We need to remember that although we South Africans are acclimatized to high temperatures and humidity over our summer months, the temperatures do keep rising over Christmas and the New Year. It's important to know how the heat will affect us 'exercise bunnies' that just can't put a halt to their exercise routine over the summer.
The response to exercise in the heat is determined in part both by the intensity of the exercise and by the degree of heat stress. At the same power output, exercise in the heat results in higher heart rate and a higher cardiac output, as well as higher core and skin temperatures.
Both dehydration and exposure to heat, even without exercise may result in a variety of symptoms, including headache, nausea, dizziness, and a sensation of fatigue. Therefore in order to try to avoid the disadvantages of exercising over Christmas and the New Year, it may be important to rethink your training schedule so that you avoid the hottest part of the day which is around noon, and exercise either early in the morning or later in the day.
Also not drinking enough water to replace sweat losses will severely impair your exercise capacity and will increase the risk of heat illness. Sweat losses during training can add 0.5 – 3.0 liters per hour depending on training intensity, the clothing worn, the climatic conditions, and characteristics of the individual.
Consequently, consider these factors whilst also replacing your body with fluids during your training, especially if you are a road runner who is exposed to heat for prolonged periods.
So don't be silly this season, stay hydrated and out of the midday heat.