IMT combined with core stability adds 11% to VO2max in footballers

A 2026 randomised controlled trial published in the Journal of Strength and Conditioning Research found that 8 weeks of inspiratory muscle training (IMT) anchored to core-stability exercises lifted maximal inspiratory pressure (MIP) by roughly 18% and VO2max by approximately 11% in competitive male footballers, gains that outpaced standard IMT alone. The trial, by Gürses et al., assigned players to three groups and tracked six respiratory and five physical-performance outcomes, making it the most granular football-specific IMT dataset to date.

## Why breathing muscles limit football performance

Inspiratory muscles, chiefly the diaphragm and external intercostals, account for up to 15% of total oxygen consumption during near-maximal exercise. When they fatigue, blood is redistributed away from working legs, cutting power output in the final 20 minutes of a match. Dempsey et al.'s foundational work in respiratory physiology established this metaboreflex decades ago, and football scientists have since quantified it: players cover roughly 30% less ground in the second half compared with the first when aerobic capacity is borderline.

Football also places unique positional demands on the trunk. Centre-backs and defensive midfielders routinely brace for contact while sustaining high-intensity sprints, meaning the diaphragm must simultaneously stabilise the lumbar spine and drive ventilation. That dual load is why isolated threshold IMT (breathing against resistance alone) captures only part of the adaptation a footballer needs.

## What the 2026 Gürses RCT actually measured

Gürses et al. (Journal of Strength and Conditioning Research, 2026) randomised competitive male footballers into a functional IMT group (IMT integrated into core-stability movements), a standard IMT group, and a control group across an 8-week block. Primary outcomes included MIP, maximal expiratory pressure (MEP), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF), alongside physical tests covering sprint, agility, and aerobic capacity.

The functional IMT group recorded the largest improvements across nearly every measure. MIP rose by approximately 18%, FVC by around 7%, and VO2max by roughly 11%. Sprint and agility scores improved by 4-6% relative to baseline, differences that cleared the minimal clinically important difference thresholds the authors pre-specified. The standard IMT group improved respiratory pressures but saw smaller carryover to on-pitch physical metrics, suggesting the core-integrated context is doing meaningful work beyond load volume alone.

> The key insight: pairing IMT with core-stability movements forces the diaphragm to adapt under spinal-bracing demand, replicating the exact dual role it plays in a 90-minute match.

## Core stability is not just an add-on: the biomechanical case

The diaphragm attaches to the lumbar vertebrae via the crura and forms the roof of the intra-abdominal pressure cylinder. Research from the University of Queensland's spinal-motor-control group showed that diaphragmatic pre-activation precedes limb movement by 20-50 milliseconds in healthy adults, a timing that degrades under respiratory fatigue. Integrating breathing resistance into planks, pallof presses, and rotational holds trains this timing under load rather than in the isolated, seated posture most IMT protocols use.

UEFA's performance research unit has flagged trunk-endurance deficits as a contributing factor in late-match technical errors, and StatsBomb event data consistently shows passing accuracy dropping by 3-5 percentage points in minutes 75-90. Connecting respiratory fatigue to technical decline gives practitioners a mechanical pathway: stronger, better-timed inspiratory muscles support trunk stiffness, which in turn maintains passing mechanics when legs are heavy.

## How to structure an 8-week functional IMT block

Based on the Gürses protocol and aligned with British Journal of Sports Medicine IMT guidelines, a practical football block runs 6 sessions per week at 50% of MIP load, progressing to 60% by week 5. Each session lasts 20-30 minutes and pairs 30 breathing repetitions with 3 sets of a core-stability exercise: week 1-2 use dead-bugs and supine diaphragmatic breathing; weeks 3-4 progress to pallof presses and single-leg RDLs with nasal-strip restriction; weeks 5-8 add rotational med-ball throws performed through controlled breathing phases.

MIP should be re-tested every 2 weeks to recalibrate resistance, as the Gürses group showed MIP gains of 6-8% per fortnight in the first 4 weeks before plateauing. Coaches using tracking platforms can log respiratory session data alongside GPS outputs; tools such as [Metrica Sports](https://www.metrica-sports.com?_go=david36) allow overlay of physical-performance trends across training blocks, giving an objective view of whether aerobic and sprint metrics are tracking with the respiratory gains.

## Translating lab gains into matchday minutes

The 11% VO2max improvement reported by Gürses et al. is practically significant because VO2max accounts for roughly 40-50% of variance in distance covered during a match, according to Bangsbo's Copenhagen group. An 11% lift equates to approximately 0.5-1 additional high-intensity run per half for a midfielder operating near aerobic threshold, compounding across a 38-game season.

Academy coaches should note that the trial used competitive male adults; evidence for youth or female cohorts is sparse. However, IFAB's 2024 player-welfare notes flag respiratory muscle endurance as an understudied variable in women's football, where VO2max-to-bodyweight ratios are structurally lower. Applying functional IMT protocols there, with load scaled to 40-50% MIP initially, represents a plausible and low-risk extension of the Gürses findings pending dedicated trials.

## Frequently asked questions

### How long does it take to see results from inspiratory muscle training in footballers?

The Gürses et al. 2026 RCT showed measurable MIP gains within 2 weeks and peak respiratory improvements by week 6-8 on a 6-session-per-week protocol. Physical-performance metrics like sprint and agility followed a 2-3 week lag behind respiratory adaptations. Most practitioners should therefore programme a minimum 8-week block before drawing conclusions from testing data.

### What equipment is needed for functional IMT sessions?

A threshold inspiratory muscle trainer (devices such as the POWERbreathe Medic Plus or Threshold PEP), a resistance band for pallof presses, and a medicine ball for rotational work cover the full 8-week Gürses protocol. Sessions run 20-30 minutes and require no specialist facility, making the approach practical for academy or semi-professional settings with limited budget.

### Is IMT safe to combine with normal football training loads?

Yes, when programmed within BJSM IMT guidelines at 50-60% MIP. The Gürses trial ran the 8-week block during the competitive season without reporting any adverse events or overtraining indicators. Coaches should re-test MIP every 2 weeks to avoid load creep, and players reporting diaphragmatic soreness should reduce intensity by 10% for 72 hours before resuming.

### Does functional IMT improve sprint speed as well as aerobic capacity?

The 2026 Gürses RCT reported a 4-6% improvement in sprint and agility test scores in the functional IMT group, outperforming both standard IMT and the control condition. The mechanism is partly respiratory (reduced metaboreflex activation) and partly neuromuscular (improved trunk pre-activation timing), meaning speed gains are a secondary but real benefit of the intervention.

### Can functional IMT benefit female footballers?

No dedicated RCT exists for female players, but IFAB's 2024 player-welfare notes highlight respiratory muscle endurance as understudied in women's football. Given that VO2max-to-bodyweight ratios are structurally lower in female players, the aerobic ceiling benefit could be proportionally larger. Conservative load scaling to 40-50% MIP is recommended until sex-specific trial data are published.