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The "Tooth" About Endurance Training

By: Kandice Swarthout

Have you ever considered how endurance training can affect your oral health? Your teeth and gums are deeply integrated with the rest of your body, so it's more important than ever to keep them clean and healthy. 

In all my years as a dental hygienist and a half marathon runner, I hadn't put much thought into my oral health while training. Recently, a colleague posed the question: “Can endurance training change the saliva, creating an unhealthy oral environment leading to cavities?”  Her question was based in 20 years of clinical experience seeing several marathon runners and triathletes as patients. This sparked my curiosity, so I partnered with two dental hygienists to uncover the answer. This is what we found:


Salivary Alpha Amylase

Saliva plays a critical role in dental plaque formation and in the health of teeth. Plaque is a complex bacteria that forms on teeth and must be removed daily to prevent cavities and gum disease. Salivary alpha amylase is a key biochemical marker in the saliva. It is one of the most abundant components in human saliva, and has at least three functions. It plays a role in carbohydrate digestion, binds with high affinity to a selected group of oral bacteria, and binds to teeth as a constituent of the proteins that cover the tooth surface. Salivary alpha amylase is connected to an increase of norepinephrine and epinephrine in relation to stress. Physical stress such as endurance training increases the amount of salivary alpha amylase found in saliva. 

Through a series of biological events, the increase in salivary alpha amylase during physical training increases dry mouth, promotes dental enamel erosion (the loss of tooth enamel through chemical means) and increases the risk for cavities. Studies show that saliva can be reduced in the mouth by 64% and salivary alpha amylase can increase by 50% during endurance exercise. Any time saliva is reduced, the risk of erosion and cavities increases. Combine dry mouth with the sugar in sports drinks and increased alpha amylase… and you might be scheduling your next dental filling.

Pre-workout and Sports Drinks

Pre-workout and sports drinks are recognized in the dental profession as enemy number one when it comes to erosion and decay. Even a “sugar-free” beverage can be highly acidic and directly weakens the tooth enamel through chemical erosion. Dental enamel begins to dissolve at a pH of 5.5. Most sports drinks have a pH of below 5.5. Bathing the teeth in highly acidic drinks over a period of time (sipping on a sports drink during a 1-2 hour training session) in combination with dry mouth, severely increases the level of dental erosion. Without the “washing away” and neutralizing effects of saliva, the mouth becomes an optimum environment for enamel breakdown.

Are You Carb Loading? 

Now consider the food and drink choices offered at the end of a race: oranges, fruit juice, sports drinks, and sometimes beer - if you’re lucky. You just spent the last 2-4 hours increasing your salivary alpha amylase, decreasing your saliva volume, and sipping a highly acidic or carbohydrate based beverage. As your body is recovering, you peel and eat an orange to replenish energy and mosey on over to the beer tent to use that ticket. Your body thanks you, but your teeth are screaming “STOP!” 

This practice doesn’t occur only on race day, but also on training days. Personally, if I run more than 8 miles in one session, I plow through some serious carbohydrates the rest of the day. My body begs for it. Naturally, I listen to my body’s needs and replenish accordingly. Most athletes spend considerable amounts of time planning the best eating schedules and food choices for optimum performance without considering the detriment to the dental environment. This is an important thing to ponder because almost every dental issue is connected to the overall health of the body. In addition, if you do not have healthy teeth for chewing, you are not likely to consume the healthy diet required for fitness and wellness.

Now, don’t let me rain on your runner’s high parade. Refrain from dashing to the pantry to toss out all of your goo packets and pre-workout mixes. There is a silver lining in this tale of the athlete’s tooth. There are simple and attainable steps that every endurance athlete can take to reduce the risks or erosion and decay.


Take Action:


  • Rinse with water frequently during training. A small sip of water that is swished and either spit out or swallowed can wash away the acid and sugar from intra or pre-workout beverages.

  • Consider reducing sugary and acidic foods and beverages during non-training hours. If eliminating certain beverages is not on your list of desires, try drinking through a straw. This will bypass the teeth.

  • See your dental hygienist every 3-6 months for routine preventive care. She/he can remove the bacteria that contributes to decay and apply a professional fluoride varnish treatment that protects the teeth for months beyond the application.

  • Substitute sugary acidic sports drinks for coconut water which has a pH of 6.10-7.0, making it a much safer choice for dental enamel. Another enamel friendly option is a sugar-free carbohydrate supplement mixed with water. An example is Karbolyn that can be found at a variety of health supplement retailers.

  • Increase home fluoride use through toothpaste and rinses. A variety of over-the-counter products are available or you could talk to your dental hygienist about prescription options.

  • Chew xylitol gum during and after training. Xylitol is a natural sugar that defends against the bacteria that causes cavities.

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About The Author

Kandice Swarthout (far left) M.S., RDH, LPC is a Registered Dental Hygienist and certified Strong First kettlebell instructor. She is a full time dental hygiene professor in Dallas, Texas. Swarthout, along with her colleagues Keri Lilley (center) and Danielle Dotson (far right) contributed to this piece due to their passion for fitness and overall oral health awareness. 

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