Breathing training for running and triathlon gives athletes a focused way to develop respiratory endurance, usable breathing volume, and control without adding another hard session to the legs. Running, cycling, and swimming all challenge breathing, but sport training alone does not guarantee that the respiratory system receives the specific load it needs to stop being a limiter.
The goal is not to replace aerobic training, intervals, strength work, or technical practice. It is to build a more capable respiratory system that can better support those demands.
The short answer
- Train breathing off the course. Use the BWB at rest, never while running, riding, swimming, or driving.
- Begin with mechanics. Learn to access a fuller inhalation and complete exhalation before chasing intensity.
- Build sustained ventilation. Progress from short introductory sessions to longer endurance and interval programs in the app.
- Transfer the capacity to sport. Practice using larger, controlled breaths when pace, terrain, posture, and race stress change.
- Measure the result. Track breathlessness, breathing control, recovery between efforts, tidal volume, and objective testing when available.
Why endurance training may leave a respiratory gap
To make breathing hard through running, an athlete usually has to make the entire body work hard. Hill repeats, threshold intervals, and race simulations raise ventilation, but they also fatigue the legs, use glycogen, and add recovery cost. That is an inefficient way to target the respiratory muscles when the legs already receive plenty of training.
Respiratory muscles contain a substantial proportion of fatigue-resistant fibres. A handful of resisted breaths can train pressure generation, but endurance athletes need to repeat large, coordinated inhalations and exhalations for long periods. Focused respiratory training separates that task from the load placed on the legs.
How breathing can limit running and triathlon
As pace rises, the body produces more carbon dioxide and ventilation must increase. If respiratory endurance, usable volume, or coordination cannot meet the demand, athletes may switch early to smaller and faster breaths. Breathlessness rises, rhythm breaks down, and the athlete may slow even when the locomotor muscles could continue.
Breathing work also has a circulatory cost. Experimental research shows that changing respiratory muscle work during intense exercise can influence blood flow available to locomotor muscles. This does not prove that every athlete is respiratory-limited, but it supports assessing the system instead of assuming regular cardio has optimized it. Read the primary study.
Signs breathing may be limiting you
- You can hear your breathing become loud or chaotic before your legs feel finished.
- You rely on small, rapid upper-chest breaths as pace rises.
- Your breathing rhythm collapses on hills, after surges, or late in a race.
- Breathlessness makes you slow before muscular fatigue does.
- Your breathing settles slowly between intervals or disciplines.
- You struggle to access the lung volume already visible on spirometry.
These are clues, not a diagnosis. Heat, altitude, illness, pacing, anxiety, posture, asthma, and insufficient aerobic conditioning can also affect breathing. A lab assessment combining spirometry, gas exchange, tidal volume, breathing frequency, and pace provides a more objective picture.
What runners and triathletes should train
Usable breathing volume
Capacity on a spirometry test matters only if the athlete can use it under demand. Training should develop improved abdominal inhalation and expanded rib motion. followed by a complete and controlled exhalation.
Respiratory endurance
Distance performance requires sustained ventilation. The respiratory muscles must repeat effective breathing cycles while posture, cadence, terrain, and fatigue change.
Strength, power, and coordination
Developing power through increased strength can make a difference when testing identifies a weakness. The BWB can create resistance as airflow and ventilation rise, while its full-cycle design trains inhalation and exhalation together. Athletes with a specific maximal-strength deficit may combine sustained Isocapnic work with pressure-threshold training. Compare respiratory training methods.
Why Isocapnic training is different
Breathing hard at rest normally removes carbon dioxide faster than metabolism produces it. That can cause tingling, lightheadedness, and discomfort before the respiratory muscles receive enough sustained work.
The BWB uses a calibrated rebreathing circuit that recaptures a controlled portion of exhaled air while continuously admitting small amounts of fresh air into the system. During standard training, this helps maintain CO₂ and support normal oxygen saturation, allowing sustained high-volume training of both inhalation and exhalation. Learn the full method in the complete respiratory muscle training guide.
How the four stages fit running and triathlon
Stage 1: Use the warm-up as the foundation
Start with the free five-minute warm-up in the Isocapnic app before your regular training sessions. This is not merely a beginner lesson. It prepares breathing range, air movement, respiratory muscle blood flow, and control, and it can remain part of an athlete’s routine at every level.
Stage 2: Use Isocapnic training as the workout
Once the warm-up is established, use the BWB as a focused respiratory workout. Start with a five- or ten-minute balanced session, then progress through app programs for volume, endurance, strength and power, coordination, or interval capacity. Two or three specific respiratory sessions per week can fit around the athlete’s running, cycling, swimming, and strength load.
