you adjust your training properly your fitness can benefit greatly. East African athletes who have lived at higher elevations for generations still run faster at sea level than they do at altitude, and unfortunately no matter how well acclimated you are to heat and humidity you’ll still run faster in cool weather.
The late Dr. David Martin was one of the exercise physiologists responsible for the heat-training program marathoners Deena Kastor and Meb Keflezighi followed ahead of the 2004 Athens Olympic Games where both medaled in the marathon, and he advised people to avoid hard workouts if the combined heat and humidity was over 165. In those conditions your body can’t effectively dissipate heat and you’re likely to do more harm than good by attempting a high intensity workout.
Dr. Jack Daniels, one of the leading exercise physiologists in the history of long distance running, has a useful online calculator for adjusting your paces on warmer days. However, no calculator or training plan can be inside your body. You know your body better than anyone, and being able to understand the effort you’re putting out in a way that is independent from pace is critical to managing heat and humidity. Easy days must remain at a conversational pace, even if the pace is slower than what you think it should.
One training adjustment you can make to keep from over cooking your workouts is to shorten the intervals you’re running. If you’re scheduled to do a long tempo effort on a hot and humid afternoon you’re better off breaking the workout into tempo intervals. With long, steady workouts it’s very difficult to keep your core temperature from soaring on hot and humid days. Adding some short recovery pieces can keep your effort in the right place overall. For example, try breaking a 30-minute tempo run into 5 x 6 minutes with a slow 75-90 second recovery jog between each. The recovery jog will help bring your heart rate down a little bit so it doesn’t continue to climb as it works harder and harder to cool your body. In those instances it is very easy for a tempo workout to turn into a race effort. You can also lean more heavily on workouts like fartleks and hill repeats during the summer because in addition to having rest intervals, they are also structured to be more effort based than time based.
Another more obvious key to managing summer training is staying properly hydrated. This is true of altitude training as well due to increased ventilation and drier air. Being chronically dehydrated will impair your performance but also your ability to recover day to day. It’s good practice, especially in the southeast, to weigh yourself before and after your run each day. Aim to replace every 1-pound of weight lost during your run with 16 ounces of fluid. You’ll also lose electrolytes like sodium, potassium, magnesium, and calcium through sweat. It’s important to replace electrolytes along with water to maintain proper fluid balance in the body.
Managing recovery is critical during the summer because the heat and humidity are an added stress placed on our bodies, on top of the stress of daily training. Managing the environmental stress is where most people falter in the summer. We’re used to managing the training stress, but once summer hits we do a poor job of taking into account the impact environmental stress has on our training. However, with the proper adjustments to training intensity, attention to hydration, and a focus on proper recovery the summer heat can help take your performance to the next level.
*This Article Originally Appeared in the July 2018 Issue of Running Journal