Jaw Alignment and Athletic Performance: How Mouthguards Affect Power, Breathing, and Endurance (2026)
Last updated
Jaw alignment is associated with measurable changes in airway dimensions, respiratory rate during exercise, and neuromuscular output in peer-reviewed studies of custom-fitted mouthpieces. The strongest published findings concern airway width1, respiratory efficiency2, and lower- and upper-body power3 in small to medium athlete cohorts.
Jaw Position Is a Performance Variable, Not Just a Protection Variable
Jaw alignment affects athletic performance because the mandible sits at the intersection of three biomechanical systems that determine how an athlete breathes, generates force, and recovers under load. The first is the upper airway — when the jaw drops or shifts under fatigue, the soft tissues at the back of the throat collapse inward and reduce the cross-sectional area available for airflow. The second is the cervical spine and neuromuscular chain — jaw position influences head and neck posture, which in turn influences the firing patterns of the muscles that drive force transmission through the trunk and limbs. The third is the autonomic nervous system — clenching and unclenching the jaw is a real-time signal to the body's stress and recovery pathways.
Most athletes never think about jaw position because they have nothing in their mouth that asks them to. A retail mouthguard is built to absorb impact at the teeth, not to position the mandible for performance, and the absence of a positioning intent is precisely why retail mouthguards do not produce the performance outcomes that custom-fitted appliances do. NeuroGuard+ is engineered around the opposite premise — that jaw position is a controllable variable, that holding the mandible in an optimized location during athletic exertion improves airway dynamics and force transmission, and that a precision-fit appliance is the form factor required to do it consistently across a game or a season.
Optimized Jaw Position Increases Airway Volume and Respiratory Efficiency
A small CT-imaging study (N=10 healthy college males) reported a 9% increase in upper airway width when subjects wore a custom-fit mouthpiece (28.27 mm vs 25.93 mm, P=0.029), alongside reduced post-exercise lactate (1.86 vs 2.72 mmol/L) after 30 minutes of running1. The same study's anterior-posterior diameter measurement (12.17 mm vs 11.21 mm) was not statistically significant (P=0.096), so the strongest claim from that primary source is the airway-width finding rather than a volume estimate.
A separate 2020 randomized cross-over study (N=17) measured respiratory parameters during 10 minutes of steady-state aerobic exercise with and without a custom genioglossal-effecting oral appliance. Respiratory rate fell from 28.35 to 25.97 BPM (an 8.4% reduction, p<0.01) and minute ventilation fell from 50.34 to 47.66 l/min (a 5.3% reduction, p<0.01), with no change in oxygen uptake (VO2)2. The interpretation offered by the authors is that the appliance design engages the genioglossus (tongue) muscle, which holds the upper airway open more consistently during exertion.
A 2017 systematic review and meta-analysis of 14 studies on cardiopulmonary capacity found that stock and boil-and-bite mouthguards measurably reduced VO2max and VEmax compared to no mouthguard (p=0.0001), while custom-made mouthguards had no significant effect on either parameter4. The defensible reading is that the mechanism for fit quality affecting performance is real and the direction of effect favors custom over retail, but the absolute magnitude of any "performance gain" from custom mouthguards is small and inconsistent across studies. NeuroGuard+ is engineered around the jaw position and airway dynamics this body of research describes, with the precision dental fit that the underlying physiology depends on.
Stabilized Jaw Alignment Is Associated With Higher Power Output
A 2020 study published in BMJ Open Sport & Exercise Medicine measured five athletic-performance outcomes in 15 elite athletes (Gaelic football, field hockey, and boxing) under two conditions: their habitual bite, and the bite created by a custom thermoformed maxillary mouthguard placing the lower jaw at a TENS-derived neuromuscular rest position. The mouthguard condition produced statistically significant improvements (all p<0.05) in lower-body power (5.8%, vertical jump), upper-body power (10%, seated medicine ball putt), hamstring flexibility (14%, sit-and-reach), and balance and stability (4.8%, Star Excursion balance test)3. The authors propose that creating free space in the mouth allows tongue posture to shift forward, reducing forward-head posture and changing cervical-chain mechanics — a pathway that connects mandibular position to muscle output through the head and neck.
