By: Dr. Maureen Kennedy
Q: I am ready to get into shape this year. I know I need to eat less to lose weight but how do I eat properly so that I have the energy to exercise?
A: The start of a new year is when many people want to make a lifestyle change. Just thinking about how to improve your health is a step in the right direction. While some people try various fad diets that remove certain types of foods, few think about how to eat to maximize their ability to exercise and lose weight. Food supplies you with the energy you need to do physical activity. The more physically active you are, the more calories you will need for your energy supply. If weight loss is your goal, more activity with a decrease in calories will result in a loss of body fat and some weight. It is important to realize that what you eat and when you eat can impact on how energetic or tired you feel for your physical activity.
What are the energy foods?
We can actually obtain energy from all the food we eat, whether it is fat, protein or carbohydrate. However, our bodies prefer to use carbohydrate as the prime energy source. Exercise of a longer duration will also use fat for energy. Eating complex carbohydrates (breads, pasta, potatoes) for energy sounds familiar to most of us. Our body uses the carbohydrate as an energy source by breaking the complex carbohydrate down into simple sugar (glucose). When we are not active, some of the complex carbohydrate will be stored, primarily in the liver and muscles, ready to be broken down into simple sugar when we need it to do so. Any excess carbohydrate not used for energy storage will be converted to fat.
When you eat your carbohydrate is also very important. If you are going to exercise in less than two hours, a large amount of complex carbohydrate is not what you should be eating. This is definitely not the time to eat a plate of pasta. Eating recommendations for the average person include a diet consisting of about 50-60 per cent carbohydrate, 15-20 per cent protein and 25-30 per cent from fat. Unless you are doing frequent and vigorous physical activity, do not eat greater than recommended amounts of carbohydrate, as this will convert to fat.
Can you eat before physical activity?
Contrary to warnings that you should never eat just before a workout, you can actually eat or drink simple carbohydrate or a small amount of a complex carbohydrate. A piece of fruit, fruit juice or a slice of bread are examples of a pre-activity snack. Don't forget to drink some water before your activity. One cup of water about 15 minutes pre-activity is a good idea. If you have a vigorous workout, eating larger amounts of carbohydrate with a small amount of protein after exercise is a good way to help replenish the carbohydrate stores your body used for activity. A bagel with some peanut butter or a cup of pasta with some chicken are good examples for post-exercise replenishment.
What foods should be avoided before physical activity?
It is not a good idea to eat protein and fat in the two hours before your physical activity. These foods take longer to digest and can leave you feeling sluggish. Each of your regular meals should contain some protein, fat, and carbohydrate. If you eat a large meal, do not exercise for at least three hours. If you eat a smaller meal, wait 1 1/2 to two hours before exercising.
How often should you eat for optimum energy?
First of all, eat breakfast. When you wake up in the morning, your sugar levels are lower and your body needs food for energy. Skipping breakfast can lead to mid-morning fatigue and lack of energy. Are you one of those people who drinks only coffee in the morning? The alert feeling you get from the caffeine is temporary and doesn't last long.
Furthermore, your metabolism will slow down if you do not give your body enough calories. Eating three meals a day is a good idea. A mid-morning snack and mid-afternoon snack can also help you avoid low energy levels. Good snacks are foods such as fruit, raw veggies or a granola bar. Avoid a large evening meal if you are not going to be very active after your supper. North American culture has made supper the "big" meal of the day. Think of all of your daily meals as important and do not eat too much at supper.
Do not hesitate to see your physician or a dietitian if you have any questions about eating and energy levels. How you eat can greatly influence your performance at work and your success in achieving physical activity goals. Most of all, having that extra energy just makes everyday life more enjoyable.
Dr. Maureen Kennedy MD, CCFP, FCFP, Dip. Sport Med., is a sport and exercise medicine physician at the Sport MB-Sport Medicine Centre and the Reh-Fit Centre in Winnipeg.