Once Inspired

Understanding anaerobic threshold and applying it to your training will make you a better athlete.

Simply put:

VO2 max (aerobic threshold) is the level at which your body cannot increase its intake of oxygen no matter how much the exercise intensity increases. If your VO2 max is your aerobic potential then you anaerobic threshold determines how much of that you can tap. Exercise beyond this point is known as anaerobic (without oxygen). This results in high levels of blood lactate. At this stage blood lactate cannot be removed at the level at which it is produced which causes an excess of blood lactate. For most, blood lactate starts to accumulate at a level much lower than VO2 max. The point at which blood lactate build up occurs is known as your anaerobic threshold.

Anaerobic Threshold occurs at different exercise intensities for different people. It is expressed as a percentage of your VO2 max.

With the help of the “hypothetical” graph below allow me to explain in greater detail.

After testing an athlete’s Vo2 max is 55.0 mL.kg.min at a speed of 16.48 km/h. That means that he/she will not be able to run at 16.48 km/h for very long, 10min at the most. This athlete’s blood lactate begins to accumulate at 33.75 mL.kg.min or 65% of his/her VO2 max. At 12.5km/h he/she can run for a prolonged period. This is because there is no lactate build up at that speed.

By applying specific endurance training to your training regime you can improve your anaerobic threshold. This won’t slow the rate at which lactate accumulates; it will simply delay its onset, allowing you to tap more of your VO2 Max.

There are a number of ways to determine your anaerobic threshold. 1 way is to get it tested at a sports science facility and the other 2 you can do on your own.

The first of which requires you to run or cycle for at least 20min. Gradually increase your speed until you reach the point at which you feel you can’t go on much longer. Jelly-legs are a common symptom. Note your heart rate at this point. This is your anaerobic threshold.

Another DIY method is to run or cycle at the highest intensity which you can maintain for 1 hour. Your average heart rate for this will also be an indicator of your anaerobic threshold.

If you feel compelled to try both of these tests, they may differ by a few BPM but that’s okay. These 2 methods are surprisingly quite accurate and are enough to help you (or your coach) plan your anaerobic training sessions.

Anaerobic Threshold training is fairly uncomplicated once you’ve determine your target heart rate zone. These training sessions should be performed at or just below your anaerobic threshold and can be performed as intervals or as continuous training.

Interval training should consist of 3-5, 6-12min intervals with a 2-3min rest period in between each interval. Ideally you should reach your target heart rate within 1 min.

A continuous anaerobic threshold session is more demanding and should last 20-45min. This should be performed twice per week, but not more.