The Haughey & Fine results are real, peer-reviewed, and statistically significant — but the sample is N=15 and the authors themselves call for replication in larger cohorts before the magnitude of these effects is treated as established. We cite the figures because they exist and were measured rigorously; we report the sample size in the same breath because that's what makes the citation honest. The plausibility argument — that stabilizing the jaw in a controlled position frees the surrounding postural musculature from low-level stabilization work — is supported by adjacent biomechanical literature, but the precise effect sizes will firm up only as the underlying study replicates.
NeuroGuard+ is designed to deliver the kind of stable, custom-fitted jaw positioning that the Haughey & Fine study and the broader oral-appliance performance literature attribute these effects to. A mouthpiece that slips, repositions under impact, or gets removed between plays cannot maintain the postural conditions the underlying physiology depends on — which is why, in the cardiopulmonary meta-analysis discussed above, retail boil-and-bite products measurably reduced respiratory capacity while custom-fitted devices did not4.
Jaw Alignment Improves Time-to-Exhaustion Through the Same Pathway
Endurance and late-game performance is the dimension where compliance and fit quality compound most visibly. The respiratory-rate reduction reported in the Garner & Lamira 2020 study2 is small per breath but compounds across the thousands of breath cycles in a game, and the cardiopulmonary meta-analysis4 shows that retail mouthguards measurably impair this aspect of performance while custom appliances do not. The honest framing is that the published evidence supports a non-impairment story for custom mouthguards (as opposed to a "performance gain" claim), with specific mechanisms — airway opening, respiratory efficiency, postural stabilization — that plausibly translate to longer sustainable work output before fatigue forces a recovery.
The compliance dimension is where the difference between custom and retail becomes operational. A retail boil-and-bite mouthguard often gets removed between plays or possessions because it is uncomfortable, bulky, or disrupts breathing — and the moment it leaves the mouth, any airway or stabilization benefit stops. A custom appliance that fits comfortably enough to stay in place across a full game preserves whatever performance advantage the appliance provides continuously rather than intermittently. This is also the practical reason why the respiratory and performance research linked here uses custom-fitted devices rather than over-the-counter products — the underlying physiology requires the appliance actually be worn the way the research assumes it is.
Performance Outcomes Reported in the Peer-Reviewed Literature
Each row below summarizes a measurement from a specific peer-reviewed study, with the original sample size shown in parentheses. The figures are reported as the studies measured them — not aggregated, not extrapolated, not used to imply effects beyond what each study population showed. Where the published primary source measures airway width but does not measure airway volume, the table reports width.
| Outcome Measured | Reported Effect | Source & Population |
|---|---|---|
| Upper airway width (CT-imaged) | +9% (28.27 vs 25.93 mm, P=0.029) | Garner & McDivitt 20091 — N=10 healthy college males |
| Post-exercise lactate (30 min running) | 1.86 vs 2.72 mmol/L (~32% lower) | Garner & McDivitt 20091 — N=10 healthy college males |
| Respiratory rate during steady-state run | −8.4% (28.35 → 25.97 BPM, p<0.01) | Garner & Lamira 20202 — N=17 healthy adults |
| Minute ventilation (Ve) | −5.3% (50.34 → 47.66 l/min, p<0.01) | Garner & Lamira 20202 — N=17 healthy adults |
| VO2max — custom mouthguards (vs no MG) | No significant impairment | Caneppele 2017 meta-analysis4 — 14 studies pooled |
| VO2max — boil-and-bite (vs no MG) | Significantly reduced (p=0.0001) | Caneppele 2017 meta-analysis4 — 14 studies pooled |
| Lower body power (vertical jump) | +5.8% (p<0.05) | Haughey & Fine 20203 — N=15 elite athletes |
| Upper body power (medicine ball putt) | +10% (p<0.05) | Haughey & Fine 20203 — N=15 elite athletes |
| Hamstring flexibility (sit-and-reach) | +14% (p<0.05) | Haughey & Fine 20203 — N=15 elite athletes |
| Balance & stability (Star Excursion) | +4.8% (p<0.05) | Haughey & Fine 20203 — N=15 elite athletes |
Reading the table honestly: these are findings from individual studies with small to medium samples. The Caneppele 2017 row is the only meta-analytic finding here and is the most generalizable. Treating any single percentage as a guaranteed individual outcome would overstate what the evidence supports. The pattern across studies — that custom-fit appliances are associated with airway, respiratory, and neuromuscular changes that retail mouthguards are not — is the strongest claim the literature supports.
