Sub-1hr session: Threshold beater

How to raise your swim threshold – fast


Want to increase your speed and fitness in the water, but strapped for time? Here’s a sub-1hr workout that will help…

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For this session you will need a swimsuit or trunks, hat, goggles, water bottle, towel, and a watch or pace clock. 

To get the most out of this session, you need to be relatively fresh, so don’t attempt it after a long run or hard bike. 

Try to schedule it on a day when you won’t be doing any other intense workouts. An easy run or bike the same day should be fine.

The session


10min steady swim, followed by 8 x 50m as 2 x [25m fast/25m easy; 25m easy/25m fast; 50m easy; 50m fast]. 

Give yourself 10secs of rest after each 50m.

Main session

10 x 200m (or 175m/150m/125m, depending on swim speed/ability to make these times). 

Begin on a 3:20min send-off time, but each 200m (or 175m/150m/125m) sees 5secs knocked off that time so the 10th swim is done on a 2:30min send-off. 


5min easy swim, mixed strokes. 

Main benefits

Performance benefits

This session is ideal for getting your body familiar with working around threshold and above. 

If done consistently, you will notice that the benefits translate to your aerobic and anaerobic fitness with improved ability to swim for extended periods at race pace. 

This should mean one thing on race day: faster swim splits!

Mental benefits

This session will push you to your limits – and that’s the idea. It teaches your body and mind about consistently working at your maximum. 

It’s great practice for racing when you need to have tested yourself in training to know how to deal with the pain and effort of all-out swimming. 

Physiological benefits

Be warned – this workout will hurt!

Although in the early repeats the send-off times seem easy, if you swim too hard too soon you’ll pay for it in the latter stages of this set. 

The early repeats are all about steady aerobic swimming. 

The final repeats will see you working at your threshold and above. If done correctly, it yields great aerobic and anaerobic fitness gains, as well as speed and efficiency. 

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From the seventh or eighth repeat onwards, you’ll likely be working at or near threshold and will then have to push it up a gear again.