The Relationship Between Physical Activity and Exercise

To prevent heart disease and other illnesses and to improve general health it is important to make regular exercise a part of your life. However, what happens very often is that the person starts exercising for one hour a day but spends the remaining 23 hours being as sedentary as possible. It is quite a common sight to see people taking a lift to go to their gym, even though it may be on the first floor! While it is important to ‘exercise’ on a regular basis it is equally important to add physical activity to your lifestyle.

The terms physical activity and exercise may seem synonymous, but there are critical differences between the two.

• Physical activity encompasses any movement of the body produced by the skeletal muscles that requires energy expenditure. Everything from washing dishes to walking up the steps falls under this umbrella.

• Exercise is a subcategory of physical activity. It refers specifically to planned, structured and repetitive physical activity geared toward achieving or maintaining physical fitness.

Levels of physical activity can be viewed on a continuous scale. At one end of the spectrum is a sedentary lifestyle, characterized by prolonged periods of sitting, reclining or lying while awake and using very little energy. At the other end are high levels of exercise training, such as those exhibited by well-conditioned athletes.

How you move along this continuum depends on both your starting point and your exercise goals. If you are currently sedentary, simply increasing the amount of physical activity in your daily life is an important push forward.

At a certain point, however, you may need to establish an exercise program to continue making strides. And once you have a program in place, you should periodically review your fitness level and reexamine your personal goals to determine how you can continue to make progress.

It is important to remember that some physical activity is better than none. If you are currently inactive, start with small amounts and gradually increase the frequency, intensity and duration of your activity over time.

For most adults, current recommendations are to aim for at least 150–300 minutes of moderate-intensity aerobic physical activity per week, or 75–150 minutes of vigorous-intensity activity, or an equivalent combination of both. Adults should also include muscle-strengthening activities involving the major muscle groups on at least two days a week.

How Your Body Responds to Physical Activity and Exercise

When you call on your body to perform any type of physical work — even something as simple as walking across the room — your cells are called upon to produce and use more energy. What follows is a complicated set of physical processes that supply the cells with the extra energy they need.

As the demand for energy increases, the respiratory and circulatory systems respond by increasing the delivery of oxygen and nutrients to the working muscles. At the same time, the muscles increase their use of stored fuels and nutrients to produce the energy required for movement.

This increased metabolic activity also results in the production of carbon dioxide, heat and other metabolic by-products. It is because of these processes that you breathe more rapidly and your heart pumps more vigorously when you exert yourself.

Another byproduct of increased energy production is heat. Sweating is one of the body's important mechanisms for regulating body temperature by helping the body lose heat, particularly during more prolonged or strenuous activity and in warm or humid conditions.

The Benefits of Physical Activity and Exercise

Physical activity (and exercise) is a cornerstone of a healthy lifestyle. Not only does physical activity make you look and feel better, but it is also important for improving your health and reducing the risk of many chronic diseases.

Regular physical activity is associated with a lower risk of premature death, heart disease, high blood pressure, type 2 diabetes and several types of cancer. In addition, remaining active throughout your life can help you maintain physical function, independence and quality of life as you age.

Here's a list of the benefits you can expect from regular activity:

• Lower risk of premature death

• Lower risk of heart disease and stroke

• Lower risk of high blood pressure (If your blood pressure is already elevated, regular physical activity can help lower it.)

• Better weight control

• Lower risk of type 2 diabetes

• Lower risk of certain cancers, including colon and breast cancer

• Increased bone strength

• Improved balance and physical function

• Lower risk of depression and anxiety

• Improved sleep

• Increased energy level

• Overall sense of well-being

Simple ways to be more physically active:

• Take the stairs instead of the elevator

• Park the car a little further away from your destination

• Walk to the grocery store, instead of taking the car

• Do more house-work

• Take short movement breaks if you have been sitting for a prolonged period

• Walk whenever possible instead of using a vehicle for short distances

Remember: Move more, sit less. Physical activity does not have to happen only in a gym or as part of a formal exercise program. Movement accumulated throughout the day also counts.

Author: Dr. Aashish Contractor is India's pioneer in cardiac rehabilitation and the Founding Medical Director of the Mumbai Marathon. With over 25 years of experience, he has guided hundreds of heart patients to run safely.