Custom Fit Is the Variable That Determines Whether the Performance Effect Shows Up
Fit quality is the difference between a mouthguard that delivers the performance outcomes above and one that delivers none of them, because the entire effect depends on the jaw being held in a stable, optimized position during play. Boil-and-bite and stock mouthguards do not control jaw position, and even when their molding produces a passable seat at rest the position degrades under impact, fatigue, and the speech and chewing motions that accompany athletic play. A loose, sliding, or repositioned guard cannot maintain the airway opening or the neuromuscular stabilization that the research on performance gains depends on.
NeuroGuard+ uses a precision dental fit developed from custom impressions, which produces a consistent jaw position throughout a game, high retention under contact, and comfort across long training sessions. That fit is what allows the appliance to actually deliver the airway and neuromuscular benefits that studies attribute to optimized jaw alignment, and it is also why athletes who try to chase the performance effect with a retail product typically conclude the effect is overstated. The performance research is on custom-fitted devices because custom-fitted devices are the only ones that hold the position long enough for the underlying physiology to take effect. A more detailed comparison of custom and boil-and-bite mouthguards is available at NG+ vs Shock Doctor, which examines the same fit-quality gap from the brain-protection angle.
NG+ Is Engineered to Deliver Performance and Protection in a Single Appliance
Performance-only mouthpieces have built a real category in the past decade — devices marketed primarily on airway opening and aerobic gains, often without an equivalent commitment to brain protection. The performance research behind those devices is legitimate, and the airway and neuromuscular pathways they target are real. The gap is that a performance-focused mouthpiece without protective engineering leaves the athlete unprotected on the dimension that actually shapes long-term health outcomes in contact sports — jaw stabilization, force dissipation to the skull, and airway management under impact rather than only at rest.
NeuroGuard+ is designed around the premise that performance and protection are not separable for an athlete in a contact or collision sport. The same precision dental fit that delivers the airway and neuromuscular performance gains also provides the jaw stabilization and force dissipation that brain protection research depends on, because both outcomes flow from the same biomechanical principle: a mandible held in an optimized, controlled position during athletic exertion. Choosing between a performance mouthpiece and a protective mouthpiece is a false trade-off when one appliance is engineered to deliver both — and for an athlete in football, hockey, lacrosse, rugby, wrestling, or combat sports, the protective dimension is not optional. A side-by-side look at how NG+ compares to category competitors across protection and performance is available at NG+ vs concussion competitors.
Key Takeaway — Jaw Alignment Is the Performance Variable Most Athletes Are Missing
The published evidence on jaw alignment and athletic performance is real but should be read at the scale the studies measured. The strongest claims supported by the peer-reviewed literature are: a 9% increase in upper airway width during mouthpiece use1, an 8.4% reduction in respiratory rate and 5.3% reduction in minute ventilation during steady-state aerobic exercise2, performance gains in lower-body power (5.8%), upper-body power (10%), flexibility (14%), and balance (4.8%) in elite athletes3, and the meta-analytic finding that custom-fitted mouthguards do not impair maximal aerobic capacity, while boil-and-bite mouthguards do4. The samples behind the first three are small (N=10, 17, and 15 respectively); the meta-analysis is the most generalizable finding. Treating any single percentage as a guaranteed individual outcome would overstate what the evidence supports.
For athletes and coaches evaluating whether jaw alignment belongs on the performance shortlist, the honest framing is: the mechanism is plausible, the published effect sizes favor custom-fit appliances over retail products, and the strongest single claim from the meta-analytic literature is that custom mouthguards preserve aerobic capacity while retail boil-and-bite products measurably reduce it. NeuroGuard+ is built around the precision dental fit that the underlying physiology depends on, and is engineered to be worn across both performance and protection contexts in contact and collision sports rather than swapped between two devices.
Frequently Asked Questions
Does a mouthguard really improve athletic performance?
