For many, the summertime means leisure travel and the use of accumulated vacation days. Weekends are often spent outdoors and the longer days allow for physical activity later in the evening. Yet there are two sides to the coin of warmer temperatures, as the heat makes exercise more challenging in certain areas of the country. Of course, not every climate brings scorching heat.

Whether comfortable or miserable, the increased warmth impacts exercise. On the one hand, the added strain makes the body work harder and thus burn more calories. However, it may also shorten the duration of the workout. New research suggests the former outcome may be worthwhile pursuit in many instances, according to a feature article from Outside Online.

Story author Meaghen Brown interviewed multiple experts, writing:

Researchers have been looking at the effects of heat on athletic performance for decades, and their results have been consistently surprising. Studies have found that, in addition to an increased rate of perspiration, training in the heat can increase an athlete’s blood plasma volume (which leads to better cardiovascular fitness), reduce overall core temperature, reduce blood lactate, increase skeletal muscle force, and, counterintuitively, make a person train better in cold temperatures. In fact, heat acclimation may actually be more beneficial than altitude training in eliciting positive physiological adaptations, says Santiago Lorenzo, a professor of physiology at Lake Erie College of Osteopathic Medicine and a former decathlete at the University of Oregon. “Heat acclimation provides more substantial environmental specific improvements in aerobic performance than altitude acclimation,” he says. And in contrast to the live low, train high philosophy, we more quickly adapt to heat stress than we do to hypoxia. In other words, heat training not only does a better job at increasing V02 max than altitude, but it also makes athletes better at withstanding a wider range of temperatures.

Athletes can adapt to heat in one of two ways. The first is through incremental improvements in tolerance over time—work out in the heat a little bit every day, and eventually your body will dissipate heat more effectively. The second way is through thermotolerance, which is a cellular adaptation to an extreme heat experience, like suffering such severe dehydration after a run that you need an IV. Essentially, if you shock your system, your body will be able to withstand greater temperature stresses later on. But successful heat adaptation is difficult—and clearly dangerous—to achieve outside of controlled settings. Lorenzo explains that performance gains are possible only when athletes elevate their core body temperature, and without careful monitoring, it’s possible to elevate your core temperature to lethal levels 

When performed safely, however, heat training can have extraordinary effects. 

Although the benefits may be worth the strain in many cases, careful measures should always be taken to avoid overheating and unhealthy fatigue. For practical steps from Cleveland Clinic to prevent this, click here.

To read Brown’s full writeup, click here.