Sheila's Nutrition Digest Vol 18: What should I eat before I workout?
By: Sheila Kealey (2010/01/08)
Here are some tips to help you do it right. . .
Carbohydrate-rich foods or beverages are your best bet before exercise. These foods tend to digest well and quickly, so you won’t have as much in your gut while you’re exercising. Carbohydrates are an athlete’s main source of energy, stored in muscles as glycogen, or circulating in your bloodstream as glucose.
What not to eat: Limit heavy proteins and fatty foods before exercising (meats, greasy foods, cheeses) since they take longer to digest. Spicy foods and very high fiber foods are also best to avoid (whole grain breads, cereals, and most fruits are probably fine - and preferable to refined foods - for most, but best to avoid gas-producing foods like beans/legumes and cabbage).
Won’t carbohydrates cause my blood sugar to crash and make me tired? While it is true that carbohydrates will increase insulin and blood sugar, followed by a decrease in blood sugar at the beginning of exercise, studies have shown that this dip in blood sugar is short lived and doesn’t affect overall energy levels. The performance benefits of ingesting carbohydrates far outweigh the small and temporary decrease in blood sugar. However, some individuals are more sensitive than others to increases in insulin. These individuals should try consuming carbohydrates with a lower glycemic index (i.e., slower digesting carbohydrates that cause less of an increase in blood sugar). Also, consuming carbohydrates (e.g., sports drink) during activity can offset drops in blood glucose.
Protein. Research suggests that including a small amount of protein in your pre-workout meal can help support muscle repair and growth. Good choices for most athletes that are well-tolerated before exercise include low-fat or non-fat dairy products like yogurt and milk, nut butters, or eggs. Decrease the protein content of your meal in favour of carbohydrates as you get closer to your workout time.
Fluids. Start your exercise
with optimal fluid levels. Water, milk, soymilk, or unsweetened fruit
juices are good options. Liquid/blender meals (e.g., fruit smoothies)
can cover fluid and carbohydrate needs, are convenient, and tend to
Here’s a scenario for timing pre-workout meals and snacks.
- 3-4 hours before training: eat your last big meal– which should favour carbohydrates but also include protein and fat.
- Within 2 hours of training: eat a carbohydrate-rich snack and/or beverage.
- 60 minutes to start of workout – drink sports drink or water and a very light snack
When this timing isn’t practical, pay more attention to your food choices and portions. Generally the closer you are to your workout time, the fewer calories you should consume. Stick to higher carbohydrate foods or liquids that you tolerate well.
Morning Workout: While you sleep, liver glycogen can deplete by as much as 80 percent. Eating something before morning workouts will help stave off fatigue - even a light snack will help. Some people can tolerate a decent-sized breakfast with no ill effects. If you don’t have time, or you can’t stomach food before early workouts, be sure you consume something like a sports drink during exercise to provide the fuel and liquids you need.
Evening Workout: If your last meal was at noon, you’ll need to eat before heading out to exercise. Depending on the intensity and time of the workout, a full meal might not be possible. Be sure to consume a healthy carbohydrate-based snack, or a smaller portion of more traditional supper foods that you know sit well. If possible, you might want to change your meal time to benefit your workout. For example, if your evening workout is at 6:30, try to eat lunch at 2:30, have a light snack at 4:30, and sports drink, diluted juice, or water and another light snack within an hour of your workout.
These types of foods are popular with many athletes and suitable to consume within 2 hours of a workout.
- Peanut butter and banana sandwich on whole grain bread or bagel
- Banana topped with 1 tbsp. nut/seed butter
- 1 cup breakfast cereal topped with lowfat milk of soymilk and ½ cup fruit
- Fruit smoothie: Blend 1 cup nonfat milk, 1
banana, ½ cup frozen strawberries or blueberries (+1 tbsp. protein powder-optional)
- 1 cup nonfat vanilla yogurt with 1 cup chopped fruit or berries
- Pita with hummus, vegetable juice
- Whole grain bagel or bread topped with tomato slices and low-fat cheese
Intense exercise diverts blood flow from the stomach to the working muscles, which can interfere with digestion. This can lead to cramping, bloating, and nausea in some individuals. If you suffer GI problems during activity, consider the following:
- Choose your pre-workout foods carefully, limiting high fiber foods, spicy foods, heavy proteins, and fatty foods.
- Allow enough time between eating and exercising – experiment with different time windows
- Eat familiar foods that you know won’t upset your stomach (e.g., low-fiber cereals with lowfat milk, applesauce, low-fat yogurt, bread or bagels and jam, or bananas)
- Stick to small portions of easily digested carbohydrates like breads, pasta, and rice
- Liquid meals are generally well tolerated and empty the gut quicker than solid foods (e.g., blend milk, banana, other fruit).
- Sports drinks are also generally well tolerated, especially in the hour before training since they exit into the small intestine sooner and are absorbed quicker.
Even with practiced eating routines, pre-competition nerves can wreak havoc on the heartiest of stomachs. In addition, high intensity efforts often require modifying your pre-exercise diet. Generally, follow the guidelines above for “tummy troubles,” and when in doubt eat less, and opt for liquid calories.
Finding what works for you
Use these pre-workout eating strategies as a guide, but keep in mind that food preferences and tolerances vary quite a bit among individuals. Also, what you can eat may depend on the activity (e.g., cyclists can generally tolerate more food in their stomachs than runners). Intensity has a great influence too: you can get away with eating more food and a variety of foods before an easy workout compared to a time trial or intervals. Try out different foods, portions, and timing in training, and find out what works best for you.
Also, beyond your pre-workout foods, remember that your overall diet is critical to good health. Although engineered products (e.g., sports drinks, bars, gels) are convenient and well-formulated forms of fuel for exercise, they are mostly refined carbohydrates and not the foundation of a good diet. Aim for an overall diet that includes plenty of vegetables, fruits, whole grains, legumes, and healthy fats. These foods are important for good health, will help fight disease, and boost your immune system.
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