70.3 swim advice and sessions from Lucy Charles-Barclay

Ironman 70.3 world champion and former top open water swimmer Lucy Charles passes on her top tips and swim sessions for mastering the middle-distance swim

Lucy Charles showing us how it's done. Credit: James Mitchell

 1. Pace your 70.3 race

If you’re stepping up from Olympic-distance racing to Ironman 70.3, then the swim distance increase from 1.5km to 1.9km swim shouldn’t seem too daunting. However, the distances that follow on the bike and run might mean you want to adjust your swim pacing slightly. My key piece of advice for the 1.9km swim on race day is to get off to a strong start, find your space and then settle into your own rhythm. Aim for 2-3secs per 100m slower than your usual Olympic-distance event pacing.

Advertisement MPU article

2. Adding 70.3 swim speed

Adding in high-intensity interval swim sessions to your programme, including repetitions of 200s, 100s and 50s, will help massively with increasing your middle-distance swim speed. Aim to do at least two swims a week where you’re working hard over the 1.9km. Break the distance down into shorter repeats – your target times should be at race pace or faster with short rest intervals of 10-20secs.

3. Pre-race nutrition

For breakfast before a middle-distance race, I have a bowl of porridge and two slices of white toast with peanut butter, and a black coffee. I recommend that you aim to drink at least 500ml of electrolyte mix before the start so you’re well hydrated before the gun goes.

Build 70.3 speed swim set

I perform this set in the build-up to a 70.3 race.


400m steady + 30secs rest

2 x 200m build + 20secs rest

2 x 100m @ 1.9km target race pace + 30secs rest

4 x 50m building speed + 20secs rest

100m easy swim

Main set

30 x 50m @ faster than 1.9km race pace + 30secs rest


200m easy swim.

70.3 pool set

Benefits? A mixture of race-pace threshold efforts mixed with some strength work; short recovery times help to boost anaerobic capabilities

How close to race day? The final 4-6wks

Distance: 2,600m

Kit: pull buoy, paddles, stopwatch

Nutrition: eat a light meal up to 2hrs prior to swim, 500ml energy drink during session and have a post-session
protein snack ready


200m to include variety of strokes

Main set 

2 x 300m @ PE 8* off 20secs RI**

250m + paddles @ PE 6

4 x 150m @ PE 8-9 off 15secs RI

250m + pull buoy @ PE 6

6 x 100m @ PE 9 off 10secs RI

100m to include variety of strokes


Beginner: increase recovery time by extra 5secs

Advanced: complete the 6 x 100m with paddles

 70.3 open-water swim set

Benefits? Preparing for the physicality and techniques needed for confident race swims. This session is best done with other swimmers if possible

How close to race day? The final 4wks Distance 2.5km Location Open water
Kit Wetsuit, stopwatch

Nutrition: eat light meal 2hrs prior and have a post-session protein snack ready


300m @ PE 5-8

Main set 

500m focus on sighting and turning at marker buoys

3 x 100m practise race starts

500m focus on drafting other swimmers

3 x 100m practise race starts

500m @ race pace


100m @  PE 6


Beginner: practise drafting and being comfortable swimming around others

Advanced: include some hypoxic breathing intervals during race starts

*See PE chart on p85; **RI = rest interval

The final word

Train harder than you race and then you’ll deal with it successfully in the race. When it comes to racing, stay in the moment and don’t try new things just because someone said you might be faster with it.
DANIELA RYF, 2017 Ironman 70.3 World Champion

Advertisement MPU article