Health Center: Sports Nutrition Basics
Sports Nutrition Basics
Fuel used during exercise
For most exercise, your body uses a combination of carbohydrate and fat for fuel. This is especially true for longer lasting events (cross-country). Quick bursts of energy require primarily carbohydrate for fuel (short distance running/track). Many sports are a combination of endurance and quick bursts of speed (soccer, basketball). The longer the exercise, the higher percentage of fat that is burned; however, if there is not enough carb to use as fuel, then fat is not able to be used efficiently and your performance will suffer.
If you are exercising longer than 60 minutes, external sources of carb (fruit, Gatorade or other sports drinks, bars, etc) need to be ingested during the event. Take the opportunity to fuel up during breaks, but keep amounts small enough that they don’t impact your performance.
Inconsistency with nutrition and hydration can affect both training and performance during events. Fueling your body before, during and after training is important.
Fueling for Optimal Performance
Most studies agree that a high carb diet (55-60% of total calories) is best for athletic performance. A moderate amount of fat (20-30%) is important since fat is a major fuel source. Protein is vital for maintaining and building muscle mass, but there is no established benefit to eating more than 15% of calories from protein. Always be sure you are well hydrated before exercise.
It’s best to try out different strategies for eating during practice (ie. varying the timing of meals and snacks), so you can determine the way your body works best. Experimenting during games or competition can obviously have unpredictable results. Eat every 3-5 hours to keep metabolism high and to maintain glycogen (stored carbohydrate used for energy) stores.
Most people feel and perform best if they eat within 1-3 hours before exercising. If you’re eating only 1 hour before, keep it light: granola bar or ½ sandwich or yogurt is a good choice). Avoid eating sweets and sugary foods before exercising; these will make you feel sluggish and low-energy.
If your workouts/games/events are longer than 60 minutes, include some carb-containing food or drink during the workout. Most people tolerate fluids better, and sports are formulated to give a good combination of fluid, carb, and electrolytes for replacement. Alternating sports drinks and water, or using sports drinks diluted with water, is a good way to keep you hydrated. Ideally, drink 4-8 ounces every 15-20 minutes during your workout or game.
The body is most receptive to replacing glycogen 15-30 minutes after exercise, so always consume carb containing foods or fluids during this window of time (fruit, nutrition bar, glass of milk or yogurt, etc). Waiting an hour or more to eat will mean your performance will suffer the following day, and you will likely feel fatigued. In addition, eat a substantial snack or meal within 2 hours after exercise. This will help recovery significantly, and will refuel your glycogen stores for the next day or next event. A high carb meal or snack with protein is your best choice: sandwich with juice or milk; a bagel or banana with peanut butter; yogurt and fruit; or an entire meal such as chicken, pasta or rice, and vegetables. Nutrition/sports bars can be helpful when other food is not available, but should not be used to replace meals.
Only carbs will refuel your muscles for the next workout, so be sure carbs are part of your post-workout meals. Additionally, taking 1-2 days/week off from workouts allows your muscles to recover and glycogen stores to be replenished.
Hydration is critical to performance, which can suffer with only 1-2% of loss of body water. Drinking water frequently is the best way to stay hydrated. Monitor your urine color on a daily basis to be sure you’re staying hydrated. Urine should be clear to light yellow. If you take vitamin supplements, your urine will likely be bright yellow for the next few hours due to the effect of B vitamins. Don’t be alarmed by this, but check your urine at other times for color.
Include at least 8-10 cups water or other non-caffeinated fluid daily, and add to this to replace how much you sweat. This varies by person, time of year and type of exercise. Monitoring your urine color will help you figure out how much water you need.
© Valerie Edwards, MS, RD, LD