No one has to teach you to breathe: Like your heartbeat, breathing is an automatic process. Yet various websites promote an array of hand-held devices that supposedly train you to breathe better in order to improve exercise performance and reduce exercise-related fatigue. Called “respiratory muscle trainers” and going by such brand names as Expand-A-Lung, Powerbreathe, and PowerLung, the devices are also promoted for people with various ailments, singers, and musicians who play wind instruments, as well as for general good health.
The sales pitch often goes like this: “Runners think about training their heart and legs, but they rarely think about training their lungs.” The devices sell for anywhere from $25 to $600.
The devices are meant to train the muscles involved in breathing—including the diaphragm and the intercostals (the muscles between the ribs)—using the principles of resistance training. That is, you inhale and exhale through the mouthpiece to work against resistance. The devices, which look similar to asthma inhalers, may have a spring-loaded valve or other ways to adjust the tension, analogous to adding resistance on a weight machine. The idea is that you can strengthen your breathing muscles as you can other muscles, and thus can perform harder and longer without becoming breathless. Can you really breathe your way to a faster swim, a better tennis game, or an easier bike ride?
Putting breath training to the test
Though breath training has been studied for years, it remains controversial. There’s some evidence that respiratory muscle training reduces the perceived effort of exercise, improves blood flow to the limbs, and makes the muscle fibers involved with respiration more resistant to fatigue. Of the devices on the market, Powerbreathe has the most studies behind it, done over the past two decades and focusing almost exclusively on exercise or sports. Here are three examples:
- In a small Australian study in the Journal of Strength and Conditioning Research in 2014, young recreational male soccer players were divided into three groups: one that used the Powerbreathe device twice a day (30 breaths each time), one that used a disabled Powerbreathe device, and one that used no device. The first two groups also did pre-season soccer training. After six weeks, only the active-device group had an improvement in distance running (but in no other fitness-related measures).
- In a small Russian study in Body Metabolism and Exercise in 2015, young fit men cycled to exhaustion both before and after using Powerbreathe daily for three weeks. Their exercise performance improved after using the device, and respiratory muscle fatigue was delayed.
Does it make much of a difference?
It’s not clear how much respiratory muscle training translates into a boost in athletic performance or other practical benefits, especially for the average person. Studies have been small, have usually focused on athletes or highly trained people, and have often been funded by or had involvement of the device manufacturers. Not all have yielded positive results. Indeed, some have found that the devices provide no benefit when added to regular conditioning exercise. Keep in mind that for healthy people the respiratory system is rarely a limiting factor in how much exercise they can do. Though it’s possible that people with certain respiratory problems—such as chronic obstructive pulmonary disease (COPD)—may benefit from respiratory training, that remains unproven.
Bottom line: One important benefit of aerobic exercise is that it enhances both the cardiovascular and respiratory systems. Thus, exercise is the best way to improve breathing efficiency—that’s part of the so-called training effect. If you’re an athlete or just exercise regularly and want to try one of these respiratory training devices, don’t think it can substitute for your regular training. Beware of farfetched marketing claims that using a breathing device will counter the effects of smoking, pollution, or poor physical condition. If you have a disorder that affects lung function, discuss respiratory training with your doctor before buying one of the devices.
Also see Is Mouth Breathing a Problem?