The Anaerobic Threshold (AT)(also called the onset of blood lactate accumulation (OBLA) is defined as that intensity of effort (speed) above which lactic acid starts piling up in the muscles and blood. This piling up is due to the fact that the removal of the lactic acid can no longer keep up with your production. This anaerobic threshold is therefore the transition from the aerobic - to the anaerobe lactic energy supply system. The later an player reaches this threshold, the better its endurance.
Work below the anaerobic threshold can be continued at a longer period of time (at least 45 minutes). Work with an intensity above the anaerobic threshold will be much shorter. With the lactate acid levels increasing, the acidity of the of the muscles and blood increases, this influences the performances negatively. Rugby is a high intensity sport, you have to develop the player's anaerobic energy supply system and the efficiency of the player's body in the lactic acids tolerance and removal. In order to do this you have to know the anaerobic - or lactate threshold. This is also know as HIT: High Intensity Training.
There are several ways to determine the anaerobic threshold based on the maximum heart frequency:
- Maximum heart rate using heart monitors
- 220 - age rule
- Drop of from a 200 meter intervals
There are all kinds of fancy lab tests requiring expensive equipment. My point is that you the coach should develop a trained eye! Look for shortening stride length and knees that do not go up as high into the stride anymore to recognize lactate acid levels rising.
Running these tests below will help you develop that sense.....
1. Based on the maximum heart frequency
Maximum heart rate monitors
Based on one's maximum heart frequency one can consider 70% of the maximum heart frequency as minimum and 90% of the maximum heart frequency as maximum threshold. The maximum heart frequency is simply determined with the use of a heart rate monitor and a standardized test. When a player is carrying a heart rate monitor you can check if his work rate was below or above his anaerobic threshold.
[note: the test mentioned below is not advised for adults who had no thorough medical check and certainly not for people with a risk on carrying heart diseases. Players who are just starting a program have to be assisted by someone with experience.]
The 220 - ages rule
A lot of people use a theoretical maximum heart which is based on the formula 220 minus the age (in years). On this theoretical value the 70% and 90% are then calculated and used as minimum and maximum heart frequency. For us rugbycoaches this comes down to:
- 20 yr. old: max heart rate = 200; HIT area = 140 - 180
- 30 yr. old: max heart rate = 190; HIT area = 133 - 171
(You will see how difficult it is to work in this area)
This approach is perhaps useful for a very general program in the fitness center, but is not certainly accurate enough for your work with players. You want to train and progress in fitness, and better test methods are necessary.
Field test for finding the maximum heart rate
Do a low intensity warming-up of at least 10 minutes. Next, bring up the intensity for every 10 or 30 seconds. Meanwhile continues to follow the heart rate on the heart rate monitor carefully. When the players starts to dig deep and becomes heavily fatigued they should give it their last go with a final sprint.
Read the heart rate from the monitor immediately after concluding the effort. Walk or jog, do not lie down or sit after this maximum effort test.
2. The Conconi Test
Another test to determine the anaerobe threshold is developed by Conconi. He based his test on the basic rule that the heart frequency increases linearly with increasing load, to divert from this line on a certain point.
The dots on the chart below reflect the heart rate measured on the 200 meters interval on a athletics track of 400 meter. The player runs each subsequent 200 meter 2 seconds faster until exhaustion sets in (and the required speed can be no longer maintained). The point at which the heart frequency no longer increases linearly is the anaerobe threshold. Conconi also performed lactic acid tests that confirmed the method.
This method has been questioned scientifically because several other research workers could never get the results to those Conconi presented. This method is thus not really reliable.
- Wikipedia and anaerobic exercise