Aqua jogging: how to run in deep water, and what it kept in runners' fitness

Aqua jogging, also called deep-water running, is running in the water where your feet don't touch the bottom. A 2003 review describes it as done in the deep end of a swimming pool, normally with the aid of a flotation vest.¹ There's no ground to push off, so it trains the running motion against the water instead.

This page covers how to do it, the belt, what lab tests measured against running on land, what weeks of it did in training studies, and a session to start with. It's in water over your head, so it's for people who are comfortable in deep water: the American Red Cross describes water competency as being able to enter the water, get a breath, stay afloat, change position, swim a distance, then get out of the water safely.² If that isn't you yet, the standing-depth version is the pool workout.

How to aqua jog: the technique

Practical, not from a trial:

• Get deep enough that your feet can't touch the bottom, and wear the belt snug around your waist.
• Stay tall, head and shoulders out of the water, with a slight lean forward, as if you were running uphill.
• Run the same motion as on land: drive the knee up, push the foot down and back under you, and let the arms swing from the shoulder as they would on a run.
• Expect to move slowly or not at all. Staying in one spot is fine; the work is pushing the water, not covering distance.

There are two common styles, and a muscle study compared them. In 11 healthy adults, average age 24, the deep abdominal muscle (transversus abdominis) was significantly more active in both deep-water styles, high-knee and cross-country, than standing in water, and more active with high knees. During high-knee running in deep water it was comparable to walking on a treadmill.³ That's muscle activity, not a strength result.

Do you need an aqua jogging belt?

The lab studies on this page used one: a flotation vest or device in the review, in the treadmill comparison of men and women, and in the runners' lab study.^1,4,5 Practical: it holds you upright so the effort goes into the running motion instead of staying afloat, which is why it's the usual way to start. Without one, part of the work goes into treading water. Any flotation belt made for water running does the job; this page doesn't name a brand.

Aqua jogging vs running on land: what the lab measured

Peak numbers come out lower in the water. Four studies tested trained people, most of them runners, to their maximum in deep water and on a treadmill:

Lower peaks don't make it a weak workout. Butts 1991 put the gap at about the size found between treadmill running and cycling, and the 2003 review judges deep-water running an adequate stimulus for cardiovascular training.^4,1 The Compendium of Physical Activities rates water running at 6.5 METs at 30 steps a minute, up to 9.8 at 60 steps a minute, the same 9.8 it gives vigorous water jogging.⁸

Heart rate and effort in deep water

Below the maximum, heart rate runs lower too. In Svedenhag 1992, at the same oxygen uptake, heart rate was 8 to 11 beats a minute lower running in water than on the treadmill, at every intensity, while at the submaximal loads perceived exertion for legs and breathing was higher in the water.⁵ Butts 1991 advises caution if training intensity is set from heart rates measured on land.⁴ Practical: go by effort. Easy is a pace where you could talk; hard is a few words at a time. If you train by heart rate, expect the water number to read lower than the land number for the same work.

Does aqua jogging keep running fitness? The training studies

• 6 weeks, trained male runners. Sixteen runners were matched into a treadmill group and a water-running group, each training 5 days a week, alternating 30 minutes at 90 to 100% of VO2 max with 60 minutes at 70 to 75%. Neither group's treadmill VO2 max, ventilatory threshold or running economy changed significantly, and the groups didn't differ.⁹
• 6 weeks, three ways. Thirty-two trained adults aged 18 to 26 were assigned to water running, cycling or running at similar frequency, duration and intensity. All three groups' VO2 max fell slightly but significantly, 2-mile run time didn't change, and the mode made no difference.¹⁰
• 4 weeks, water only. Eleven well-trained competitive runners replaced all their running with deep-water running, 5 to 6 days a week, after instruction and practice sessions. Their 5 km treadmill time didn't change significantly (about 1,143 seconds before, 1,150 after), nor did their VO2 max.¹¹
• 8 weeks, inactive older women. Seventy women aged 60 or over were randomised to deep-water intervals or the same intervals on a treadmill, twice a week. The two groups' VO2 max improvement was similar, and adherence was above 90%.¹²
• 28 weeks, older adults. Thirty-six older adults trained twice a week with continuous or interval deep-water running; both groups improved the up-and-go test, strength of the arms and legs in repetitions, leg flexibility and the 6-minute walk.¹³

Two reviews sum it up. The 2003 review: aerobic performance is maintained with deep-water running for up to 6 weeks in trained endurance athletes, sedentary people improve their maximal oxygen uptake more than athletes do, and gains show most in tests done in the water.¹ A 2022 systematic review of 11 trials (287 people, healthy and clinical groups) found deep-water running comparable to land-based training for cardiorespiratory fitness, without pooling the results because the trials differed too much.¹⁴ In short: in trained runners it held running fitness for 4 to 6 weeks about as well as running did, rather than adding to it, and in inactive older women it built fitness about as well as the same intervals on a treadmill.

An aqua jogging workout

For beginners (practical): 5 minutes easy, then 6 rounds of 1 minute hard and 1 minute easy, then 5 minutes easy, about 22 minutes in all. Add rounds before you add speed.

The trial session: the intervals in the 2024 trial of older women were 30 minutes: ten 2-minute bouts at 80 to 90% of maximal heart rate, with 1 minute of active recovery at 70% between them, twice a week for 8 weeks.¹² With the lower heart rates in water in mind, the practical version is ten 2-minute bouts at a hard effort, a few words at a time, with 1 minute easy between.

Practical: for a runner, count an aqua jogging session as one of the week's runs, not an extra. For VO2 max work on land, see how to improve VO2 max, and for how swimming compares with running, swimming vs running.

Aqua jogging in South Florida

Diogo Camera is an online fitness coach based in South Florida, where NOAA's 1991–2020 normals put the Miami International Airport station at 91.4 days a year at or above 90 F.¹⁵ Practical: on a hot day a deep-water session is one way to keep a hard run in the week, and running in the heat has what the heat does to a run on land. Coaching is online: online coaching in Florida.

Common questions

Is aqua jogging a good workout?

As measured: peak oxygen uptake and heart rate are lower than on a treadmill,^4,6 but trained runners kept their running fitness for 4 to 6 weeks on it,^9,11 and inactive older women improved as much as with treadmill intervals.¹²

What are the benefits of aqua jogging?

What the trials measured: running fitness held in trained runners over 4 to 6 weeks (in one study VO2 max dipped slightly with every mode while run time held), and fitness and functional tests improved in older adults.^9,10,12,13 This page makes no health or injury claim.

Is aqua jogging as good as running?

For keeping fitness over a few weeks in trained runners, the studies found no difference from running.^9,10 It doesn't train the landing and push-off on ground, and the peak numbers are lower,^6,7 so for a runner it's a stand-in, not a replacement for racing preparation (practical).

Do you need a belt for aqua jogging?

The studies used one, and it's the usual way to start. See the belt above.

How long should an aqua jogging workout be for beginners?

About 20 to 30 minutes to start, with intervals (practical). The 2024 trial's sessions were 30 minutes, twice a week.¹²

I'm a fitness coach, not a doctor: if you have pain, an injury or a health condition, ask a doctor or physical therapist before you train in deep water.

If you'd rather have the week planned

Fitting pool days, runs and lifting into one week is a planning job. Coaching is the version where your workouts are built around the days and places you actually train, and a weekly call looks at the week you just had and rebuilds the next one. Coaching explains how it works, and apply is the first step. Otherwise: try the beginner session once this week.