Exercise in the heat: A blend of science, hazards and tips

cycling in the heat TDF-1961I got inspired to write this article since I am going back home soon and I am more than convinced that the first thing that I am going to experience stepping off the plane will be the heat wave straight on my face. From that point on and at least until mid October I will have to adapt my daily life routines to the average temperatures of 35C and sometimes even more than 40C. Probably, on some extremely hot days it will be unbearable to perform any kind of outdoors exercise. However, as a regular runner I want to stay physically active and perform all my favorite workouts during the summer months without putting my health at risk. Based on some scientific studies, there are several methods that make it not only safe but also lead to performance enhancement in the heat. Moreover, new products in food and clothing industry are also aiming at performance improvement and safety during exercise in the heat.

In the recent study at California State University researchers examined the effect of oral rehydration and external cooling on physiology, perception, and performance in hot, dry climates. Based on the study design, ten male runners completed four trials of 90 min briskly walking at 30% of their VO2max, followed by an all-out 5-km time trial in 33°C. On one of the experimental days, the runners exercised without receiving fluids of any kind. On another day, they drank water, chilled to 6 C, every 10 minutes. Yet in another session, scientists poured glasses of similarly chilled water over the volunteers’ heads every 10 minutes, so that it dripped down their faces and necks. Finally, the volunteers were in the trial of both, drinking the cold water and having it splashed over their heads. The main finding of the study was that independent of oral dehydration, pouring cold water on the body benefited skin temperature, thermal sensation, and RPE during low-intensity exercise in hot, dry conditions but failed to influence high-intensity performance. In other words, when cold water was poured over their heads the runners did report feeling blessedly cooler than in the other exercise sessions. They also reported that the workout felt noticeably easier, and their skin temperatures were lower than in other sessions. However, they didn’t perform better during the 5 km time trial, no matter what cooling strategy they employed. Their performances were generally equivalent, whether they drank cold water, were doused with it, or neither. What these finding suggest is that pouring cold water over yourself is going to make exercise in the heat more tolerable and it will make you feel better, but you will not necessarily be faster.

However, as regular exercisers it will be more than “unwise” to employ cooling strategies that in any way subvert the body’s own innate heat-monitoring system. In other words, if pouring cold water over your head somehow allowed you to exercise harder without feeling unbearably hot, you might wind up running yourself into serious heat illness. Under normal exercise conditions our body (e.g. skin, blood vessels, perspiration) adjust to the heat. But our homeostatic system may fail if we are exposed to hot and humid environments for too long. Heavy sweating rate and inefficient fluid replacement might result in heat-related illness.  Heat-related illnesses occur along a spectrum, starting out mild but worsening if left untreated. Heat illnesses include:

Muscle cramps                                                                                                                             Muscle cramps are involuntary painful muscle contractions, mainly affecting the calves, quadriceps and abdominal. Some of the causes of muscle cramps are: a) straining or overusing a muscle, b) dehydration, and c) lack or depletion of mineral in our body. At that first phase your body temperature may be normal.

Heat exhaustion                                                                                                                               With heat exhaustion, your internal body temperature rises as high as 39 C. When a heat exhaustion strikes you, you may experience headache, nausea, vomiting, fainting, weakness and cold clammy skin. Heat exhaustion is a serious medical condition and if left unthreaded can lead to heatstroke.

Heatstroke                                                                                                                             Heatstroke is the next stage after a heat exhaustion state. Heatstroke occurs when your internal body temperature raises over 40 C. Your skin maybe hot, but your body may stop sweating to help cool itself. You may develop irritability and confusion. Heatstroke is a life-threatening emergency condition and you need immediate medical attention.

Protection tips

Fluids replacement                                                                                                                         Most of the times, water consumption in not enough. Sports drinks rich in carbohydrates and electrolytes are recommended. If you are training for more than 45 min, I would recommend to use electrolytes replacement tablets or salt tabs that can pop in your sports bottle.

Clothing                                                                                                                                               You should wear light-coloured clothing, consisting from non-cotton fabrics.  The best solution is to wear dri-fit athletic clothes. The idea behind dri-fit clothing technology is that   moves moisture to a fabric layer away from the skin where it can evaporate. This leaves the skin protected, comfortable and cool.

Sunglasses                                                                                                                                   Looking cool is not the only reason to wear sunglasses while you exercising in the sun. A good pair of sunglasses can protect your eyes from ultraviolet (UV) radiation. In addition, they will protect you from dust and sand when you exercising under windy conditions.

Summing up, you should always attempt to protect your body avoiding any kind of cheating strategies over your homeostatic system and by following some basic cooling strategies. Try to stay well hydrated, wear the appropriate clothes and most importantly try to avoid exercise during the day when peak temperatures occur.

About Anastasios Rodis

Anastasios Rodis is an exercise physiologist at Aspetar Orthopaedic and Sports Medicine Hospital in Qatar. Anastasios holds a European Masters in Sport and Exercise Psychology (Lund Universitet, Sweden/Leipzig, Germany). He has also completed an M.Sc in Applied exercise physiology (University of Bangor, wales, UK) and a B.Sc in Sport Sciences (University of Portsmouth, UK). Anastasios has 15 years of athletic history in track and field. He has worked as a sport psychologist with elite Swedish swimmers. He has also efficiently cooperated as an exercise physiologist with Panathinaikos football club and worked with elite athletic teams, individual athletes as well as patients with musculoskeletal injuries. His main focus is the promotion of exercise and healthy lifestyle by using and combining both physical and mental techniques.
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1 Response to Exercise in the heat: A blend of science, hazards and tips

  1. Jodi Murphy says:

    Young athletes are especially susceptible to dehydration and heat illnesses. I also read somewhere that because we are so used to air conditioning it takes longer for our bodies to adjust to the heat outside, making it even easier to over heat.

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