Smarter Breathing, Stronger Racing: Your Guide to Better Performance Without Extra Training

Why Breath Training Matters More Than You Think

Boost endurance performance for your next race in Singapore's heat and humidity without adding training load, just by upgrading how you breathe. Whether you're preparing for a 10K, a trail run, a half-marathon, a long gran fondo on the bike, or a multi-day outdoor adventure, breath training can make your efforts feel smoother, stronger, and more controlled.

This article isn't about overhauling your program.

It's about unlocking efficiency in the one system that's working continuously during every stride, pedal stroke, and climb.

Breathing is one of the few performance variables endurance athletes simultaneously overuse and under-train. During hard efforts, the work of breathing can consume 10-15% of total oxygen uptake, and when breathing muscles fatigue, a reflex response diverts blood flow away from the working legs, accelerating fatigue [Effects of respiratory muscle work on exercise performance | Harms et al. | 2000].

This isn't a minor detail. Reducing the work of breathing during intense exercise increases circulation to the legs and improves whole-body performance, while increasing breathing load does the opposite [Respiratory muscle work compromises leg blood flow during maximal exercise | Harms et al. | 1997]. Put simply: your breath directly influences how well your legs are supplied during demanding efforts.

When breathing is trained deliberately, performance follows. In trained athletes, respiratory muscle training can improve real time-trial performance by 3-5%, extends endurance, and reduces perceived effort [Effects of respiratory muscle training on performance in athletes: a systematic review with meta-analyses | HajGhanbari et al. | 2013]. These gains require no extra mileage, intensity, or mechanical load.

Improvements are often larger in non-elite athletes, where inefficient breathing patterns are more common and breathing muscles are less conditioned [Effects of respiratory muscle training on performance in athletes: a systematic review with meta-analyses | HajGhanbari et al. | 2013]; [Respiratory muscle training in healthy humans: resolving the controversy | McConnell & Romer | 2004].

Long before the physiology was formalised, elite performers reached the same conclusion through experience: from Emil Zátopek's breath-restricted intervals and Mizuki Noguchi's heat-proof marathon, to Paula Radcliffe's asthma-managed pacing, Eliud Kipchoge's quiet efficiency, and Singapore's Yeo Boon Kiak thriving through repeated surges. The world's best consistently share one trait: they move faster while breathing less.

With the big picture in place, let's break down each breathing skill and how it improves performance.

Inspiratory muscle strength - the forgotten engine

During harder training, your diaphragm and intercostal muscles demand a significant portion of blood flow. When they fatigue, a protective reflex diverts blood away from the legs, raising heart rate and perceived effort even when pace stays constant [Respiratory muscle work compromises leg blood flow during maximal exercise | Harms et al. | 1997].

Reducing breathing fatigue helps to maintain circulation to the working muscles, while extra breathing load accelerates exhaustion [Effects of respiratory muscle work on exercise performance | Harms et al. | 2000]. This is why strengthening the breathing muscles can improve endurance without changing your fitness or pacing strategy.

Inspiratory muscle training (IMT) reliably improves both short and long time-trial performance and reduces breathlessness [Effects of inspiratory muscle training on time-trial performance in trained cyclists | Romer et al. | 2002]. A practical starting point is 30 resisted inhalations, 3-5× per week for 4-6 weeks using a flow-resistive device.

Start at ~50-60 % of maximal inspiratory pressure (or a comfortable resistance that allows full sets with good form), and progress from there. Benefits appear after 4–6 weeks of consistent use. You can get common devices like PowerBreathe, or fancy Airofit, or just a simple IMT device from Lazada for less than $10 that will do the trick.

Look for an adjustable resistance device (rather than a fixed one) so you can start at a comfortable level and progressively increase the load as your inspiratory muscles get stronger.

Foundational Mechanics: Belly Before Chest

Before diving into resistance devices or breath holds, ensure you are breathing with your diaphragm rather than shallowly lifting your upper chest. Focus on expanding your abdomen and lower ribs 360 degrees on the inhale while keeping your shoulders relaxed, followed by a gentle, natural recoil of the belly on the exhale.

To master your breathwork, check our Community calendar to join one of our upcoming live breath sessions and refine your technique together with us!

