While it is true that most of us are not sports people/athletes, we are similar in that we also reach the same level of fatigue because of our various daily lifestyle stressors, such as lack of sleep, stressful jobs and poor diet, to name but a few. Unlike athletes, though our symptoms are not likely to be limited to just fatigue. Other symptoms are colds and flu's, allergies, aches and pains etc. Stress is normally viewed as a negative however we need stressors for positive effects on our health. An example of a good stress is that of exercise which is needed, for example to help us maintain an ideal weight, have strong bones and keep us flexible and mobile. The bad stress of exercise can be that of over training, which can cause injury for example. Indeed lack of exercise would also cause a stress to our body. The diagram below shows how these lifestyle stressors affect our health.
May Allah (swt) grant you all the best of health.