Anaerobic means ‘without oxygen’. Anaerobic threshold is the point where lactic acid starts accumulating in the body. The following article provides information on how to calculate the threshold and the benefits of this calculation.
The term ‘anaerobic threshold’ is frequently used in the medical arena. It is considered to be an effective and reliable indicator of the ability of a person to perform aerobic exercises. To understand this terminology, one needs to understand what happens when the body requires energy. There are two ways that the body manages to get energy from: one is aerobic pathway and the other is anaerobic pathway. Lactic acid is formed towards the end of the anaerobic pathway. When the body reaches a particular limit, lactic acid starts to accumulate faster than it can be removed this limit is known as the onset of blood lactate accumulation (OBLA) or anaerobic threshold.
The most reliable way to calculate OBLA is a graded exercise test that is done in a laboratory setting. During this test, the person initially starts walking on the treadmill/cycling on an exercise bike. At regular intervals, the velocity or the resistance of the treadmill or cycle is gradually increased. This interval could vary from a minute to 3 minutes. Blood samples are collected, and the maximum heart rate and other physiological kinetics are measured at each interval. The blood lactate levels are then plotted against the measure of each workload interval. This gives the lactate performance curve. For more accurate readings, the heart rate at each interval could be recorded with an electrocardiogram, and compared against a standard heart rate monitor. This threshold can be determined after observing the lactate curve. The point on the curve, where there is a sudden and sharp rise in the curve above the base level, is said to be the point of OBLA.
If there are doubts regarding the readings obtained, then an easy confirmatory test can be performed. For example, if the anaerobic reading reflects to have occurred at a speed of about 15 km/h, then to confirm the reading, a person could be asked to run for fifteen minutes at a speed just below the threshold level, then fifteen minutes at a speed of the threshold and lastly, fifteen minutes at a speed just above the threshold. If the blood lactate still remains steady at 15 km/h, then it could be confirmed that the reading obtained is fairly accurate.
Advantages of the Calculation
It has been observed that calculating OBLA and heart rate is helpful while training athletes. The threshold for untrained individual is very low, when compared to the threshold for trained athletes. If there is accumulation of lactic acid in the muscles, then the muscles get fatigued and the athletes are unable to move them. The threshold is determined to be between 90 – 95% of the heart rate. Athletes are trained in order to increase and prolong their threshold. Therefore, they are recommended to go in for interval training, wherein, when the body is just below the threshold, the body state of ‘being able to recover temporarily’ is utilized. Endurance strength training exercises are planned on these lines.
This threshold is an important and helpful indicator, not just for athletes, but also for people who wish to increase their endurance levels. So, by exercising regularly and eating right, one will be able to increase their threshold, and eventually achieve the desired level of fitness.
Disclaimer: This article is for informative purposes only. Always consult a physician before starting any physical fitness program in order to reduce the risk of injury.