Wales’ Jamie Roberts uses the UA Mouthpiece in training

Gumshields have long been worn by players to protect their teeth on the field, but how about one that could also increase your strength, endurance and reaction times as well? Sounds too good to be true – well, it isn’t, writes Sarah Mockford.

The Performance Mouthguard

The key is in the jaw. Clenching your teeth is a natural reaction when exerting yourself, but doing so compresses your temporomandibular joint (TMJ) – jaw joint – and triggers the release of cortisol and other hormones, which can lead to stress and fatigue when overproduced. It also narrows your airway, so there’s less oxygen in your body to prevent lactic acid build-up.

For centuries people have tried to address this glitch in the body – ancient warriors biting on leather straps, for example – but how does this help?

Preventing teeth from clenching fully by shifting the jaw down and forward not only relieves pressure on the TMJ, thus reducing cortisol production, but also widens the airway. Now, after 15 years of research, scientists have designed mouthpieces that allow sportspeople to improve their performance.

Under Armour have used Bite Tech’s patented wedge to produce a range of mouthwear to realign the jaw. The UA Performance Mouthpiece (above) sits over the bottom teeth and is designed to be used in the gym while, for your top teeth, the Performance Mouthguard (below) not only provides performance benefits but helps to protect your teeth.

The results of scientific studies, including one at the Military College of South Carolina, into the benefits of wearing the mouthpieces are hard to get your head round. Strength increases by up to 20%, endurance rises by an average of 17% while reaction times and cortisol levels are cut in half (both 49% decrease) and lactic acid is down by 25% after 30 minutes of exercise. All from a piece of plastic!

The Performance mouthpiece

It’s easy to be dubious about these claims, but rugby’s pros have been won over. Wales centre Jamie Roberts says: “When running or doing weights you tend to clench your jaw, so I use the lower piece in training.
“I feel I can breathe easier with it in as the airflow is better and little one per centers can help improve your game.”

There are two types of UA Performance Mouthwear. You can have a dentist take impressions of your teeth or buy one of the DIY Boil ‘n’ Bite range, which will be available from early June priced £59.99. For info, see

What it does…?

  • Moves the jaw down and forward
  • Reduces pressure on the TMJ (jaw joint)
  • Opens up the airway

The Benefits…

  • Increases strength
  • Increases endurance
  • Speeds up reactions
  • Decreases stress
  • Decreases lactic acid

This article appeared in the June 2011 issue of Rugby World Magazine.

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