Train the muscles that power every breath.
Cyclists climb harder. Runners hold pace longer. Fighters recover between rounds. Divers stay down. The O2 Trainer strengthens your diaphragm and intercostals with 10 minutes of controlled inspiratory resistance a day.
Designed by Bas Rutten
Former UFC Heavyweight Champion · Trusted by pro athletes worldwide
Higher VO₂ Max
Push your aerobic ceiling higher so you sustain race pace with less strain.
See performance gains10 Minutes a Day
Short daily sessions slot into any warm-up, cooldown, or recovery day.
See performance gainsBacked by Sport Science
Inspiratory muscle training is used by pro cyclists, rowers, and combat athletes.
See performance gains30-Day Guarantee
Train with it for a month. Don't feel the difference in your sport? Full refund.
See performance gains
When your breathing gives out, so does your pace.
At threshold your respiratory muscles start stealing blood flow from your legs — the "metaboreflex". A stronger diaphragm delays that steal, keeps your form, and protects your finishing kick. It's resistance training for the muscles nobody trains.
- Strengthens the diaphragm — the engine behind every deep breath under load
- Trains the intercostals so your rib cage expands fully at threshold
- Improves CO₂ tolerance so panic-breathing doesn't cost you a race or a round
- Delays the onset of respiratory fatigue late in efforts, rounds, or dives
Performance gains you can feel by week three.
Higher VO₂ max
Move more oxygen per breath. Riders and runners see gains in sustainable power at threshold.
Delayed lactate threshold
Hold race pace longer before your breathing pattern breaks down and lactate spikes.
Faster round & interval recovery
Fighters and interval athletes drop heart rate quicker between efforts.
Better breath-hold & CO₂ tolerance
Divers, swimmers, and spearfishers stay calm and controlled under apnea stress.
Stronger core for punches & sprints
The diaphragm is a core muscle — a stronger one means harder strikes and stiffer starts.
Portable, no batteries, no app
Train on race morning, in the hotel, or on the bus. 10 minutes, three resistance caps.
One device. Every endurance discipline.
Whatever your sport, when your breathing is the weak link, everything downstream suffers.
Cyclists
Sustain higher watts at threshold on long climbs. Recover faster between attacks and TT efforts.
Runners
Control your breathing rhythm at race pace. Hold form in the final 5K when others fall apart.
Boxers & MMA
Drop heart rate between rounds. A stronger diaphragm also means harder punches from the core.
Freedivers & swimmers
Bigger, more efficient breath capacity. Higher CO₂ tolerance for calmer, longer holds.
Rowers & CrossFit
Push through the pain cave without your breathing collapsing. Better bracing under load.
Trail & altitude athletes
Prepare your respiratory system for thinner air. A drug-free complement to altitude training.
Three steps. Ten minutes. Real gains.
Set the resistance
Three interchangeable caps go from easy to hard. Start where you can breathe cleanly for 30 breaths.
10 minutes, twice a day
Inhale hard against the resistance through the mouthpiece. Pair it with your warm-up or cooldown.
Progress the load
As your inspiratory muscles adapt, twist to a harder cap. Most athletes step up within 2–4 weeks.
"Every fighter I've trained who used the O2 Trainer came out of the later rounds fresher. Same for the runners, cyclists, and freedivers. Train the breathing muscles like any other and the difference is night and day."
— Bas Rutten · Former UFC Heavyweight Champion
"Bas I'm gonna use it every day!"
— Joe Rogan
UFC commentator, comedian, and host of The Joe Rogan Experience
Stories from athletes who trained their breath.
"By mile 20 my breathing usually falls apart. After eight weeks with the O2 Trainer I finished my last marathon still in rhythm — and took three minutes off my PB."
Elena M.
Marathon runner · 2:58 PB
"The difference between round two and round four disappeared. My corner noticed before I did. I recover between rounds like I did between rounds one and two."
Marco D.
Amateur boxer, 12–2
"CO₂ tolerance is everything down there. Ten minutes a day on the O2 Trainer added seven meters to my constant-weight dives in a single season."
Jesper L.
Freediver · –38 m
Questions, answered.
Add ten minutes. Take back your finish.
Cyclists, runners, fighters, and divers train with the O2 Trainer for one reason: when the breathing muscles hold, everything else does too. Drug-free. 30-day guarantee.
Get the O2 Trainer