Kenneth Gardner
IF YOU exercise too hard or for an extremely long period of time without any rest you will feel tired or worn out. When you feel so tired that you cannot continue an activity, you are experiencing fatigue. Many of us experience fatigue for a number of different reasons physical work or exercise is not the major causes of fatigue, it is the underlying factors that impact the way you cope with the physical exertion.
Fatigue is the way your body reacts to situations that it cannot cope with. It is a way that your body sends messages to your brain to alert you to take precautionary measures to avoid imminent danger.
There are five major factors that cause fatigue when you exercise:
1. The build up of waste substances in your body
2. Low energy supply.
3. Loss of excess water
4. Overheating of your body
5. Mental fatigue
These five factors can be managed quite successfully so that your exercise can be enjoyable and beneficial.
When we do physical exercise or physical work our body produces waste material at a faster rate. This can lead to a build-up of waste material in the different body systems which can result in the development of fatigue. However, as your fitness levels improve as a result of the exercises that you do, your body becomes more efficient, it learns to do more work by using less energy and so produces less waste material. The waste material also takes a longer time to build up; this slows down the development of fatigue.
The food that provides you with your energy supply is used more efficiently by your body as your fitness levels improve. Your body is able to do more work with less energy or your metabolism is more efficient. By improving your fitness and participating in physical exercise your body will take a longer time to experience fatigue. You can function for longer on lower levels of energy supply before fatigue sets in.
The loss of excess water by the body can be experienced very easily during physical exercise. By drinking adequate amounts of fluid, you maintain the water balance in your body. It is necessary to start the exercise well hydrated, and by drinking fluids during and after the exercise, fatigue can be delayed or even prevented from the standpoint of excess water loss.
BODY TEMPERATURE
Your body has a certain temperature at which it functions best, that is, your normal body temperature. If that changes too much or gets too high as you could experience from physical work or exercise, fatigue will be experienced. This is related to the loss of excess water. However, as your fitness improves via physical exercise it will take a longer time during exercise for your body temperature to increase to excessive levels. Similarly, fatigue can be delayed or avoided.
Mental fatigue is a major factor in the overall fatigue that the body experiences. By exercising too hard or even not enjoying the activity that you are doing, you can feel mentally tired. Mental fatigue is an indication of your mind's inability to cope with the mental challenges it faces. Interestingly, mental fatigue can also be eliminated by doing physical exercise. However, by improving your physical fitness, the brain also benefits as its ability to manage mental stress is improved. Your mental strength is improved, thus mental challenges are better managed.
Kenneth Gardner is an exercise physiologist at the G.C. Foster College of Physical Education; email: yourhealth@gleanerjm.com.
