The Injured Runner’s Guide to Pool Running

A stress fracture, serious soft tissue injury, or other injuries can prevent you from running for weeks. Many runners worry about losing hard-earned fitness during injury. For most runners, the hardest part about an injury is the lack of exercise. A good cross-training option, such as pool running, will maintain your fitness and give you a mental boost during injury.

Pool running (sometimes called deep water running) is a non-impact modality of cross-training. The name describes it completely: you get into the deep end of a pool and, with buoyancy provided from a flotation belt, run through the deep end of the pool. It sounds ridiculous and looks ridiculous, but it will maintain your running fitness while injured.

Once my broken metatarsal healed enough that displacement was no longer a concern, I started to pool run. I found pool running to be more enjoyable and mentally satisfying than the stationary bike and easier to master than swimming.

Pool Running Benefits

While not a perfect substitute for running, pool running is one of the best cross-training exercises you can do while injured. Pool running allows you to cross-train in a manner specific to running but without any impact. According to a 2003 study in the Journal of Sports Sciences, pool running will maintain aerobic performance for up to six weeks in trained endurance athletes (ie runners). This means that even during a stress fracture or serious strain, you can maintain your fitness.

Pool running is not just reserved for those injured runners. For pregnant runners, pool running allows them to stay fit without the forces of gravity causing discomfort. Runners who want to boost their fitness while avoiding injury can pool run once or twice per week in addition to running.

Other notable benefits of pool running include:

• Neuromuscular fitness: The motion patterns of pool running are highly specific to running. Your arm swing remains nearly identical to that of overground running. The knee drive and cadence, when done with proper form, mimic your running stride. This will help your muscles and nerves remember how to run during a long layoff from the roads.
• No comparison point: With swimming and cycling, you can compare your lap pace or speed with others. It can be discouraging to feel like you are utterly deconditioned because your swim speed is slow. There’s no comparison in with pool running, whether to others on Strava or to your paces on the road. The entire workout is measured in time and effort.
• Minimal learning curve: Pool running is relatively intuitive for runners. Swimming often requires learning a new skill. While cycling is relatively easy to grasp, you might not want to deal with learning how to set up a bike in spin class.
• Movement: Mentally speaking, one of the hardest aspects of injury can be the lack of movement. Even the spin bike or elliptical can feel dull since you remain station. Pool running allows you to actually move forward, even if just back and forth along half the length of a lap pool.

It is vital to note that pool running is not a perfect substitute for running. A 2018 study published in the Journal of Strength and Conditioning Research found that muscle activity, maximal oxygen uptake, and maximal heart rate are all lower during pool running compared to treadmill running. This doesn’t mean pool running won’t maintain your fitness – it will – but it simply means that you will require a transition period back to your normal volume and intensity of road running after your injury. Don’t plan to pool run for six or more weeks and then immediately run a marathon PR. Your musculoskeletal system will also need time to re-adapt if you have been unable to run for more than three weeks.

Pool Running Form

Proper pool running form is similar to optimal overground running form. You want to maintain an upright posture and straight back (think of McMillan’s valuable cue: run tall). With the belt, you will be submerged up to your shoulders or neck, so you maintain a 90-degree bend at your elbow and pump your arms through the resistance of water. Be mindful not to start doggy paddling with your hands.

For your legs, you want to maintain a quick cadence. Drive your knee up and then drive your foot down with quick turnover. Quick cadence will help keep your heart rate high. In my experience, this felt halfway between a running stride and a cycling stride, but this article on Strength Running reassured me that it’s okay to feel a bit like you are cycling.

What You Need to Pool Run

As the name implies, pool running does require some special equipment:

• Access to a lap pool: Pool running must be done in a pool deep enough that your feet do not touch the bottom. A leisure pool may not be deep enough. In your typical gym lap pool, you will only pool run on the deep end. Shallow pool running is not optimal and is simply not an option at all if your injury restrictions include no weight-bearing.
• AquaJogger/flotation belt: A pool running belt will help you maintain good form throughout. You can pool run without a belt, but you might sacrifice form or become too inefficient to put in the appropriate volume. Wear the pool running belt just below your rib cage, with the floater on the small of your back. Many gyms will have AquaJoggers with their swim equipment. I was able to use the ones at my local Y (surprise, there’s not much competition for them, even during busy hours). If not, you can purchase one for a relatively inexpensive cost on Amazon. 
• Swimsuit: Any athletic swimsuit will do! You do not need goggles or a swim cap. 
• A good sense of humor: You will look and feel ridiculous. You may garner some curious, confused, or pitying looks from other pool-goers or even the lifeguards. 
• Optional: Fitness tracker: I wore my Garmin 230 on all pool workouts to track time and program intervals. Many fitness trackers are waterproof up to 50m, but you want to confirm this before you take your expensive watch into the pool. Most gyms will have a large clock on the pool wall, so a watch isn’t necessary.

Pool Running Workouts

Pool running has no impact, which means you recover sooner from a pool run than a road or treadmill run. You can do intervals almost every time you pool run due to the quick recovery. Intervals get your heart rate up enough to give you a good workout and helps pass time when treading water in the deep end.

Essentially, any time-based interval workout you do on land can be done in the pool. Since your heart rate recovers more quickly in the water, you want to shorten the recovery intervals to 30 seconds to 1 minute when doing an interval workout.

In terms of effort, use your breathing and perceived exertion to gauge. For intervals 30 seconds to 3 minutes in duration, “run” at a hard effort that labors your breathing. Complete intervals last 5 or more minutes at a tempo effort (comfortably hard).

As with any road workout, always warm up and cool down with easy pool running. The warm-up provides an opportunity to practice your form (along with all of the other benefits of a warm-up).

These pool running workouts are variations of some of my favorite road fartleks. You can reduce the number of repetitions or length of warm-up or cool down for a shorter workout or increase the length of warm-up and cool down for a longer workout.

Fartlek 1: 50 minutes
10 minutes easy pool running
4 x (1 min hard, 1 min easy, 1 min hard, 1 min easy, 2 min hard, 1 min easy)
10 minutes easy pool running

Fartlek 2: 50 minutes
15 minutes easy pool running
5 x 3 minutes hard, 1 min easy
5 x 30 seconds hard, 30 seconds easy
15 minutes easy pool running

Tempo: 60 minutes
15 minutes easy pool running
5 x 5 minutes at tempo with 1 minute easy in between
15 minutes easy pool running

Try any fartlek workout you enjoy and have fun! 

If you are injured – or wanting to prevent injury – pool running is a great workout. With the right attitude, good form, and an challenging workout, it can even be an enjoyable cross-training option.

For more cross-training workouts, read the following posts:
A Runner’s Guide to the Elliptical
Swimming Workouts for Injured Runners

Linking up with Coaches’ Corner and Wild Workout Wednesday! 

Have you ever tried pool running?
How have you cross-trained through injury?