Pre- and Post-exercise Nutrition
What we eat before and after our workouts is important to helping us reach our health goals. Fuelling properly before a workout allows us to put in our best effort to get the most out of our workout, while eating afterward helps to kick-start the recovery process so that we can do it all over again.
When we exercise, the immediate source of fuel for the working muscle is found right at the muscle site. Depending on your gender and body weight, you may have in the neighborhood of 1,400 calories of carbohydrate in the form of glycogen available in the muscle, right now. There is an additional 80 calories of carbohydrate floating in the blood as blood sugar, and approximately 320 calories of carbohydrate stored in the liver also as glycogen – all pretty immediate sources of fuel. However, just because we have all of this available for use doesn’t mean that you can ignore hunger pangs and lightheadedness as you head into the gym for the workout. Nor does it mean that you need to eat a full meal before you hit the gym. The situation is dependent on a variety of factors:
- The time lapsed since your last meal
- The type of exercise you intend to engage in
- The intensity of the workout ahead of you
- The time expected for the workout
- The goal of the exercise session
If it has been more than four hours since your last meal, then a snack within an hour or two of your exercise session may be necessary. This is particularly important if you expect your exercise to be very intense. When blood sugar takes a dip, we can get a feeling of weakness or shakiness. This is never good heading into a workout because it generally affects how much oomph we have for the workout session.
The ideal pre-exercise snack or meal should:
- Be high in carbohydrates, like grains and fruit, to provide the energy necessary for the workout.
- Contain a moderate amount of protein to provide extra energy and to prevent a feeling of hunger during the workout/competition.
- Be low in fat and fibre as they take longer to digest – this will help to minimize cramps during the workout.
Some examples are of pre-exercise snacks are:
- A bowl of cereal with milk or yogurt
- Half of a peanut butter and banana sandwich
- A protein bar or other meal replacement bar
- Yogurt and fruit
- A liquid meal replacement like Ensure or Boost
- A soy or milk and fruit smoothie
Carbohydrate-rich meals, such as whole grain pasta with tomato sauce and some lean meat, can be eaten about 3 – 4 hours before exercise, based on what you can tolerate. You should also remember to drink 1-2 cups of water about four hours before your workout so that your body is hydrated, while giving you enough time to go the bathroom beforehand.
If you are planning to do a low-intensity activity (60 – 75% maximum heart rate) for up to two hours, like walking, and your primary goal is fat burning, then it is not necessary to fuel with carbohydrates as you should probably have enough stored carbohydrates to get through your workout. Eating before a low-intensity activity will encourage your body to burn this new source of energy instead of using your energy stores and helping you burn fat.
Part 3: How to recover after your wok out
During exercise, carbohydrate stores are depleted to some degree, muscle tissue experiences some damage, and some by-products are produced. Recovery and improvement begins when the exercise ends. Optimal nutrition after exercise may be critical, depending upon the type, intensity, and time spent exercising.
If you have had a ‘tank draining’ experience in your exercise session through high intensity or long duration, you are a candidate for ensuring that you get both carbohydrate and protein in either a 3:1 or 4:1 ratio within 30 minutes of finishing your exercise session. This balance helps to put the carbs back into the muscle and can help to start the recovery process. If you have done a light workout and are intending to get to a meal within a couple of hours, then you are okay to focus on re-hydrating with water, and it’s not as critical to focus on re-fuelling after the session. In this case, drinking a box of juice and additional water would suffice.
Some examples of post-exercise snacks are:
- Half of a peanut butter sandwich with chocolate milk
- Fruit juice and cereal bar
- Liquid meal replacement (like Ensure or Boost) with a banana
- Yogurt sweetened with a spoonful of honey and fruit
- A protein bar or other meal replacement bar
Your post-exercise meal can be the same as any regular meal – 1-2 servings of grain products or other starchy foods (i.e. pasta, rice, potatoes), a serving of meat and alternatives (i.e. 3 oz. of meat, fish, or poultry, or ¾ cup of tofu or legumes), lots of vegetables and/or fruit, and ample fluids.