Why Teeth Grinding Is Common Among People Who Do Heavy Strength Training

Teeth grinding (also called bruxism) is surprisingly common among heavy strength trainers and weightlifters, even if they have no dental problems in everyday life.

The main reason? Intense physical effort, combined with high mental focus and sometimes performance anxiety, causes many athletes to clench or grind their teeth during lifts,  especially at maximum or near-maximum loads.

This response is both unconscious and physical: clenching helps stabilize the jaw and neck, but over time, repeated grinding can lead to jaw pain, cracked teeth, and other dental issues.

Add in pre-existing stress, stimulant use, or nighttime habits, and the problem becomes even more likely.

Why Does This Happen? The Science of Clenching and Lifting

1. Physical Effort and Neuromuscular Response

When you push or pull a heavy load, your body naturally recruits every muscle group needed for stability, including your jaw. Clenching your teeth creates a fixed anchor point for the muscles of your head and neck, helping stabilize your upper body and transfer force more efficiently.

This is especially pronounced in big compound lifts like deadlifts, squats, or heavy bench presses. Research published in the Journal of Oral Rehabilitation has shown that athletes can increase maximum force output simply by clenching their jaw during effort, which partially explains why so many do it instinctively.

2. Mental Focus, Stress, and “Game Face”

Strength training—especially when pushing personal bests—requires intense concentration and, for many lifters, a bit of performance anxiety. The face and jaw tend to tense up along with the rest of the body as you brace yourself for a difficult lift.

This is part of the “fight or flight” stress response: the brain triggers widespread muscle contraction, and the jaw is often one of the first places to show tension. Over time, this can become a habit, leading to teeth grinding even outside the gym, especially for people prone to stress or perfectionism.

3. Stimulant Use and Pre-Workout Supplements

Studies have found that high caffeine intake is associated with a higher incidence of teeth grinding, and the effect is even more pronounced for those already experiencing gym-related jaw clenching.

4. Night-Time Bruxism and Carryover from Daytime Habits

For some lifters, the jaw tension and teeth grinding that start during heavy lifting sessions don’t end when the workout is over. If you routinely clench your teeth during squats or deadlifts, you may unconsciously carry that habit into sleep, especially during times of heightened stress or after intense training blocks.

Dentists often report that athletes who grind their teeth at night have developed the habit as a “carryover” from their high-intensity training routine.

How Common Is It? (Stats and Reality)

While precise numbers vary, studies estimate that 20–35% of athletes who do regular strength training report some level of jaw clenching or teeth grinding during workouts. Among competitive powerlifters and Olympic lifters, the rate is likely even higher.

Some dental clinics in cities with large lifting communities report that as many as 1 in 4 new adult patients with bruxism are recreational or competitive strength athletes.

While exact statistics depend on the population studied, multiple surveys and dental studies suggest that teeth grinding and jaw clenching are far from rare among people who strength train. According to published research, roughly 20–35% of recreational lifters and gym-goers say they notice themselves clenching or grinding their teeth during heavy sets.

This self-reported number lines up with what many personal trainers and dentists observe in their clients and patients: jaw tension is simply part of how some people channel effort and focus in the gym.

The numbers get even more striking in the world of competitive lifting. Among Olympic weightlifters, powerlifters, and strongman athletes—where max effort lifts and extreme mental focus are the norm—the rate of bruxism can approach 40% or higher.

In these communities, it’s not uncommon to hear about cracked dental fillings, chipped molars, or jaw soreness after a competition or a high-intensity training block. Even coaches sometimes remind athletes to “watch your jaw” or recommend mouthguards for big lifts.

What about outside formal research? Anecdotally, urban dental clinics in neighborhoods near large gyms or lifting clubs report a steady stream of clients with tooth wear, jaw pain, or unexplained dental fractures—many of whom are serious about strength training.

@dr.sara_alhammadi Heavy lifters, this one’s for you! 🏋️‍♂️ Ever find yourself clenching your teeth during a tough set? I’ve been there, and it’s risky business for your teeth. Clenching can cause micro-cracks, which may eventually lead to a tooth breaking in half! 😬 Just ask the powerlifter who ended up needing an implant after cracking a tooth mid-lift. So here’s a pro tip: always use a sports guard when lifting heavy. Protect your smile as you strengthen your body! 🦷 #LiftSafe #GymTips #dentalcare ♬ original sound – Dr. Sara Alhammadi

Some clinics have estimated that one in four new adult patients with bruxism are recreational or competitive lifters. Dentists may notice “wear facets” (flat spots from grinding), tiny enamel cracks, or TMJ soreness during routine exams, prompting them to ask about training routines or mouthguard use.

While these numbers are striking, many people are unaware of the dental risks associated with heavy strength training until they experience tooth sensitivity, jaw pain, or an unexpected dental bill.

In fact, for those training in countries with national healthcare or special medical savings plans, it’s worth noting that programs like Medisave for dental in Singapore may help offset the cost of dental treatments and preventive mouthguards.

If you’re a frequent lifter noticing symptoms, ask your dentist about using health savings or Medisave funds for dental checkups or custom guards—small steps that can save you both discomfort and expenses down the road.

Practical Impact: What Are the Risks?

What Can You Do About It?

If you recognize this pattern in yourself or your clients, there are several ways to minimize the impact:

• Be aware of your jaw: Check in before and during each set—remind yourself to relax your face and jaw as much as possible, except when needed for bracing.
• Try a mouthguard: Many athletes wear soft or custom-fit mouthguards during heavy lifts to cushion the teeth and reduce risk.
• Manage stimulants: Limit caffeine and pre-workout intake, especially later in the day.
• Destress after training: Practices like stretching, deep breathing, or even meditation can help reduce post-workout tension that leads to nighttime grinding.
• Consult a dentist: If you notice tooth pain, jaw soreness, or other symptoms, a dentist can help fit a night guard or check for signs of damage.

Final Thoughts

Teeth grinding is more than just a dental nuisance for heavy lifters—it’s a real side effect of high effort, intense focus, and the pressure to perform.

By understanding why it happens and taking a few proactive steps, you can protect your teeth, jaw, and overall health, making sure your strength gains don’t come at the expense of your smile.

If you’re dealing with this issue or have questions about jaw health and training, just ask—there’s plenty you can do to lift strong and keep your teeth safe.