a man is swimming in a open air pool with hand paddles for training

Building Endurance for a Triathlon Swim

My name is Scott Ludford and I am a triathlete on the ZONE3 USA Pro Team.

While the swim is the shortest part of the triathlon, knowing how to build your endurance for a triathlon swim should not be overlooked. Being able to have a strong swim doesn’t only make you more competitive in the water- it can also set you up to have more energy for your bike and run. Having a strong swim on race day can require a lot of preparation, so how should you train your swim for maximum endurance? Let’s dive in. 

Scott Ludford is looking at the camera, his image overlaid onto a pink and blue gradient background

Longer Sessions, Shorter Reps

Something I often see with new triathletes is that they approach swim training as reaching a distance goal


For example, if you were training for an Olympic distance triathlon that has a 1500m swim, many people would structure their swim workouts to swim 1500m all in one go.


While this does get you used to covering the distance, it is important to focus on speed, technique, and building your aerobic system to cover longer distances. Training this way will ensure you build endurance for your triathlon swim event.


One way to do this, is to incorporate shorter repetitions over the course of a longer workout. Using the previous example of training for a 1500m swim, one possibility for a workout could look like this:

Warm up: (800m)

  • 300 swim, 100 kick, 100 pull

  • 3x 100 as 50 drill, 50 swim.

Main Set: (1200m)

  • 4x 200 at race pace resting 20 seconds in between.

  • 4x 100 at threshold pace resting 30 seconds in between.

Cool Down: (100-200m)

This 2200m set incorporates a warm up with some drill / technique work and 1200m working at or above race pace but gives shorter intervals to refocus on dialling in technique before each rep. 


Additionally, there is some speed work to get used to a higher intensity and train your body to have ‘gears’ to shift through in the water so that your muscles aren’t shocked on race day. 

a man is swimming in a pool and the photo is shot from under the water showing his front crawl stroke. the man is wearing a wetsuit.

Fuelling to Build Endurance For A Triathlon Swim

As you build your swim sets to a higher volume, just like in the other disciplines, it is important to fuel during your sessions.


While it’s true that (most of the time) on race day there are no opportunities to fuel during the swim, practicing nutrition in training can allow you to swim for longer, recover quicker, prevent cramping during sets, and feel ready to take on other sessions throughout the day.


When choosing what to fuel with, it’s good to use something with carbohydrates (~30g-60g) and occasionally sodium (~300-1000mg). 

Consistency in Your Training

How does consistency play a part in building endurance for your triathlon swim?


Structuring your training week to incorporate a few regular swims will help develop your swim endurance and speed.


Think of swimming as being ‘feel’ dependent; often swimming more regularly will help you maintain your feeling or technique in the water. When adding different swims to your week, it’s important to be intentional - giving each swim a purpose that lines up with previous swims and other training from that week. This means including a swim that targets speed, a swim that targets your race pace, and a swim that targets technique and recovery. 

Endurance for Race Day

Now that the work has been put in from all of your training, it’s time for race day.


Believe it or not, there are also ways that we can improve our swim endurance on race day.


Hydrate and carb up in the days leading up to, and just prior to the swim start. 


Start out strong, but find a steady pace to settle into so that you don’t burn out too quickly.


Work with other swimmers! There are drafting benefits in the water when you swim behind or to the side of other swimmers.


Practice good sighting. After spotting the buoy, orient yourself toward it and swim a few strokes before sighting again; it’s not necessary to sight every stroke in order to swim straight and it will use a lot of extra energy.

Scott Ludford - ZONE3 Pro Team USA Ambassador