Critical swim speed

When purchasing, downloading or borrowing a swimming programme, or when you attend a coached lane at the local pool, have you ever wondered what all the jargon means? Ever wondered how the coaches and swimmers alike all know how to pace themselves, and at what intensity they ought to train? Apart from endless miles in the pool and one to three hours per week land training, how do they achieve split times, race pace, swim rest ratios and how do they make it look so easy? Brian Fernie explains:

Swimming in this respect is not much different from many sports. Whether you are recreational, a club triathlete or an elite swimmer, it all boils down to the same things when you are swimming. Stroke technique Stroke count Aerobic conditioning Anaerobic endurance Land training Mileage in the pool Type of stroke Many of us have tried, and died, trying to swim 400m straight away. Many of us have wondered what 'onset blood lactic tolerance' and 'swim rest' mean. Fear not, in this article we will look at the critical swim speed test, who can do it, and what you need to do it (apart from big lungs).

The test was devised by E Ginn in 1993 and is used by coaches and swimmers alike to test aerobic fitness that can be maintained. From the test results, Ginne concluded that training times could be calculated and set for swimmers using his unique/specific calculations. This means that swimmers can train just below 'race pace' or at 'lactate threshold', to give it it's other name.

Who can do it? Anyone who wishes to improve their aerobic swimming capacity should be capable of carrying out this test - it's also something that can be done as part of a group session where everyone can help each other with the timing and counting. What do I need? Apart from the obvious, a pool to swim in - size doesn't matter although 25m or 50m is best - you need some basic equipment: a stop watch to time the swim, someone to act as a lap counter and a calculator.

Test criteria The test needs to be carried out in the same way each time so there are some basic criteria: Must be from a push start; no diving is permitted The swimmer must be allowed to fully recover from each swim Record the time for each swim in seconds and calculate by the method shown below The test itself comprises two swims over 400m each and two swims over 50m each.

The best method to do this is to swim a 400m, rest and then swim a 50m. Now rest and repeat the two swims. You will now have two sets of data for the following calculation. D1 is 50m, D2 is 400m, T1 is the time for 50m recorded in seconds and T2 is the time for 400m recorded in seconds. The formula for the calculation is this: CSS = (D2 - D1) ÷ (T2 - T1) To give an example; Flipper swims 50m in 35 seconds and 400m in 297 seconds so: CSS = (400-50) / (297-31) CSS = 350/262 CSS = 1.32 metres/second What now? Remember the results of the test can only be compared to previous CSS tests. With the correct conditioning, training and stroke technique between the tests, you will be able to see how your training is leading to an improvement in your aerobic capacity or, on the other hand, it could highlight failings in your training regime.

After collating and analysing the test results, how can we incorporate the results into our training schedule? Well that’s the easy part. We can use the results to determine our training times.
For example, Bob's training plan requires him to swim 6 x 400m, so the time it should take him can be calculated as follows: 400m training time = distance/CSS Bob has a CSS of 1.35 meters per second so the calculation is as follows: 400/1.35 = 296.3 seconds = 4 minutes 56.3 seconds for each 400m swim

Does it work? While the reliability of the test results depend on the test criteria and commitment of the athlete, the CSS test itself has proven to be a valid and reliable measure of a swimmer's aerobic capacity. Ut has been rigorously tested by its inventor, who determined that the CSS for a swimmer was about 80 to 85% of maximum 100m swim speed and 90 to 95% of their 400m swim speed. This test will enable you to improve your aerobic fitness and incorporate the results into your training programme.

Remember, tests should always be conducted under conditions as close as possible to the previous test and over-testing can give poor results. Every six weeks is enough to test whether your programme and training is progressing or not. References Ginn, E. (1993), The application of the critical power test to swimming and swim training programmes, National Sports Research Centre Ginn, E. (1993), Critical speed and training intensities for swimming, Australian Sports Commission