The Critical swim speed test offers you a method to define your swimming training zones without the need of lactate measurement.
iQO2 calculates your training zones based on your fastest times over a 200m and 400m swim test. Perform the 400m test first, as it's likely to affect your 200m test. Recover completely between each test with some easy swimming. You can enter the values of your best times over 200 and 400m (mm:ss:tt).

 The Critical swim speed test training zones are expressed as:

• heart rate values - bpm
• swimming: pace values - mm.ss/100m

Learn how to create new training zones with the Critical swim speed test.