This content originally appeared on Everyday Health. Republished with permission.

Written By Lisa Rapaport

People with chronic health issues that make it challenging to exercise may benefit from high intensity interval training (HIIT) workouts done in a swimming pool, a new study suggests.

While HIIT workouts can improve exercise capacity — measured by how efficiently the body uses oxygen during workouts and endurance during walking and fitness tests — many people with chronic medical problems have physical limitations that make it difficult to do this type of activity. For a new study, scientists wanted to see if HIIT workouts done in water, which can be less taxing on the joints, might be an effective way to boost exercise capacity for people who have a hard time with workouts on land.

Scientists examined data from 18 clinical trials with a total of 868 adult participants who had a range of medical conditions that might make HIIT workouts challenging, such as type 2 diabetes, chronic obstructive pulmonary disorder, osteoarthritis, and peripheral artery disease. All of the trials looked at the effectiveness of aquatic HIIT workouts as compared with either no exercise, land-based HIIT, or moderate-intensity exercise in the water.

They found that aquatic HIIT improved exercise capacity just as much as HIIT workouts done on land, according to results published in BMJ Open Sport and Exercise Medicine.

“Those interested in high-intensity water training might find it beneficial to give it a try, particularly if they have struggled with HIIT on land or found such exercises too demanding,” says lead study author Heidi Bunæs-Næss, who works in the department of rehabilitation science and health technology at Oslo Metropolitan University in Norway.

“It could potentially be a successful environment to initiate and continue high-intensity training,” Bunæs-Næss says.

Consistency With Aquatic HIIT

One advantage of aquatic HIIT is that people stick with it. Across all of the smaller studies included in the analysis, 84 to 100 percent of the participants asked to do aquatic HIIT workouts completed these workouts as directed.

This consistency may play a role in how much aquatic HIIT workouts help boost exercise capacity, says Danilo Sales Bocalini, PhD, a professor at the Physical Education Sport Center of Federal University of Espirito Santo in Vitória, Brazil.

RELATED: 7 Pool Exercises for a Fat-Burning Water Workout

“Practicing activities in a liquid environment has some advantages, especially for those who have musculoskeletal disorders or even motor limitations that prevent locomotion or motor gestures in a terrestrial environment,” says Dr. Bocalini, who wasn’t involved in the new study.

Both types of HIIT workouts, however, can be equally effective, and the ideal choice may come down to which type of exercise is most feasible and enjoyable, and what people can stick with consistently.

Specialized Equipment for HIIT Workouts in the Pool

Specialized equipment may not be required, but depending on the workout, there are some things that might help enhance the safety and effectiveness of exercising in the water, Bocalini adds. Fins, with or without weights, can add intensity. And water socks or shoes with added grip on the bottom can help with aquatic running and prevent scrapes or other injuries from rough pool surfaces.

Because the study looked at a wide variety of aquatic activities, it doesn’t offer any insight into what type of aquatic workout might be most beneficial, Bunæs-Næss says. Aquatic HIIT workouts can include options like lap swimming, cycling or running in water, or doing resistance training with weights in the pool.

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With all of these workouts, buoyancy in the water may make it easier for people to complete longer or more intense HIIT routines than they could do on land, says Billy So, PhD, an assistant professor of rehabilitation sciences at Hong Kong Polytechnic University who wasn’t involved in the new study.

“Support from buoyancy may lead to exercise being more feasible and enjoyable for people who are unable to train effectively on land by addressing barriers to HIIT, including weakness or pain, that affect exercise performance and intensity,” Dr. So says.

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