Yesterday I attended a BASES workshop focusing on critical power. Essentially it is a performance measure that gives a level of training intensity that is maintainable for somewhere between 20-40 mins. Theoretically it should be the same as your maximum lactate steady state (MLSS) but it tends to sit a little higher in the severe intensity domain. However, those utilising it tend use a further zone classification between the heavy and severe zones, imaginatively titled the ‘very heavy’ zone.

The test itself requires three maximum effort tests of varying lengths between 3 and 15 minutes long (3, 7 and 12 minutes seem to be the most common). These tests usually take place on the same day with 3 hours recovery between each one. With the average power data you can plot a graph against time and get a measure  of critical power.

The measure lends itself particularly well to cycling given the familiarity with wattage as a measure of training intensity, however it is possible to take the tests using a set distance or time that is more applicable to runners and swimmers where taking of MLSS is very difficult to achieve. The information is very communicable to athletes given the graph produced and units are simple to understand. The value is also great to use for prescription of intensities when designing training sessions.

A certain amount of familiarity needs to be developed with the test in terms of pacing strategy which can skew early tests (those who’ve used the cooper test will be familiar with this) and the large recovery periods and requirement for full day to test could make the test inconvenient compared to a MLSS test which essentially gives a similar measure. It was mentioned that it had been trialled within an hour with similar results to the full day testing. If this proves reliable then I think the test becomes much more usable, primarily in cycling and swimming.

An important part of working with any athlete is testing. It is necessary to set a baseline against which you can compare to mark the progress of your athletes. Sometimes, it is not possible to perform the test you want to, usually because of equipment/funding issues. To get in the lab and take measurements of VO_2max and/or lactate threshold is the ideal scenario for endurance athletes. It enables a coach to give very accurate prescription of training zones as well as being a valid and reliable test to repeat further down the line to test progress.

Today I made use of the cooper test in order to give a prediction of VO_2max, the test can be done either measuring distance completed in 12 minutes or measuring the time it takes to complete a 1.5 mile run with different prediction equations for each. It went well and athlete being tested worked hard but it did raise a couple of issues for me.

The test is fairly dependant upon the pacing strategy of the athlete meaning that the more times the test is run the better the athlete is likely to do, purely as they become more adept at performing the test. On this occasion the athlete was used to the distance and associated pacing. The second issue was the prediction value, error scores can be anything up to 10% which is a huge amount providing big issues with the retest score.

Despite the issues, the test gave a ball park score for VO_2max which the athlete was happy with and it is still a useful test to monitor performance. The difference in time to completion will give a measure of progress that will provide data on the effectiveness of the training program. It would be good to hear any other views on prediction tests or other tests people have have used for aerobic performance…

Here’s a taste of what you need if you fancy it.