Success in endurance activity is a result of a multitude of genetic and physiological factors. While many of these factors are out of our control, one major player in the success of the endurance athlete is fluid and nutrient intake in and around training and competition. Therefore in this article I'll describe a few strategies for eating and drinking for a big race.
During endurance activity the body uses muscle glycogen, blood glucose, muscle triglycerides and free fatty acids from adipose tissue to provide the ATP to fuel performance. The relative ratio of these substrates utilized is dependent on exercise intensity and exercise duration as well as availability of each substrate. As exercise intensity increases during an endurance bout, more carbohydrates are used.
However, since carbohydrates are limited in supply, as the exercise continues (and the body's carbohydrate stores diminish) more stored fats are used. Unfortunately the metabolism of fat is less metabolically efficient; therefore when carbohydrates become limited, exercise intensity must diminish. Since the body typically contains enough stored fat to fuel several marathons, the focus of eating for endurance activity should be on the carbohydrate content of the diet.
Before exercise
The size and timing of a meal or snack before an intense workout depends on your individ
ual needs. The longer
the time between eating and activity the more you might be able to eat.
Approximately 2 –
4 hours before an endurance event,drink plenty of fluids and try to eat a meal high in
carbohydrates (e.g. grain products, fruits and vegetabl
es), relatively low in protein (small servings of choices such
as chicken, beans, or hummus), and fibre and low in fat.This may help to:
•
boost energy levels
•
prevent hunger
•
keep you hydrated
•
extend your time to exhaustion
Some people experience an upset stomach if they eat a meal before endurance activity. A liquid snack such as a
sports drink or smoothie is a good alternative.
Carbohydrate
-rich snack examples include some sport bars, fruit, cereal with milk, lentils, bagels, pasta, yogurt,
and homemade granola bars.
"Carbohydrate
-loading" (for competitive activities that last longer than 90 minutes) has been found to build extra
carbohydrate energy stores in the body (as muscle and liver glycogen). However, it may not offer additional
benefits to performance if you follow a high
-carbohydrate diet or eat a carbohydrate rich snack before and/or during exercise.
Option 1: 2-3 hours before exercise
This far in advance of your workout, have a mixed meal and a low-calorie beverage like water.
If you’re a man, here’s what your meal might look like:
If you’re a woman, here’s what your meal might look like:
During Exercise
During intense exercise that lasts longer than one hour, eating carbohydrate might help extend time to exhaustion
and may improve performance in some activities such as sprints and agility drills.
Approximately 30 –
70 g of carbohydrates per hour (such as in the form of a sports drink), in small amounts every
15 to 20 minutes, can improve exercise performance.
For activities lasting longer than an hour or in extreme heat, sports drinks provide hydration as well as
carbohydrate.
It is important that you drink enough during and after exercise to replace the fluid you lose in sweat.
To find out how much you typically sweat during training or competition weigh yourself before and after exercise.
Factor in how much you drank. The difference will be sweat losses.
After exercise
Muscles need protein for recovery and growth, and the best time to deliver protein appears to be right after exercise. Providing high-quality protein after exercise gives your muscles the fuel and the building blocks needed for both repair and for growth.
Protein shakes and powders carry a certain allure, but your muscles don’t care if the protein comes from a hard-boiled egg, glass of chocolate milk or whey protein shake. Whatever you choose, more isn’t better -- only 10 to 20 grams of protein is needed to provide amino acids (the building blocks of protein) to muscles.
With so many sports drinks, bars, and more to choose from, how do you make the best choices?
A good sports drink contains 14-15 grams of carbohydrate in 8 ounces. It should also contain about 110 milligrams of sodium and 30 milligrams of potassium in the same volume. But if you are exercising to lose weight, stick to water or a "lighter" version of sports drinks with fewer carbs and calories.
Look for energy bars that contain about 5 grams of protein, with some carbohydrate (preferably with more naturally occurring sugars) and very little fat. Many energy bars are just glorified, expensive candy bars, so remember that "energy" means calories and watch out for high-calorie bars. They are helpful for athletes on the go, so if you can't eat before a long tennis match, an energy bar can help.
Choose protein powders made from whey protein or milk proteins (milk protein contains two types of proteins, both whey and casein). Use them within 30 minutes after exercising to provide needed amino acids to muscles. For weight gain, use a protein drink as an evening snack.
What are gels and what role do they play in fitness performance?
Gels are good for endurance athletes but are not needed by the recreational athlete. Gels are concentrated forms of carbohydrate and can help long-distance cyclists and runners get some quick fuel during exercise. Since they are so concentrated, they should be washed down with water to avoid stomach upset.
How do you know if you're getting the right amount of calories and nutrients?
To get an accurate assessment of your calorie and nutrient needs, see a registered dietitian or a certified specialist in sports dietetics. For a quick, but less accurate assessment, try www.mypyramid.org to track your energy needs and your exercise [or use WebMD's Food and Fitness Planner].
Are there any benefits to exercising in the morning vs. at night?
The best advice is to just do it. There are no benefits to either time; it's simply a matter of personal choice. Some people prefer morning exercise and the satisfaction that it is done without worrying that it will be squeezed out by their daily routine. Others prefer to exercise later in the day, when muscles are warmed up, and it helps revive them for the evening. The only caution may be not to exercise close to bedtime. Some experts believe that the increase in body temperature and metabolism may interfere with sleep. Exercise is great for sleep, and the National Sleep Foundation's tip for sleep hygiene suggests that in those without a sleep disorder exercise at any time is good for sleep.
Is carbo loading a useful strategy for long-distance athletes?
Carbo loading, or stocking up on carbohydrates before a sporting event, has gone out of favor with most athletes. Eating adequate carbohydrates during training provides muscles with all the glycogen (the storage form of carbohydrate) that they need.
Athletes who exercise for longer than two hours usually consume some form of carbohydrate during exercise (sports drinks, carbohydrate gels, or energy bars) to provide additional fuel. Carbohydrate loading (also called "muscle glycogen supercompensation") should only be considered for those performing very hard, continuous exercise that lasts for 90 minutes or more, and should be done under the supervision of a sports dietitian.
What are good, healthy snacks for kids during sport activities or practice?
When it is your turn to bring the snacks, keep it simple and healthy. Let’s face it; young kids don’t burn a lot of calories in a recreational weekly soccer game, so provide healthy snacks in small quantities. Orange or apple slices; peanut butter sandwiches cut into quarters; string cheese and whole-grain crackers; and trail mix made with whole-grain cereal, nuts, and dried fruit; along with fruit juice, are good choices.
Can you lose weight without having to exercise?
Yes, you can, but the best strategy is a combination of cutting calories and exercising. Exercise has other benefits that can help with weight loss. It improves mood and self-esteem, as well as reduces risk for heart disease, high blood pressure, and diabetes.
Exercise burns fewer calories than you might think. Walking 1 mile burns about 100 calories, and 1 pound of body fat is a storage depot for 3,500 calories. You’d have to walk 35 miles to lose 1 pound of fat.
What changes should you make to your diet if your goal is to lose fat?
If your goal is to lose weight and target fat, you need to follow the same kind of healthy diet as above, but be sure you get enough calories to fuel your physical activity. Cut back on refined, sugar-rich foods and beverages and high-fat and fried foods, and scale back your portions to gradually lose body fat. A combination of exercise and a calorie-controlled diet will be the most effective way to promote fat loss.