Critical Swim Speed (CSS) Test

Triathlon swimming is about endurance, not raw speed, and we need to train for this. In running or cycling training we are taught to find our threshold power (or pace) and then progressively increase our time on or about this measure to improve our ability to perform under pressure. Working at threshold is about aerobic endurance - in fact, threshold is often defined as “an athlete’s fastest sustainable aerobic pace or effort.” Developing the aerobic system takes time, because we need to build new capillaries to exchange more oxygen, create new mitochondria in your cells to power more respiration, and teach our systems to oxidise more fat.

We can apply this same principle in swimming. To do so we need to swim at a pace that can be considered as our "sweet spot" - a pace that can be estimated from a simple test. We will be doing this test in both swim sessions this week (1st & 3rd Feb). If you intend to swim with the club across February and March you will need to do this test, either in one of these two sessions, or in your own time. Here's how to do it:

1. warm up thoroughly, at least 15 minutes of easy swimming with a few speed spikes to fire up the system

2. using a timer (watch, pool clock etc) time yourself over the fastest 400m (16 lengths of a 25m pool) that you can manage

3. rest and swim easily for 5-8 minutes

4. using a timer (watch, pool clock etc) time yourself over the fastest 200m (8 lengths of a 25m pool) that you can manage

5. send Graeme (graeme@brightontri.org or on WhatsApp) these two times and the date that you performed the test

We will then perform a simple calculation on these two times that gives your Critical Swim Speed (CSS). This is the pace we will ask you to swim at for the main section of each club swim in Feb & March.

Top tip: Your fastest split over 200m & 400m will almost undoubtedly be achieved by starting at a pace that you will initially consider 'easy'. Go off hard & fast and you will blow up halfway.