One of my key test swims is a straight through 3.8k TT done in the wetsuit in the pool. It’s a really tough session and works on a whole lot of areas. Pacing, mental focus, strength endurance and of course swim fitness.

Why would you ever try to swim 3.8k in a pool in a wetsuit? There’s a couple of reasons we incorporate it.

  • To practice correct fitting and swimming in a wetsuit for the full Ironman distance

If like me you live somewhere that swimming in the open water year round isn’t too appealing and you’ve got a race coming up at a time of year that long open water swims aren’t practical then it’s often the only way to practice swimming in a wetsuit without freezing. Getting your wetsuit on correctly is absolutely crucial. If you don’t put it on correctly it could easily cost 5-6 minutes in an Ironman swim as you fatigue faster due to restriction in the shoulders.

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  • To learn the importance of pacing

Sessions should where possible have an element of learning as well as the physical training component so combining the wetsuit with a long endurance session gives the session a number of benefits. Learning how fast you can start without blowing up half way through is one of the most important lessons not just for the swim but for all three legs of Ironman racing and learning how to pace correctly in training is a critical elements to having a good race day.

  • For the strength endurance and fitness benefits of a long continuous swim.

Brett Sutton the most successful triathlon and Ironman coach in the history of the sport is a big fan of swimming the full distance in training as often as possible. Swimming 3.8k regularly is the best way to get better at swimming 3.8k.

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  • Because when its done correctly this is the most effective training zone for Ironman so there are huge fitness benefits

One of the most common mistakes we see is people training too hard. While slowing down in training can seem very counter-intuitive it is one of the keys to success for endurance training. This session forces you to stay firmly in that aerobic zone that has such a huge impact on overall fitness.

  • To work on and develop mental strength and focus

This can be a very difficult session to get your head around and can be really hard to do especially if you’ve gone off too fast. Even when it’s paced correctly the last 1000m hurts and it’s great mental training. On race day Ironman will force you to spend a lot of time alone in your own head and this is good practice for that.

Of course indoor pools can often be quite warm so we only do this in the National Aquatuic Centre in Dublin or if we are away with access to an outdoor pool. Most heated indoor pools are just too hot to last (in my case) a full hour so if you’re going to have a go at it make sure you don’t cook yourself like a boil in the bag rice.

What’s your favourite killer session? Feel free to post in the comments below.


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From smoker to back of the pack triathlete to the Ironman World Championships.

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