You may think that swim workouts for endurance simply involve grinding away laps in the pool.

While putting in the time is a fundamental aspect of endurance swimming, several other key factors could help or hinder your results in the water. Building swim endurance becomes more important with increasing race distances.

From a sprint triathlon with a 750-meter swim to a full Ironman swim distance of 3.8 kilometers, there are several areas you may be overlooking when it comes to maintaining a consistently high level of performance in this critical first leg of a race.

So what are some exercises needed for swimming endurance?

The key areas we will need to improve include cardiovascular endurance, muscular endurance, and economy of motion.

This article will provide some examples of endurance swim workouts for beginners, intermediate, and even high-level athletes who may still have room to improve on some of the more intricate aspects of swimming that affect endurance.

1. Swimming and Cardiovascular Endurance

In the aforementioned shorter distance events, and for recreational level athletes, one of the most important elements that influence endurance is the VO2 Max.

Specifically, a triathlete needs to be able to perform at a certain sub-maximal workload, which will be expressed as a percentage of VO2 Max.

Physiologically, this means that improving maximal cardiac output will in turn increase your endurance in the water by enhancing your oxygen uptake, increasing capillary density in the working muscles, and decreasing your heart rate during training at higher intensities.

In practical terms, this simply means you need to do your time in the pool with some long-distance swim workouts and perform with the intensity, and for at least the time or distance that you will be competing at.

For example, a pro triathlete typically spends six days a week in the pool for 4-5 kilometers - that’s 80-100 laps of an Olympic pool - swimming at various intensities. That’s in addition to their cycling and running training!

Cardiovascular Endurance Session

Warm-up: 1-2 laps (50m) each of freestyle, backstroke, breast-stroke

Endurance: 20 laps (beginners) to 80 laps (advanced) @ 70-85% race pace (use RPE 7-8/10)

Cool-down: Same as warm-up + in-pool static stretches

If you don’t have access to a smartwatch that you can use in the water to track your heart rate, simply use a rate of perceived exertion (RPE) from 1-10 to quantify your training efforts in the pool.

Next, we will explore some swim drills for endurance that focus on the working musculature.

2. Swimming and Muscular Endurance

During long-distance swimming, the lactate in your muscles can triple, causing damage to skeletal muscle and creating the burning feeling that hinders your performance at higher intensities. This lactate threshold occurs at different energy outputs during swimming for different athletes.

To improve your ability to perform at a higher intensity on race day, you can take advantage of sprint training, or in laymen’s terms, swimming fast!

This simply involves ensuring that your training program includes sessions in the pool that are focused on performing at higher intensities, and training your body to produce more of the enzymes that transport lactate away from the working muscles.

Muscular Endurance Session

Warm-up: 200m building from 60-80% maximal pace, increase by 10% each lap

Endurance: 4-5 x 100m @ 90-95% maximal pace, with 100m easy pace between

Cool-down: 200m easy pace + in-pool static stretches

Muscular endurance is also improved by dry-land training for swimmers, which you can check out here.

The next section will reveal your new secret weapon to vastly improving your swimming endurance.

Swimming Economy and Endurance

While high cardiovascular and neuromuscular functioning is important to swimming performance, these factors cannot be maintained during the long periods of energy output that an event such as a triathlon requires without a superior movement economy.

Swimming economy - your technique - is an area where triathletes have been shown to need large improvements in comparison to competitive swimmers.

Improving your swimming economy allows you to reduce your energy output without compromising your swimming speed.

It also can reduce the risk of common injuries associated with the repetitive micro-trauma in the shoulders of competitive swimmers and triathletes.

So what factors make up an athlete’s swimming economy?

The mean velocity of swimming can be estimated from the product of stroke rate and stroke length.

For the math fans out there, it looks like this:

V = SR x SL

The main determinant of these that will affect your average speed is stroke length. Skilled swimmers have been shown to have larger stroke lengths, and the decline of velocity during the swim leg of a race is almost completely due to a decrease in stroke length.

3. Drills to Improve Swimming Economy

To improve your swimming technique to stave off fatigue during a race, add some laps into your training program focusing on the following aspects of your swimming stroke:

Neutral Spine - Keep your eyes down, as looking forward increases drag

‘Press the Buoy’ - Actively push your chest down to keep the legs close to the surface

Thoracic Rotation - Work on rotating your shoulders with your stroke to increase range of motion at the shoulder joint

Slower Kicking Pace - Longer distances require a two-kick pace rather than the six-kick pace used in sprint races

Swimming Economy Session

Warm-up: 1-2 laps (50m) each of freestyle, backstroke, breast-stroke

Technique: 200m each focusing on:

  • Head positioning during stroke / breaths
  • Chest down legs up
  • Trunk rotation
  • Match kicking pace to stroke rate

Cool-down: 200m easy pace + in-pool static stretches

Try to focus on improving your technique so that you can swim a lap with the least amount of strokes possible. Covering more distance with each stroke and using less energy will mean that your endurance will greatly improve while performing for longer distances.

Learn more about the basic swimming techniques here.

Breathing Training for Swimming Endurance

Respiratory muscle training aims to strengthen and increase the muscular endurance of the muscles that help you take in and make use of oxygen more efficiently.

For competitive swimmers, this type of training not only improves ventilatory function, chest expansion (which has the added benefit of making you more buoyant in the water), and performance; it also lowers your perceived exertion and shortness of breath more effectively than swimming training alone.

Check out the Airofit, a great tool for this kind of training!

Bonus Tips

Finally, while the factors mentioned in this article will greatly affect your swimming endurance, we want to close with a few extra considerations for your swimming training and competitions.

Don’t forget that the swim leg is only the first stage of a triathlon. Studies have shown that swimming at lower intensities of 80-95% of a time-trial performance significantly improves overall triathlon performance. So make sure you leave something in the tank for the bike and the run!

Also, even the most highly-trained athlete can’t perform without the proper fuel.

Energy stores, hydration and electrolyte balance are all critical to the success of the triathlete, and must be maintained daily as well as during a race.

Finally, don’t forget that in a triathlon, you won’t be in a nice warm pool with your lane. Take into consideration the temperature and turbulence of the water you’ll be racing in, as well as preparing yourself to maintain your orientation while, frankly, getting kicked in the face.

Let us know your favorite swimming training techniques below!