CO₂ tolerance - controlling the urge to panic

Your urge to breathe harder during demanding moments is driven primarily by rising carbon dioxide, not low oxygen. Athletes with low CO₂ tolerance react to small increases with rapid, shallow breathing, elevated heart rate, and unnecessary stress [Consequences of exercise-induced respiratory muscle work | Dempsey et al. | 2006].

This elevates breathing effort and accelerates fatigue, even when aerobic fitness is high [Hypercapnia and Ventilatory Control | Dempsey et al. | 2008]. Athletes with higher tolerance maintain smoother breathing patterns, steadier heart rates, and better control during demanding periods.

CO₂ tolerance can be trained safely using controlled, sub-maximal breath holds and slow-breathing drills that reduce sensitivity without inducing hypoxia [Cardiovascular responses during hypoventilation at exercise | Woorons et al. | 2011]. The aim is comfort under mild breath hunger-not maximal breath holding.

Short CO₂ Tolerance Table (Intro Level)

This beginner-friendly intro-level CO₂ table consists of 7 rounds with a fixed 30-second breath hold (after inhale) and progressively shorter recovery breaths, decreasing from 45 seconds down to a minimum of 15 seconds. Do not hyperventilate between rounds. Perform it seated, lying down, or (with caution) while walking to build tolerance to rising CO₂, improve breathing efficiency, and enhance pacing under fatigue.

Timing Helpers: The Easiest Way to Get Started

Let your device handle the timing. Follow the cues and focus on staying relaxed-this makes CO₂ training simple, safe, and repeatable.

Author's note: If any round feels edgy, keep the 30-second holds but pause the rest-time descent. Repeat the same rest once before shortening again. As comfort improves, extend breath holds gradually. These sessions are easy to do while relaxing at home.

Nasal breathing - efficiency in heat and humidity

Once your breathing muscles and CO₂ tolerance improve, the next step is improving how air enters your system during real-world efforts.

Nasal breathing filters, humidifies, and warms incoming air, reducing airway irritation and improving ventilatory efficiency during extended efforts [Effect of nasal versus oral breathing on VO2max and physiological economy in recreational runners | Dallam et al. | 2018]. It also delivers nitric oxide from the sinuses into the lungs, where it enhances blood flow and oxygen exchange [High nitric oxide production in human paranasal sinuses | Lundberg et al. | 1995].

In Singapore's hot, humid conditions, these effects help moderate breathing rate and reduce unnecessary ventilation, which otherwise accelerates fatigue.

Athletes trained to nasal-breathe at comfortable training paces often show similar performance with lower ventilation and reduced perceived effort [Effect of nasal versus oral breathing on VO2max and physiological economy in recreational runners | Dallam et al. | 2018].

Nasal breathing is best introduced gradually during easy and steady efforts. A simple starting point: nasal-only breathing on easy runs, 2× per week, expanding to more sessions as it feels sustainable. The goal is smoother, more efficient breathing patterns that naturally carry into harder sessions.

At true maximum efforts like the final sprint, hard intervals, or the closing stages of a race, mouth breathing is completely fine and often necessary. Nasal airflow alone cannot meet the highest ventilation demands and can reduce peak ventilation, limiting maximum oxygen uptake in non-adapted individuals. [Nasal vs Oral Breathing During Maximal Exercise | Morton et al. | 1995]

Rhythm breathing - stabilising pace under fatigue

Rhythm breathing links breath timing to movement, synchronising inhalation and exhalation with strides or pedal strokes. This reduces variability, lowers perceived effort, and helps maintain steady pacing as fatigue builds [Analysis of co-ordination between breathing and exercise rhythms in man | Bernasconi & Kohl | 1993].

Late in races or in tougher segments, rhythm breathing reduces the cognitive load of breathing and helps maintain form under pressure [Spontaneous Entrainment of Running Cadence to Music Tempo | Van Dyck et al. | 2015]. It serves as an anchor when pacing becomes harder to judge.

Example of holding pace during a race (Radek 2025 Canmore Half Marathon)

Common rhythm breathing patterns

Use rhythmic breathing when pace sharpens, then allow breathing to relax naturally when intensity drops. Its value lies in restoring control, not enforcing strict counting. You can experiment with variations like 4:3 if your current rhythm feels too fast or rushed. Many athletes find it more comfortable at moderate paces.

From Framework to Reality - How Great Athletes Actually Breathe

The principles above aren't theoretical. Long before sports science formalised the mechanisms, elite athletes discovered that how they breathed during demanding moments determined how long they could hold pace.

