Unlocking Performance: The Power of Breathing in Functional Fitness

Breathing is one of the simplest tools I can use to improve performance and recovery. Most people think breathing is only about getting more oxygen in, but it is really about balance. Oxygen and carbon dioxide work together to help the body produce energy, control effort, and recover after training.

The Oxygen-Carbon Dioxide Dynamic

Oxygen helps my muscles create energy. When I inhale, oxygen enters my lungs, moves into my blood, and attaches to hemoglobin inside red blood cells. Hemoglobin carries oxygen to the working muscles. Carbon dioxide is produced when my body uses that oxygen for energy. As exercise gets harder, my muscles produce more carbon dioxide. My brain responds by increasing my breathing to help remove the extra carbon dioxide and keep my blood chemistry balanced (Benner et al., 2023).

Carbon dioxide is also important because it helps oxygen leave the blood and enter the working muscles. This is called the Bohr effect. When carbon dioxide rises in active muscle tissue, hemoglobin releases oxygen more easily. In simple terms, oxygen feeds the muscles, but carbon dioxide helps unlock oxygen delivery where the body needs it most (Benner et al., 2023; Jensen, 2004).

This is why breathing is not just about taking bigger breaths. Overbreathing can actually make me feel more anxious, tense, and out of control. Better breathing means learning how to use oxygen efficiently while tolerating the natural rise of carbon dioxide during effort.

Understanding Carbon Dioxide Tolerance

Carbon dioxide tolerance is my body’s ability to stay calm when CO2 rises. During hard workouts, CO2 increases and creates the urge to breathe harder. If I have low CO2 tolerance, that feeling can turn into panic breathing. My shoulders rise, my breath becomes shallow, my heart rate climbs quickly, and I may redline too early. With better CO2 tolerance, I can stay composed, control pacing, and recover faster between efforts. Research shows that carbon dioxide influences breathing drive and the feeling of breathlessness during exercise (Harrison et al., 2022).

Breathing for Athletic Performance

Breathing Techniques for Long Runs

For long runs, breathing should create rhythm. I start with nasal breathing when possible. This helps slow my breath and keeps my pace controlled. I try inhaling for 3 steps and exhaling for 3 steps. As the pace increases, I shift to inhaling for 2 steps and exhaling for 2 steps. If my breathing becomes frantic early, the pace is probably too aggressive.

Breathing Techniques for Sprints

For sprints, the goal is power with control. I take 1 or 2 deep breaths before the sprint. After the sprint, I walk tall and bring my breath down. I try inhaling through my nose for 3 seconds and exhaling through my mouth for 5 to 6 seconds. The longer exhale helps calm my nervous system so the next effort can be stronger.

Breathing Techniques for Metcons

For metcons, breathing can keep the workout from becoming chaotic. I match my breath to the movement. I exhale when throwing a wall ball, driving on the rower, swinging the kettlebell, jumping on the box, or standing out of a squat. I use transitions as breathing checkpoints. One full breath before moving to the next station can prevent early panic and help me stay in control.

Breathing Techniques for Lifting

For lifting, breathing supports bracing. Before a heavy squat, deadlift, clean, or press, I take a deep breath into my belly and ribs. I brace like I am about to take a punch. I hold that brace through the hardest part of the lift, then exhale once the rep is complete or past the sticking point. For lighter lifts, I inhale before the effort and exhale during the effort.

Breathing for Recovery

Breathing also helps recovery. During intense training, my body shifts into the sympathetic nervous system. This is the fight or flight state. My heart rate rises, my breathing speeds up, and my body prepares to work. After training, the goal is to shift into the parasympathetic nervous system. This is the rest and recover state. Slow breathing can help with that shift.

After a workout, I try breathing in through my nose for 4 seconds and breathing out through my nose for 6 to 8 seconds. I repeat this for 2 to 5 minutes. Longer exhales can help lower arousal and support parasympathetic recovery. Slow breathing has been linked to improved heart rate variability, which is often used as a marker of nervous system recovery (Laborde et al., 2022). Paced breathing may also improve carbon dioxide regulation and relaxation over time (Szulczewski, 2019).

The Long Game: Resetting for Success

Breathing will not replace training, sleep, nutrition, hydration, or consistency. But it can make those things work better. An athlete who breathes well can pace smarter, stay calmer under pressure, recover faster, and build better capacity over time. The long game is not only about how hard I can push. It is also about how well I can reset.

References

• Benner, A., Patel, A. K., Singh, K., & Dua, A. (2023). Physiology, Bohr effect. StatPearls Publishing.

• Harrison, O. K., Finnegan, S. L., Köchli, L., Hayen, A., Pattinson, K. T. S., & Faull, O. K. (2022). Perceptual and ventilatory responses to hypercapnia in athletes and sedentary individuals. Frontiers in Physiology, 13, 820307.

• Jensen, F. B. (2004). Red blood cell pH, the Bohr effect, and other oxygenation linked phenomena in blood oxygen and carbon dioxide transport. Acta Physiologica Scandinavica, 182(3), 215 to 227.

• Laborde, S., Allen, M. S., Borges, U., Dosseville, F., Hosang, T. J., Iskra, M., Mosley, E., Salvotti, C., Spolverato, L., Zammit, N., & Javelle, F. (2022). Effects of voluntary slow breathing on heart rate and heart rate variability. Neuroscience & Biobehavioral Reviews, 138, 104711.

• Szulczewski, M. T. (2019). Training of paced breathing at 0.1 Hz improves CO2 homeostasis and relaxation during a paced breathing task. PLOS ONE, 14(6), e0218550.