You may have seen ads for “BREATHING training” devices like the PowerLung that promise to increase your lung capacity and improve your breathing so you can dive deeper and get more time out of every tank. These inhale-like products provide variable resistance against which you inhale and exhale to strengthen your respiratory muscles like those between you ribs, which some experts believe are the first to fatigue during underwater activities. In one recent study, volunteers who performed 30 minutes of respiratory training five days a week for four weeks improved their scuba swimming time by 66 percent.
Impressive results. But it’s important to note that most published studies are done on laboratory equipment, not commercial devices. “We can’t speak to the usefulness of commercial devices since we have not tested them,” says study author Claes E. G. Lundgren, M.D., Ph.D., of the State University of New York art Buffalo, who concedes that home devices could be helpful. Thirty minutes day is also a long time (though PowerLung claims benefits in just 10 minutes a day) to devote to respiratory training. But some free divers swear by it. If you feel limited by your breathing capacity, it could be worth checking out.
