The Benefits of Swimming for Runners

Running is simple. You put on your running shoes, head out of the door and start putting one foot in front of the other. But when you love running, it can be tempting to believe that the best way to become a better runner is simply to run more.

That isn't always the case.

Swimming can be an excellent form of cross-training for runners, allowing you to continue working on your cardiovascular fitness while reducing the repeated impact placed on your muscles, joints and bones. It can provide a useful active recovery session, introduce variety into your training and, in some circumstances, help you maintain fitness when injury prevents you from running normally.

Swimming offers a wide range of physical and mental benefits in its own right, but for runners it can become another valuable tool in a more balanced approach to training.

Is Swimming Good Cross-Training for Runners?

Cross-training simply means incorporating forms of exercise other than your primary sport into your training.

For runners, that could include cycling, strength training, walking or swimming. The objective isn't necessarily to replace running, but to use other activities to complement it.

Swimming is particularly interesting because it provides cardiovascular exercise without the repeated ground impact associated with running. Your heart and lungs are still working, but your body is supported by the water rather than repeatedly absorbing the forces generated every time your foot hits the ground.

That makes swimming particularly useful when you want to continue exercising aerobically without simply adding more running miles.

It is important, however, to remember the principle of specificity. If you want to become a better runner, you still need to run. Swimming cannot reproduce the biomechanics, weight-bearing demands or muscular adaptations of running.

Think of swimming as something that can support your running rather than replace it.

The Benefits of Swimming for Runners

Maintain Cardiovascular Fitness Without the Impact

One of the biggest attractions of swimming for runners is the opportunity to continue developing or maintaining cardiovascular fitness without adding another high-impact training session.

Swimming still requires your heart and lungs to supply working muscles with oxygen. Depending on how you structure the session, it can range from gentle aerobic exercise to a demanding cardiovascular workout.

For a runner already completing several sessions each week, that can provide another opportunity to exercise without automatically increasing running mileage.

This can be particularly useful during periods of heavier training when adding another run might create more fatigue than benefit.

Give Your Legs a Break

Running places repeated stress on the lower body. That stress is an important part of training — your body adapts to the demands placed upon it — but recovery between those stresses matters too.

Swimming removes much of the repetitive impact associated with running.

That doesn't mean your legs aren't working. Kicking still recruits muscles throughout the hips and legs, but the forces involved are very different from repeatedly striking the ground during a run.

For runners who spend a significant amount of time on their feet, getting into the pool can therefore provide an opportunity to remain active while changing the physical demands placed on the body.

Sometimes a useful training session doesn't need to involve another mile.

Support Active Recovery

Not every swimming session needs to be hard.

An easy swim can work well as a form of active recovery following harder running sessions or during a recovery day. Gentle movement keeps the body active without introducing the same mechanical stress as another run.

The key word here is easy.

Turning every visit to the swimming pool into a hard workout defeats the purpose if your objective is recovery. A relaxed swim should leave you feeling refreshed rather than exhausted.

For runners who struggle with the idea of doing nothing on a rest day, this can also provide a useful change of mindset. Recovery isn't wasted training time. It is part of the process that allows you to train consistently.

Swimming can provide runners with a lower-impact way to stay active while supporting recovery between harder training sessions.

Build Whole-Body Strength and Endurance

Running is predominantly a lower-body activity, whereas swimming asks considerably more of the upper body.

Your shoulders, arms, back and core all contribute to moving and stabilising the body through the water, while your legs continue to work through the kick.

Swimming isn't a replacement for dedicated strength training, but regularly spending time in the pool can expose a runner's body to a different pattern of muscular work.

Core control is particularly important. Maintaining an efficient position in the water requires the trunk to stabilise the body while the arms and legs generate movement.

For runners accustomed to spending most of their training time moving forwards on land, swimming provides a very different whole-body challenge.

Maintain Fitness During Injury and the Return to Running

Few things are more frustrating for a runner than being unable to run.

Depending on the nature of the injury, however, being temporarily unable to run doesn't necessarily mean being unable to exercise.

When swimming is appropriate for the particular injury and stage of recovery, the pool may provide a way to maintain cardiovascular fitness while running is reduced or temporarily stopped. Because the body is supported by the water, swimming can sometimes allow aerobic exercise without exposing the injured area to the same repeated impact experienced during running.

It can also have a role as fitness is rebuilt.

After an extended period away from running, the temptation can be to try to regain lost fitness by increasing mileage too quickly. Swimming can provide additional aerobic exercise while running itself is reintroduced progressively.

There can be a psychological benefit too. Injury can make a runner feel as though all of their training has suddenly disappeared. Being able to exercise in another way can restore some routine and provide a sense of progression while the primary goal remains getting back to running.

Swimming won't be appropriate for every injury. Whether and when it should form part of rehabilitation will depend on the injury and the individual, so always follow the advice of your doctor, physiotherapist or other appropriately qualified healthcare professional.

Add Variety to Your Training

There is another benefit that's easy to overlook: swimming is simply different.

Running the same routes and completing similar sessions week after week can become repetitive, particularly during long training blocks.

Going to the pool changes the environment, movement patterns and mental demands of the session.

For some runners, that variety can make a training week feel less monotonous. You can still work towards your running goals while occasionally stepping away from running itself.

And sometimes enjoying your training a little more is reason enough.

Swimming vs Running: What's Different?

For all its advantages, swimming isn't running.

Running is a weight-bearing activity. Your muscles, tendons and bones adapt to repeatedly supporting and propelling your body against gravity. Your nervous system also becomes more efficient at coordinating the movement patterns required to run.

Swimming places very different demands on the body.

The support provided by the water is one of the reasons swimming can be so useful for cross-training and recovery, but it is also why swimming cannot completely reproduce the adaptations created by running.

A strong swimmer isn't automatically a strong runner, just as a strong runner isn't automatically a strong swimmer.

If your goal is a faster 5K, half marathon or marathon, your running sessions should remain the foundation of your training. Swimming can sit alongside those sessions, providing additional aerobic exercise, recovery or variety without simply accumulating more running mileage.

How Runners Can Add Swimming to Their Training

There isn't one swimming session that will suit every runner.

How you use the pool should depend on what you're trying to achieve.

If recovery is the priority, keep the effort relaxed and concentrate on comfortable, controlled swimming.

If you're replacing an aerobic running session, you might swim continuously at a steady effort or use longer repetitions separated by short recovery periods.

If you're using swimming because your normal running volume has temporarily been reduced, the session can provide cardiovascular work while limiting additional impact.

And if you're simply looking for variety, there is nothing wrong with swimming because you enjoy it.

The important thing is to consider swimming as part of your overall training load. A hard swimming session is still a hard training session, even if you haven't run a single mile.

Sometimes Running Less Can Help You Run More

Runners naturally think in miles.

Weekly mileage, long-run distance, race distance and pace are all familiar ways of measuring progress. It can therefore be easy to assume that every improvement has to come from running more.

But successful training isn't simply about accumulating as many miles as possible. It's about creating enough stimulus to improve while recognising why recovery is just as important as training.

Swimming can help provide that balance.

It won't replace the specificity of running, and it won't magically make you a faster runner. What it can offer is cardiovascular exercise without another impact-heavy session, an alternative form of active recovery, a whole-body workout and, when appropriate, a way of maintaining fitness during periods when running isn't possible.

Ultimately, swimming doesn't have to compete with running.

For the runner who uses it at the right time and for the right reason, it can help support the thing they really want to do:

keep running.