When you leave the house in t-shirt and shorts in the morning and after ten minutes you start wishing that you had a replacement t-shirt in your bag, you know that summer has begun. Dripping of sweat and wishing for a cool pool, a shady place, a refreshing drink and an evening with a barbecue and friends. It’s easy to decide then whether or not you would prefer a relaxed afternoon or to train under burning hot sun. However, on day 2 you start questioning how to go on with your workouts. Taking a break until the weather gets colder again? This is quite out of the question for real athletes… So if you don’t have an air-conditioned gym where you could do your workout on hot days, you need another strategy to handle the heat.
There’s nothing bad about a bit of heat!
Warm temperatures also have their advantages. If the body is already warm, then the warm-up can be shortened a bit. To maintain a body-temperature of about 36-37 degrees, blood vessels expand to faster conduct away body-heat. As a consequence blood pressure drops and the heart needs to pump harder to keep things working. This costs energy. Simultaneously the body switches on its own cooling system. Sweat leaks out of more than 3 million tiny glands in the skin – as soon as it vaporizes, it cools on the body and therefore helps to keep the temperature at a healthy level. An athlete achieves averagely 1.8 litres of sweat per hour. The higher the ambient temperature and humidity rises, the more difficult it is to get the body to regulate its blood heat. The fluid depletion goes up to about 3 litres per hour! It is clear that the body has more important things to do now than to care about effective training. The research group endurance of the Swiss Olympic Association discovered that a fluid loss of 2 percent results in a reduction of VO2Max (the maximal oxygen absorption) of 10 percent and performance of 20 percent. According to this, an athlete with a bodyweight of 70kg would lose more than 4 percent of fluid with 3 litres of sweat… and would have lost over 40 percent in performance!
Golden rules for training in the heat
1. With an air temperature of 30 degrees or more, outdoor training isn’t a good idea. Adjourn your workout to the early morning or the evening, when it’s a bit cooler again. The body needs about 4 to 5 days to acclimatise. Make sure that you fall back on less intensive and shorter workouts until then. Since the pulse is obviously higher in the heat with equal strain, you should accordingly adjust the training intensity – you don’t always need a new personal best! It’s not just your cardiovascular system that is glad about some days with a focus on technique instead of pace. If you stay on a cooler place right before working out (e.g. a flat) or take a cool bath (about 24 degrees water temperature), then the body isn’t already warmed up for when you start your training. This helps you to sustain the capability a bit longer while training in the heat.
2. Don’t forget the ozone pollution! The “summer smog” is an outgrowth of the reaction of UV radiation with nitrogen oxides and hydrocarbons, and it does not only occur in cities but especially in the peripheries and in flat country. Ozone is nothing else than an irritant gas – it causes inflammations in the tissue and irritates mucous membranes and nerves. With more than 200ug/m3 the endurance performance is significantly affected and the training should be better relocated indoor because of health concerns.
4. With rising temperatures, the consumption of carbohydrates under strain rises as well. If you train too hard and intensive now without refilling your glycogen stores then you will affect your performance. After training, try to include some carbohydrates in your menu – of course preferably the full-valued ones of fruits, vegetables and whole grain products. Another tip for competitive sportsmen: Studies have shown that two-week high fat diets push the body to burn more fat and less carbs under strain. As the body releases more glycerin in this way, fluid is better retained in the body.
5. It’s perfectly clear that you need to dress adequately for training in the summer and protect yourself. Don’t forget to use sunscreen and choose light and ideally bright clothing. Also a head-covering is recommended for outdoor training. If you want to cool your body, you can dip your shirt into cold water and wring it out. Have in mind to change wet clothes or slip something on before moving to air-conditioned rooms otherwise you might easily catch a cold! After intense strain the immune system is weakened for a while and you might fall ill easier.
However, the most important rule of all is this: “Listen to your body!” If you suddenly feel cold instead of hot, if you feel dizzy or sick, stop training, go indoors and refill fluids and electrolyte stores. There’s one thing always more important than any workout: your health.