Anaerobic Threshold

The anaerobic threshold is the point where lactic acid starts accumulating in the body. Read on to know how to calculate the anaerobic threshold and what is its significance...

Anaerobic threshold is a frequently used term which many people do not follow. Anaerobic threshold is said to be a very good and reliable indicator of the performance ability of a person in aerobic exercises. To understand the anaerobic threshold definition, one needs to understand what happens when the body requires energy. There are two ways that the body manages to get energy, one is from the aerobic pathway and the other is from the anaerobic pathway. At the end of the anaerobic pathway, lactic acid is formed. When the body reaches an extent where this lactic acid starts to accumulate faster than it can be removed, it is known as onset of blood lactate accumulation (OBLA) or anaerobic threshold. Given below are details about how to determine anaerobic threshold and what is its significance.

How to Calculate Anaerobic Threshold

The most reliable way of calculating the anaerobic threshold is with the help of a graded exercise test done in a laboratory setting. During this test, the person initially starts walking on the treadmill. One can also calculate the anaerobic threshold cycling on an exercise bike. Slowly, the velocity or the resistance of the treadmill or cycle is increased at regular intervals, like after every minute or every three minutes. Blood samples are taken at each increment rise in the velocity. Often at the same time, the maximum heart rate and other physiological kinetics are also measured.

The blood lactate levels are then plotted against each measure of each workload interval. This helps to give the lactate performance curve. It is advisable to record the heart rate at each interval with the help of an electrocardiogram as opposed to a standard heart rate monitor for more accurate readings. After seeing the lactate curve, the anaerobic threshold can be determined. The point on the curve where there is a sudden and sharp rise in the curve above base level is said to be the point of onset of blood lactate accumulation or anaerobic threshold.

If a person is in doubt about the readings he has obtained, then he can do an easy confirmatory test just to be sure. If the anaerobic threshold is said to occur at a speed of about 15km/h when the person is running on the treadmill, then to confirm the reading, ask the person to run for fifteen minutes at a speed that is just below the threshold level, then fifteen minutes at a speed of the threshold and then fifteen minutes at a speed just above the threshold. If the blood lactate then remains steady at 15km/h, then this means that the reading obtained is fairly accurate.

Advantages of Calculating Anaerobic Threshold

It is said that calculating the anaerobic threshold and heart rate helps to train athletes better. This is because the anaerobic threshold for untrained people is very low whereas the threshold for trained athletes is high. This is because if there is accumulation of lactic acid in the muscles, then the muscle gets fatigued and are unable to move. Furthermore, it is said that the anaerobic threshold is somewhere between 90 - 95% of the heart rate. Thus, people tend to train so as to increase and prolong their anaerobic threshold. For this purpose, athletes go in for interval training, which tries to take advantage of the body being temporarily able to recover when it is just below the anaerobic threshold. This is the way that endurance strength training exercises are planned.

The anaerobic threshold is an important and helpful indicator, not just for athletes, but also for people who wish to increase their endurance levels. So, if you exercise regularly and eat right, you will definitely be able to increase your anaerobic threshold, which will ensure that you reach your desired level of fitness.