What united them wasn't a single method, but a shared outcome: their best performances came when breathing stayed composed under heat, fatigue, pressure, and chaos. Through today's lens, their habits align closely with the four breathing skills outlined earlier.

Yeo Boon Kiak - controlled breathing in chaotic racing

Result: SEA Games bronze medalist; 3x Singapore national road & time-trial champion

Yeo Boon Kiak competes in one of cycling’s most physiologically unforgiving formats: hot, humid road races and high-speed criteriums where positioning, surges, and recovery happen constantly. In these races, brute fitness alone isn’t enough-poor breathing control shows up immediately as tension, loss of focus, or missed moves.

Credit: Yeo Boon Kiak IG @BOONKYEO

Dr. Yeo has spoken about the importance of composure during aggressive racing, particularly in Singapore’s heat, where over-ventilation accelerates fatigue. His success reflects a familiar pattern across endurance sports: athletes who regulate breathing during repeated accelerations recover faster, make clearer decisions, and stay effective deeper into races where others fall behind.

Emil Zátopek - stress tolerance at any cost

Result: 3× Olympic gold (5,000 m, 10,000 m, marathon) at the 1952 Helsinki Games

Emil Zátopek’s training methods still sound extreme. In the 1950s, he routinely ran hard intervals while deliberately restricting his breathing, sometimes holding his breath during repeats. He went on to win Olympic gold in the 5,000 m, 10,000 m, and marathon, despite never having raced a marathon before.

What Zátopek was really training was tolerance to respiratory discomfort. By functioning under intense air hunger, he learned to stay relaxed as CO₂ levels rose, the point where most runners tighten and slow. While his methods wouldn’t be recommended today, the principle remains: athletes who cope better with respiratory stress maintain form and pace longer.

Mizuki Noguchi - calm breathing in brutal heat

Result: Olympic marathon gold, Athens 2004 (extreme heat)

Mizuki Noguchi's Olympic marathon win came in oppressive heat, relentless sun, and on a hilly course that broke many favourites. Noguchi didn't just survive the conditions-she ran away from the field late.

Observers noted how effortless she looked: low shoulders, steady breathing, smooth pace changes. That calm was trained. Noguchi prepared extensively in hot conditions and prioritised effort control over speed, allowing her breathing to stay rhythmic and economical when others tipped into distress. She didn't out-suffer the field-she out-regulated them.

Paula Radcliffe - breathing control as survival skill

Result: Marathon world record (2:15:25), stood for 16 years

Paula Radcliffe's career was shaped by exercise-induced asthma. From her teens, she had to manage airways that could narrow under stress, cold, or pollution. Quitting wasn't an option, so she learned to control her pace, effort, and breathing.

Radcliffe became meticulous about staying calm early in races, avoiding sharp surges that could trigger respiratory distress. The payoff was extraordinary: a marathon world record that stood for 16 years and performances that often strengthened as races became more uncomfortable. For her, breathing wasn't a marginal gain-it was non-negotiable.

Eliud Kipchoge - the art of breathing less

Result: Marathon world record holder; first human to run sub-2 hours (controlled conditions)

If Zátopek represents brute-force experimentation, Eliud Kipchoge represents the opposite. Watch Kipchoge at world-record pace and what stands out isn't strain. It's the quiet. His breathing appears low, steady, and unhurried.

Kipchoge rarely speaks about breathwork explicitly, but his training philosophy centres on rhythm, calm repetition, and mental economy. His breathing stays synchronised with movement as effort rises. He doesn't fight his breathing to go faster. He goes faster because his breathing stays under control.

Why these stories matter

None of these athletes followed a modern breathing checklist. What they shared was an intuitive understanding that performance collapses when breathing becomes chaotic. Today, we're simply better equipped to train those same traits deliberately, safely, and efficiently. And yet most athletes never take full advantage. Let's fix that.

Integrating breathing into real training weeks

Breathing work should enhance your training, not interrupt it. Use the guide below to match each method to session type.

A final note before race day

On race day your fitness is already in place. What you can still control is your breathing. When the pace picks up or nerves appear, start by settling your breath. It will steady everything else. Smooth, calm breathing early on keeps options open later and helps you handle the hard moments when they come. You’ve trained for this.

Trust the work you've put in. Stay calm, stay steady. Enjoy the race!