How to control your swim to build endurance

Hard work is critical for improving swim performance, but you also want to be able to finish races in control. Andrew Sheaff has the solutions to make you a more 'sustainable' swimmer

Kenneth Vandendriessche of Belgium competes during the swim portion of the IRONMAN World Championships on October 08, 2022 in Kailua Kona, Hawaii.

As any endurance athlete knows, hard work is critical for improving performance. Most know firsthand that the harder and longer you work, the faster you go. However, there are certain circumstances where taking a step back makes a lot of sense. 


When it comes to the swim leg, many triathletes are faced with a unique challenge. More so than trying to improve your endurance to go faster, for many, the focus is on improving your endurance so you can simply finish the race!

While you can simply slow down on the bike, or walk on the run, some triathletes don’t have the option to go ‘easier’ in the swim, as it’s a challenge just to keep moving.

So if you’re looking to improve your ability to finish swim legs reliably and comfortably, you many need to take a very different approach as compared to how you train on land.

If swimming at any speed is difficult, it’s going to be nearly impossible to finish races that require you to swim for an extended period of time. This article is about how to shift your perspective on swim training so that you can finish races in control.

With all of the suggestions below, the commonality is to stay within yourself. If you’re going to endure for the race distance, you have to be able to swim in a manner that is sustainable. If you’re pushing it too much, you’re not going to learn how to move through the water sustainably, and that’s going to cause problems on race day.

Go easy

Focus on swimming as easily as possible. The best way to improve the duration you can swim is to learn to dial down the effort as much as possible. Once you can swim easy, then aim for duration. Don’t worry about speed as the main goal is sustainability.

Focus on duration

When it comes to progression, focus on swimming for longer distances and longer durations without a break. As the ultimate goal is to be able to be comfortable over race distances, work towards that end rather than trying to swim harder and faster. While you may only improve 50m at a time, longer swimming is progress!

Start slow

While it’s tempting to get caught up in how fast you’re swimming in training, and gauging your progress based upon how fast you can swim over short distances, resist the temptation. Remember that until you can complete the race distances comfortably, it doesn’t matter how fast you swim.

By starting slow, you’re giving yourself the best chance to build sustainability. Add the speed once you can handle the distance.

Do less

Stop your workouts before you really start to struggle. You want to practise swimming in control and comfortably. While it’s necessary to experience some fatigue while you train, you want to always feel like you’re in control.

Keep the repetition distances a little short, the rest periods a little longer, and the total volume a little lower so you can practise control.

If you’re looking to build the endurance to finish a longer open-water swim, give this approach a shot.

The key idea is sustainability – am I practising swimming in a way that’s sustainable? While shorter, faster work still has its place, a big focus should be on sustainability rather than speed. Then, once you’re confident in your ability to reliably finish races, feel free to start cranking up the intensity!


Top image credit: Katelyn Mulcahy/Getty Images for Ironman