Several reports have been published on the importance of physical activity to improve the overall health of Americans. The American Heart Association, American College of Sports Medicine, National Institutes of Health, and the U.S. Surgeon General agree that adults should partake in at least 30 minutes of moderate intensity physical activity each day to achieve the beneficial effects. These reports are based on studies that looked at the relationship between physical activity and cardiovascular disease. However, those studies looked at exercise in two distinct ways, physical activity and cardiovascular fitness.
- Physical activity can be measured as self-reported activity (leisure-time or total activity) during a certain period of time (2 weeks to 12 months).
- Energy Expenditure can be determined by analyzing how vigorous and for how long each activity type was engaged in.
- Cardiovascular fitness can be determined from performance on cycle or treadmill tests.
The levels of physical activity and fitness have been compared to cardiovascular disease events to determine the role each plays in delaying or preventing heart disease.
Recently, in a paper published in Medicine & Science in Sports & Exercise, the author, Paul Williams, asked the question, should lack of physical activity and cardiovascular fitness both be considered separate risk factors for heart disease? 1
The author looked at 23 studies of physical activity or fitness and analyzed the results. He concluded that both those who are physically fit and those who are physically active have less risk for cardiovascular events. However, higher fitness levels impart greater risk reduction than just increased activity levels alone. This suggests that activities that do not lead to an improvement in physical fitness provide less benefit than activities that improve fitness levels. While participation in regular activity programs is beneficial, significantly more benefit can be gained if the activity is of appropriate intensity and duration to improve fitness levels too.
The bottom line – both physical activity and fitness should be considered when determining cardiovascular risk. It is important to not only participate in regular physical activity but the activity should be tailored to the individual’s current fitness level to optimize improvements in fitness level.
Because low fitness levels carry increased risk for cardiovascular events, exercise testing as part of a regular physical exam, should be considered for men over 40 years of age and women over 50 years of age, especially for those with more than two other traditional risk factors for development of coronary artery disease.
To make an appointment with an exercise specialist or to join a cardiac rehabilitation program, contact the Cleveland Clinic Preventive Cardiology - 216.444.9353 or 800.223.2273 ext. 9353.
- Williams PT. Physical fitness and activity as separate heart disease risk factors: a meta-analysis. Medicine and Science in Sports and Exercise 2001; 33:754-761.
- Blair SN and Jackson AS. Editorial to accompany: Physical fitness and activity as separate heart disease risk factors: a meta-analysis. Medicine and Science in Sports and Exercise 2001;33:762-764