The peer-reviewed evidence is stronger on what custom mouthguards don't do (impair performance) than on what they actively improve. A 2017 meta-analysis of 14 cross-over studies (Caneppele et al.) found that custom-fitted mouthguards do not significantly affect VO2max or VEmax, while stock and boil-and-bite mouthguards measurably reduce both. Individual primary studies on custom-fit appliances have measured a 9% airway-width increase (Garner & McDivitt 2009, N=10), reduced respiratory rate during steady-state exercise (Garner & Lamira 2020, N=17), and 5.8–14% improvements across power, flexibility, and balance metrics in 15 elite athletes (Haughey & Fine 2020). The samples are small and the authors themselves call for replication. The defensible claim is that custom-fit appliances are associated with measurable physiological changes that retail boil-and-bite products are not — and the mechanism (jaw stabilization, airway positioning, postural-chain effects) is plausible.
How much does jaw alignment actually affect breathing during exercise?
The most-cited primary source on this question (Garner & McDivitt 2009, N=10) measured a 9% increase in upper airway width during mouthpiece use (28.27 vs 25.93 mm, P=0.029). A separate randomized cross-over study (Garner & Lamira 2020, N=17) measured an 8.4% reduction in respiratory rate (28.35 → 25.97 BPM, p<0.01) and 5.3% reduction in minute ventilation (50.34 → 47.66 l/min, p<0.01) during steady-state aerobic exercise, with no change in oxygen consumption. A 2017 meta-analysis of 14 studies found that custom-fitted mouthguards do not significantly impair VO2max or VEmax compared to no mouthguard, while boil-and-bite mouthguards measurably reduce both (p=0.0001). The honest read is that custom mouthpieces are associated with measurable but modest changes in airway dimensions and respiratory mechanics during exercise, with the meta-analytic evidence pointing toward "do not impair" rather than "improve."
Can I get the performance benefit from a regular boil-and-bite mouthguard?
The performance research most cited in this category comes from studies of custom-fitted appliances rather than retail boil-and-bite products, and the difference is not coincidental. The performance gains depend on the jaw being held in a precise, optimized position throughout play, and retail products do not control jaw position the way custom devices do. A boil-and-bite guard may protect the teeth, but it slips, repositions, and gets removed between plays in ways that prevent the underlying airway and neuromuscular benefits from accumulating. Athletes seeking the performance research outcomes should evaluate the fit category, not just the price category.
Is the performance benefit different from the protection benefit?
The performance benefit and the brain-protection benefit run through the same biomechanical pathway — a stabilized jaw in an optimized position. The performance dimension shows up as airway opening, neuromuscular efficiency, and improved power and endurance during athletic exertion. The protection dimension shows up as force dissipation before impact reaches the skull and airway management under contact. Both outcomes require the same precision custom fit, which is why NeuroGuard+ is engineered to deliver them together rather than asking athletes to choose between a performance mouthpiece and a protective mouthpiece. For athletes in contact sports, the two jobs cannot be separated.
How long does it take to feel the performance effect?
Most athletes who try a custom jaw-alignment appliance report the breathing change within the first training session — the airway feels less restricted at high work output, and breathing feels easier in the high-intensity zones where it would otherwise feel labored. The neuromuscular and power-output effects compound more gradually as the body adapts to the new postural and breathing conditions and as the surrounding stabilizer musculature offloads the low-level work of jaw stabilization to the appliance. Endurance gains tend to be the last to appear and the most game-relevant, because they show up in the late minutes of contests when the rest of the field is already fatigued.
References
- 1. Garner DP, McDivitt E. Effects of mouthpiece use on airway openings and lactate levels in healthy college males. Compendium of Continuing Education in Dentistry. 2009 Jul-Aug;30 Spec No 2:9-13. PMID: 19774773
- 2. Garner DP, Lamira J. Respiratory outcomes with the use of a lower custom fit genioglossal-effecting oral appliance. Clinical and Experimental Dental Research. 2020;6(1):100-106. doi:10.1002/cre2.254
- 3. Haughey JP, Fine P. Effects of the lower jaw position on athletic performance of elite athletes. BMJ Open Sport & Exercise Medicine. 2020;6(1):e000886. doi:10.1136/bmjsem-2020-000886
- 4. Caneppele TMF, Borges AB, Pereira DM, et al. Mouthguard Use and Cardiopulmonary Capacity – A Systematic Review and Meta-Analysis. Sports Medicine International Open. 2017;1(5):E172-E182. doi:10.1055/s-0043-117599
