determine T30 SWIM PACE

The renowned physiologist Jan Olbrecht, first developed the concept of 'T30'. This is the swim pace that you could hold for approximately 30 minutes in a time-trial environment. He was able to demonstrate (Olbrecht et al., 1985a significant correlation between T30, and a blood lactate concentration of 4mmol/l. Although there are certainly individual differences, 4mmol/l will typically coincide with what we term - the Anaerobic Threshold (AnT).

In the Tri-High Performance system, training levels for swimming are determined by percentages of your 'T30' Threshold Swim pace. However, depending upon your swim ability, pool availability or phase of training, it is not always possible or practical to execute an uninterrupted 30 minute swim.

Therefore, we recommend choosing a shorter TT distance that will be easily repeatable for future assessments. Although a calculation based upon a shorter duration, will have a greater level of uncertainty, consistency from one assessment to the next, is far more important than absolute precision.


Using the links below, you will find equivalent T30 paces from 6 time-trial distances, ranging from 800 to 3000m/yd. Finish times are provided between 10 and 35 minutes (and between a T30 range of 1:00-2:30), however, in the interests of minimising uncertainty and increasing repeatability - we recommend using a distance that will take you between 15 and 30 minutes to complete.

Please note, although swimming a set distance will typically yield better results (a faster pace), if you would prefer to determine your T30 pace from a duration based swim of exactly 30 minutes, then you can of course do so.