Diet and exercise are two lifestyle factors that play important roles in reducing the risk of many chronic diseases. For many of these chronic diseases, diet and exercise are each listed as modifiable independent risk factors. What this means is that both diet and exercise are required elements of a healthful lifestyle. Developing a healthful eating plan without considering your activity level or initiating an exercise program without taking your diet into consideration isn’t as preventative as including both as part of your healthful lifestyle plan.
Diet and exercise have been shown to reduce the risk of heart disease, diabetes, obesity, osteoporosis, and cancer. Specifically, exercise has been shown to help control blood cholesterol levels, prevent and control type II diabetes and obesity, lower blood pressure in hypertensive individuals, decrease cardiovascular disease mortality, strengthen bones, and reduce stress and the symptoms associated with anxiety and depression.
In addition to lowering the risk of chronic disease, aerobic exercise has also been shown to have positive psychological effects. Active individuals, as compared to sedentary individuals, are more likely to be better adjusted, have improved cognitive function, lower cardiovascular responses to stress (i.e. blood pressure elevation), and experience fewer symptoms of anxiety and depression. Exercise also improves one’s self-confidence and self-esteem.
The primary principle for reaching and maintaining a healthy weight is regulated by energy intake and output. In other words, in order to maintain your weight, the energy your body derives from what you eat (calories) has to equal the amount of energy your body uses each day to perform its different functions. Energy is needed for three major functions: maintenance of basic body functions, metabolizing the nutrients in food, and fueling physical activity.
Physical activity accounts for 15 to 30% of the body’s energy expenditure. This value varies from individual to individual. For example, a person who goes for a moderate 30-minute walk each day will require an extra 200 calories whereas a marathon runner may expend an extra 2,000 calories per day while training.
The energy required by an activity depends on the type and duration of the activity. A woman weighing 140 pounds will require approximately 2-1/2 times more energy to run a 9-minute mile versus walking the mile at a moderate pace. Also bicycling requires less work than running the same distance. The amount of energy expended also depends on the duration of the exercise. Walking at a consistent pace for 60 minutes will require 6 times more energy than walking for 10 minutes.
The size of the individual also affects the amount of energy required for an activity. A heavier individual will burn more calories doing the same activity as a lighter individual. For example, an overweight person will expend more calories walking a mile than their normal-weight counterpart. One exercise where this principle does not apply is swimming. The buoyancy of body fat will actually decrease the energy expenditure for an overweight individual.
The composition of your diet should not change if you are considering incorporating exercise into your daily routine. The components of a healthful eating plan discussed in part two of this series, “Adopting a Balanced Eating Plan” pertain to both the hard-core athlete and the individual walking 30-minutes each day.
Carbohydrates are the main source of energy for your muscles and brain to function properly. Carbohydrates should make up at least 60% of your diet. Focus on complex carbohydrates such as whole-grain cereals, breads and pastas, fruits, and vegetables. A balanced diet should derive approximately 10% of its calories from protein. Remember, 1 gram protein = 4 calories, therefore a person eating an 1,800 calorie diet would need approximately 45-50 grams of protein.
Don’t forget to drink plenty of fluids. Proper hydration is essential before, during, and after exercising. Drink 2 cups of liquids 2 hours before working out, 1/2 cup ten minutes before, and 1/2 cup every 10 minutes during your workout. After training, drink 2 cups for every pound of fluids lost.
As with making positive changes in the diet, increasing your physical activity level has many far-reaching health advantages. Exercise not only helps you reach and maintain your desired body weight, but will also reduce the risk for many of the chronic diseases and enhance your psychological, cognitive, and emotional well-being. Remember for reaching and maintaining maximum health; incorporate both diet and exercise into your daily lifestyle plan!
If you haven’t already, start some type of physical activity today. Walking is a great place to start. A brisk walk, 30-45 minutes a day will help you to lose the weight and keep it off. If you’ve been fairly inactive and want to start exercising, start slowly by adding a few minutes of activity each day – don’t try running a marathon your first day out! If you try too much all at once, you’ll get frustrated and lose your motivation. Another suggestion is to find one or two exercise partners. Sharing an activity is not only fun, but can also get you out there on those days when you are making excuses not to exercise.
Remember, developing a new eating and exercise plan should be fun – not a chore! If you find you don’t like a particular exercise, try a different activity. Write down activities you enjoy and make a reasonable plan to include one or two of these activities into your daily routine.