Your diaphragm and rib muscles work about 20,000 times a day. Like any muscle, they respond to resistance.

The Breath Trainer adds it. You breathe in and out through the mouthpiece, and an adjustable valve makes the air harder to move. You'll feel it in the first thirty seconds.

Thirty slow breaths, five minutes, once a day. Start low and turn the dial up as it gets easier — that's the whole progression.

Key features:

• Adjustable resistance — Turn it up as you get stronger, so the exercise keeps up with you.
• Trains both directions — Inhalation and exhalation, adjusted separately. Cheaper trainers only resist the inhale.
• Five minutes a day — Short enough that you'll actually keep doing it.
• 37 g, pocket-sized — Lives in a handbag, gym bag or car door.
• Nothing to charge — No batteries, no app, no subscription. Works the same in year three.

Who it's for:

Runners, cyclists and swimmers training something their programme ignores. Singers, wind and brass players who need breath control on demand. Anyone who wants a short, physical wind-down at the end of the day.

Sitting down, no floor space, no fitness level required to start.

Worth knowing:

This is exercise equipment, not a medical device. It isn't intended to diagnose, treat, cure or prevent any condition.

Speak to your doctor first if you have a diagnosed respiratory or heart condition, are pregnant, or have had recent chest or abdominal surgery.