By Axt, Peter; Axt-Gadermann, Michaela
Nutrition Health Review , No. 91
Even we-two people who used to be dedicated long-distance runners-are no longer completely convinced that athletic exercise is healthy! In exercise, it does not hold true that "a lot helps a lot." Exercise, physical labor, and heavy exertion create an "emergency situation" for an organism, in which it reacts in the same way it does to other stressors. In order for our body to complete the exercise tasks we require of it, it must put the same mechanisms into motion that it does in any other stress situation. The adrenal glands secrete cortisol in order to prepare enough energy for the physical task. As a result, the blood sugar level rises. Stress hormones like adrenaline and noradrenaline increase the pulse and blood pressure in order to ensure adequate nutrition of the organism even with the increased exertion. Our breathing grows faster in order to pump more oxygen into the organism.
If the exertion, and the associated stress to the organism, is light and of relatively short duration, and if the organism has enough time to regenerate, then there is no damage to the body.
Endurance sports, on the other hand, create constant stress episodes and, in the long term, appear to cause changes in the way the organism regulates stress. If practiced with a focus on endurance and results, recreational sports appear to be as damaging as constant stress at work-a conclusion reached by Horst Meermann at the Max Planck Institute for Psychiatry in Munich [Germany]. The subjects of his study were older marathon runners (average age 55) who had been running marathons for at least 10 years and covered between 75 to 90 miles (120 and 150 km.) a week when in training. Blood tests showed that the continual intensive physical exertion led to an overproduction of the stress hormone cortisol in the runners' adrenal glands. …