Athletes often wear a mouthpiece to prevent breaking their teeth or biting their tongues. They might also want to wear one to reduce stress, hasten recovery and improve performance.
Researchers at two universities in South Carolina have discovered the custom-fit ArmourBite mouthpiece manufactured by Bite Tech can decrease the level of cortisol in the bloodstream after strenuous exercise. The reduction indicates the body is experiencing less stress after a workout and may recover faster.
The researchers don’t know why the mouthpiece does this, but they think it has something to do with the shape. The wedge-shaped mouthpiece rests on the lower jaw, moving the jaw down and slightly forward when the teeth are clenched.
"Something has to be happening with that change in position that causes hormonal changes,” said Wesley D. Dudgeon, an assistant professor and director of the Exercise Science Graduate Program at the Citadel. “You can't fake a stress hormone.”
Dudgeon and his colleagues embarked on the study because there hasn't much inquiry into how mouthpieces might affect performance. Most research is focused on how they protect the mouth. It should be noted that BiteTech helped finance the research by the Citadel and College of Charleston, though it insists it did not meddle in the study.
“Much of the work has been peer reviewed, and we do not direct or tell them what to research,” said Mark Mastalir, the company’s chief market officer.
The study builds upon previous research by members of Dudgeon’s team that found lower-jaw mouthpieces help increase oxygen consumption and the amount of carbon dioxide exhaled while running. Earlier work also revealed that football players who wore the mouthpieces had lower levels of cortisol in their saliva following a workout.
In conducting this study, 13 college-age men wore AmourBites while completing 10 repetitions of back squats, resting two minutes between sets. They returned seven days later to perform the same routine without the guards.
The researchers collected blood samples immediately before and after each workout, and at 30-, 60- and 120-minute intervals afterward. There were no differences in cortisol levels before the workouts, but those who wore mouthpieces had lower levels of the stuff during their workouts and 30 minutes afterward. There was no difference at the 60- and 120-minute intervals.
Why track cortisol? Cortisol is a necessary catabolic hormone for exercise, as it breaks down nutrients to provide fuel. But post-exercise, too much cortisol can impede recovery, making you more sore. Decreasing cortisol levels could benefit athletes who train daily.
Since publishing their findings in October in Journal of Strength and Conditioning Research, the researchers have discovered the same 13 test subjects also had a lower blood lactate level while wearing the mouthpiece. Blood lactate is the byproduct of glycolosis (where we get our energy during higher-intensity activities) and a marker of fatigue. When blood lactate levels are lower, you can exercise at a higher intensity before becoming fatigued.
Dudgeon says more research is needed to understand why small adjustments in lower-jaw position might have so great an impact on training and recovery, and what it means for athletes.
"If lactate levels are lower you can train harder. If cortisol is lower you aren't as sore the next day, so you can train harder and recover more quickly,” Dudgeon said. “This could lead to an allover improved athlete," he said.
