Fuel to Perform

Participating in endurance sports requires more than just overall fitness. Whether you’re training for a marathon, triathlon or anything that will require your body to work for an extended period of time, it’s crucial to take in calories throughout the event in order for your body to perform at its optimal level.

During any exercise of an hour or more, the glycogen stores in the muscles begin to deplete, and the body burns that stored fuel for energy. Consuming simple sugars and carbs is essential to maintaining those stores so the body can continue to perform.

Dr. Dana Winchester, an area nutrition counselor, stated that when you exercise for more than an hour, carbs that break down easily provide these fast-acting fuel sources, which helps propel endurance athletes. The standard recommendation is 0.7 grams of carbohydrates per kilogram of body weight per hour of exercise. That means 30-60 grams of carbs for most individuals, which are equivalent to about two or three small bananas or 32 ounces of a sports drink.

“That second hour you probably need a little more because you’re totally running out of stored sources and you need to reload entirely in order to perform,” says Dr. Winchester.

However, not all fuel sources are created equal based solely on the amount of carbohydrates. Dr. Winchester suggests staying away from foods high in proteins, fats and complex carbs, which are all going to take longer to digest and require additional energy to process.

When you replenish those glycogen stores, the quality of your workouts can remain consistent because you’re reducing muscle fatigue. You can consume this crucial nourishment in many forms – pre-packaged drinks, gels or solids, or you can make your own if you prefer real food sources, such as honey. Personal preference is fine as long as what you choose has a good balance of glucose and fructose, which can be absorbed faster than sugar alone, and a carbohydrate concentration of around 6 to 8 percent. A higher concentration may result in gastrointestinal distress for some.

How often you should consume calories varies from person to person. Some find that their bodies require refueling every 45 minutes of exercise while others may find they can go a bit longer without experiencing any fatigue. It’s important that you play around with different methods of refueling during training in order to find what works best for you so that you’re prepared come event day. Everyone’s digestive system breaks down glycogen in the food sources at different rates so you may be able to ingest all the fuel source at once, while others may find it more beneficial to take in a little bit over an extended period of time.

Always listen to your body for symptoms of both dehydration and low glycogen, which include signs such as moderate to severe fatigue and lightheadedness. Metabolism, age, gender and weight will play a role in how your body is burning your glycogen stores, so there isn’t necessarily a one-size-fits-all strategy for refueling.

It’s not necessary to consume additional calories during shorter races or exercise as glycogen stores don’t factor into performance. For shorter bursts of activity, it’s more important that you eat enough quality foods throughout the day so the body can tap into your nutrition without depleting any stores at all. •