Fatigue is when you can't maintain a specific power, speed or output. All athletes experience fatigue whether it’s soccer players unable to sprint to the ball, basketball player not getting height in their jumps, or tennis players losing control of their swing.
Why does it occur?
During explosive activities lasting between 30 seconds – 30 minutes, your body can’t keep up with the lactic acid already in your blood stream and with the lactic acid production. The gradual increase of lactic acid will reduce the ability of your muscles to continue high-intensity exercise. The burning feeling is a sign of increased lactic acid levels, this is a built in safety mechanism to help prevent muscle cells destructing.
When exercising more than 1 hour, fatigue may develop because muscle glycogen stores are depleted.
When exercising for more than 3 hours, it is likely that your glycogen stores have been exhausted and stored fat will supply most of your fuel.
How to delay fatigue?
There are two ways that you can delay fatigue. One is to ensure that your glycogen stores are full before you exercise. The greater the glycogen storage you have, the longer you will be able to maintain your exercise intensity. Another way is to reduce the rate at which you use up muscle glycogen. This can be done by pacing yourself and ensure that you slowly build up your intensity.
What is glycogen?
Glycogen is mainly stored in the liver and muscles. When you fuel, your body breaks down the carbs from your food during digestion and converts the carbs into glucose. Your body will use the glucose right away and will store the remainder in your muscles.