Sub-1hr session: open-water simulator

Boost your top-end speed in the open water


Emma-Kate Lidbury prescribes a 60min pool sesh that will boost top-end swim speed and improve pacing in the open water…


Equipment needed: Swimsuit, hat, goggles, pace clock or stopwatch, training partners, pool with deep end where you can dive in.

How to fit it in: To really get the most from this session, try to hit it relatively fresh. Avoid doing it the day after a long or hard run workout, and try to schedule it for when you won’t be doing any other intense workouts. Prepare yourself for the fact your lats/upper body might be sore after the deck-ups, but it gets easier!



10mins easy swim, mixed strokes, then 12 x 50m front crawl, progress 1-4 three times through (1st easy, 2nd moderate, 3rd moderate-fast, 4th fast), 10-15secs rest between.

Main session

Begin on poolside at the deep end. Dive in. Swim 200m as 50m fast, 150m at 80%. 

As soon as finished, ‘deck-up’ (climb out of pool onto side). Rest 30-45secs. Repeat six times. Include two sightings within each length. 


200-300m easy swim, including backstroke and breaststroke.

Main benefits

Performance benefits

Over time, you’ll notice that you have greater control over your pacing and can hit top speed and then switch down a gear far more easily. This will translate to improved speed and efficiency on race day and will give you huge confidence. Your aerobic endurance and anaerobic fitness will vastly improve, as will your swim splits. Working on sighting in the pool will help you in open water, too.

Mental benefits

Learning to hit top speed and then settle back isn’t easy. It’ll often take most of the second 50m – if not more – to feel like you have your pace under control, but this is great race-day practice. When you start feeling fatigued, concentrate on your stroke and stay process-orientated. Practise staying positive and ‘in the moment’. 

It will prepare you greatly for racing. 

Physiological benefits

This session is a race-day simulation, with the initial 50m to be swum at the speed you’d do the first 50m in a race. This helps train your body in hitting top speed right from the off. By then settling into swimming at 80%, you’re forcing your body to get used to the change of pace needed to execute a smart swim.

Finishing with a deck-up after each repeat is not only a great strength exercise for your upper body, but it will also spike your heart rate. This is what you need to grow accustomed to when exiting the water on race day.

Adapt for Ironman

Within the main set, increase the distance of the six swims to 400m and break it up as follows: 50m fast, 150m at 80%, deck-up, dive back in, 50m fast, 150m at 80%, deck-up. Rest 30-45secs. Repeat x 6.