Stage 3: Add advanced methods when they serve a clear purpose
Advanced work can include interval Isocapnic training, recovery and downregulation sessions, simulated-altitude exposure, and protocols that intentionally manipulate oxygen or carbon dioxide. Follow the prescribed app settings and safety guidance. Use appropriate monitoring, including pulse oximetry when instructed, and seek practitioner oversight for advanced gas-exchange work.
Stage 4: Turn breathing into a sport strategy
Remove the device before sport. During running, cycling, swimming, and transitions, practise accessing a larger controlled breath, maintaining rhythm as pace and posture change, and regaining respiratory control after hills or surges.
The stages do not need to be completed once and abandoned. Stage 1 remains the foundation, Stage 2 deliberately develops the respiratory system, Stage 3 adds advanced applications, and Stage 4 builds ownership in sport. An athlete can use the warm-up before every workout, complete specific respiratory training two or three times per week, use an appropriate recovery session, and practise better breathing strategies in the same training phase. Read the full integration framework.
What the research shows
- A controlled study in competitive male runners reported large gains in respiratory endurance and improvements in treadmill endurance and four-mile running performance after voluntary isocapnic hyperpnea training. The study was small, so the size of the reported effect should not be treated as a guarantee. Read the study.
- A randomized study in amateur runners reported improved inspiratory and expiratory strength, time to exhaustion, perceived fatigue, and breathlessness after eight weeks of inspiratory muscle training, but no change in VO₂ max. Read the study.
- Not every intervention improves a time trial. A study of a flow-resistive mask worn during HIIT found no additional improvement in five-kilometre performance, reinforcing that the method of respiratory training matters. Read the study.
The evidence supports respiratory training as a targeted tool, not a guaranteed shortcut. Outcomes depend on the athlete, method, dose, sport demands, and whether breathing was a meaningful limitation.
Customer experience
“The panic’s gone, and now my splits hold steady all the way through.”
Paul M., verified Isocapnic customer. Individual experience, not a guaranteed result.
Isocapnic has worked with elite endurance athletes who consider respiratory training part of their competitive advantage. Training with BWB is most useful when combined with repeatable assessments and progressive training. Explore more Isocapnic customer experiences.
For related endurance examples, read the historical features on ultra-running respiratory demands and air hunger in endurance performance. These articles provide context and athlete experience, while the controlled studies above provide stronger evidence for cause and effect.
How to measure progress
- Breathing feels less laboured at a familiar pace or power.
- You maintain rhythm and access deeper breaths later in hard efforts.
- Breathing settles sooner between intervals or disciplines.
- You can sustain a harder respiratory efforts with good technique.
- A repeatable bag-volume reference shows increased comfortable tidal volume.
- Standardized testing shows changes in spirometry, ventilation, breathing frequency, pace, or power.
BWB-Sport or BWB-Mask?
- BWB-Sport is the simplest and most portable option for most runners and triathletes. It packs easily for races, camps, and poolside use.
- BWB-Mask provides hands-free oral or nasal training and can be more comfortable for longer sessions.
Frequently asked questions
Should I use the BWB while running, cycling, or swimming?
No. Use the BWB at rest in a safe setting. Finish the session and remove the device before sport.
Does respiratory training replace VO₂ max intervals?
No. Sport intervals train the integrated cardiovascular, metabolic, neuromuscular, and technical system. Respiratory training adds a focused stimulus with less peripheral fatigue.
How often should I train?
Use the five-minute Stage 1 warm-up before regular training sessions. For Stage 2, two or three specific respiratory workouts per week is a practical starting structure. Progress duration and difficulty through the app when technique is consistent and the current program no longer creates meaningful fatigue. The warm-up and the respiratory workout are different training uses.
The takeaway
Running and triathlon training already place a large load on the body. Focused Isocapnic training gives athletes a way to train the respiratory system independently, then brings greater breathing capacity and control back to the sport. Start with mechanics, progress to more challenging programs within the app, and judge the result by whether breathing becomes less limiting in training and racing.
This article is intended for athletic and general wellness education. BWB products are not medical devices for diagnosis or treatment. People with respiratory, cardiovascular, or other health conditions should consult their clinician before beginning respiratory training. Follow the app, manual, and safety guidance. Stop if you feel dizzy, lightheaded, or unwell. Individual results vary.
AUTHORSHIP AND TRANSPARENCY
About this article
Written by
Dr. Andrew Sellars is a Canadian physician, anesthesiologist, performance physiologist, entrepreneur, and coach with a Master's degree in Athletic Coaching. He co-founded VO2 Master and is Co-Founder, Chief Science Officer, and Physiology Advisor at Isocapnic Technologies Inc., where his work focuses on biomarker-guided training and respiratory performance.
