One of the best cross-training exercises for runners is pool running. It’s zero impact and has an extremely low risk of injury – making it a perfect supplemental form of training for a healthy runner and one of the best alternative exercises for injured runners.

I spent a full two weeks in the pool doing pool running workouts during my senior year of college when I was injured. Never before had I worked out harder during an injury.

But I did: I often pool ran twice per day and did hard workouts almost every day. With zero impact, you can increase your effort substantially in the pool without getting hurt.

After those two weeks, I came out of the pool and ran significant personal bests in the indoor 3,000m and outdoor 5,000m. I was officially a pool running convert, realizing that it’s power to maintain running-specific fitness is unmatched with other forms of exercise.

Pool running is my favorite form of cross-training for runners because it’s highly specific to running; it closely mimics your running form while using most of the same muscles. You will be able to maintain your fitness even if you’re not doing any running on land. Keep in mind that you pool run in the deep end. You are not supposed to touch the pool floor.

While cycling outside can be a great form of cross-training or injury rehabilitation, hilly terrain can force you to work harder than you’d like. Downhills can also decrease your effort because you don’t need to pedal to maintain your speed. I own a road bike and love to ride, but if you don’t have access to a pool then a fitness bike can help you stay in great shape. Indoor spinning allows you to control how hard you work – plus, there’s no risk of crashing!

The ABC’s of Pool Running Form

If you’re hurt, you can immediately transition all of your training into the pool. In fact, you can actually spend more time pool running because you virtually can’t get hurt.

Once you’re in the pool, the most important part of your workout is maintaining proper form. Just like running on land, you need to keep your back straight (no slouching!) and maintain a quick turnover of at least 180 strides per minute. Pump your arms the same way as well, maintaining about a 90 degree angle at your elbow.

Where most people fail at pool running is with a low cadence. Trying to take slower strides is a mistake and will make your legs overextend in the water. The biggest risk for injury lies in overextending your legs and risking a slight hamstring strain.

Instead, drive your knee up and then drive your foot down. Your stride will slightly mimic that of a cyclist and may be more up and down than usual. That’s fine and completely normal.

Some over-enthusiastic runners think that by not using a water belt (or Aquajogger) that they’re getting a better workout. While it’s true that you’ll have to work harder, it’s almost certain that your form is going to suffer. Instead, get a pool running belt and use it to maintain your form.

Because of the buoyancy of the water and the Aquajogger, you’ll need to be extra diligent in maintaining a quick turnover. One of the best ways to do this is to run workouts in the pool.

Pool Running Workouts

Being in the pool fools you into thinking you’re working hard when in reality you’re probably not. With no wind resistance or impact, plus the natural effect of the water on your body, your heart rate is going to be artificially lower than usual.

It’s important to keep your heart rate up or else you’re not maintaining much fitness. To do this, you implement a fartlek style workout to almost all of your pool running sessions.

These workouts are all based on effort. When I was in the pool, I used three effort levels when designing my workouts: sprint (100% effort), hard (90% effort) and tempo (80%). Sprint efforts lasted 15 – 30 seconds while hard efforts lasted 2 – 5 minutes. Tempo efforts could last 5 – 10 minutes.

Like I mentioned before, pool running workouts have to be hard. If your form is correct, you virtually can’t get hurt. With that in mind, your workouts may seem intimidating. They’ll likely be longer with more fast running than the workouts you’ve done on land!

Below are three examples of pool running workouts that are of varying intensities. As you’ll see, the shorter session is focused on speed development, while the longer workout is focused on developing your aerobic capacity.

Reminder: a dynamic warm-up is still recommended before these workouts.

Workout 1: 45 minutes

10 minutes easy pool running. 10×1’ at hard effort with 1’ active recovery. 10×30” at sprint effort with 30” active recovery. 10 minutes easy warm-down.

Workout 2: 60 minutes

15 minutes easy pool running. Pyramid workout: 1’, 2’, 3’, 4’, 5’, 4’ 3’, 2’, 1’ at hard effort except the 5’ session which is at tempo effort. Each interval has 1’ of active recovery. 12’ easy warm-down.

Workout 3: 90 minutes

15 minutes easy pool running. 5×5’ at tempo effort with 1’ active recovery. 4×3’ at hard effort with 1’ active recovery. 6×30” at sprint effort with 1’ active recovery. 21’ easy warm-down.

These three workouts are just examples of what you can do in the pool to maintain your fitness while injured (or give it a boost if you’re healthy). Your options are only limited by your imagination.

I have sprinted every other side of the pool while jogging the other sides. I’ve done diagonals across the pool at sprint effort while doing easy running on the straight sides. My point is that you can be creative – as long as you are mixing hard running into your pool workouts, you can be confident that your heart rate is high enough to mimic land running.

Your cheat sheet to successful pool running:

Form comes first: back tall, fast cadence of 175+, and don’t overextend your legs. Use an Aquajogger. Implement fast running in almost all of your workouts to ensure your heart rate is high.

If you start pool running for several days doing high-intensity workouts, you’ll notice something odd: you will be able to eat much more than usual! Even though your workouts are of a similar length to before you were in the pool, the thermal load of the water will spike your metabolism.

Since water is a much better heat conductor, it will force your body to generate more heat to stay warm (and therefore burn more calories). As detailed in Tim Ferriss’ book The Four Hour Body, this is how Michael Phelps is able to eat over 7,000 calories per day. It’s a combination of the time spent in the pool and the effect of the water.

My last recommendation for making pool running a part of your training is to get a friend to go with you. Unlike running outside or cycling, it’s incredibly boring. You’ll be working really hard but moving slowly. It can be mind-numbing so enlist the help of another runner to join you.

How have you used pool running to gain fitness or maintain it while injured? Let us know of any other pool running tips in the comments!

PS. [Yes, you can do a PS in a blog post] We have a lot more helpful tips to improve your running in our free beginner’s running course.

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