Sub-1hr swim session: Pacing changes

Increase speed, lung capacity and acclimatisation for race day


Master this pool fartlek from the Rebekah Keat and Siri Lindley armoury to increase your speed, lung capacity and acclimatisation for race day


This is a great Sunday session after a hard bike or run on the Saturday. You don’t need to do this as a main workout but you still get great benefits.

For this workout you’ll need: swimsuit/trunks, hat, goggles, snorkel, pull buoy, band, snorkel and paddles.

Pacing changes


600m pull buoy, band, snorkel as: 200m easy, 200m [2 x 25m fast/75m easy], 200m build.

Main session

500m [10 x 50m band only, focus on high stroke rate]; 2 x [1,000m fartlek swum as 25m fast/75m easy/50m fast/50m easy/25m fast/75m easy/100m fast/100m easy].


500m easy swim with paddle, hypoxic and bilateral [breathe every 3 strokes for 100m, every 5 for 100m, every 7 for 100m, every 5 for 100m, every 3 for 100m]. 100-500m, easy swim kick.

Performance benefits

The snorkel is great for improving your head position and keeping it still. Watch your hand entry and make sure it’s entering the water right out in front of you.

The band-only workouts force a fast stroke rate and a focus on turnover to keep your legs afloat. Fartleks are good for race simulation and practising the changes of pace needed to stay with faster swimmers.

Mental benefits

This set has plenty of race simulation benefits, getting you mentally ready for race day. Hypoxic breathing is great for controlling your breathing and also great for race simulation, such as being pushed under the water at the start and training your mind to relax while there’s an oxygen deficit.

Physiological benefits

The changes of pace in the fartlek session will improve your aerobic capacity, with the hypoxic cool-down improving your breathing capacity.

Adapt for Ironman

You could add 500m to the fartlek section and make it 1,500m if you’re doing 70.3. For Ironman you could add 1,000m to the fartlek.

(Photos: / Jonny Gawler)


Head to our Training section for lots more performance advice and workouts