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Consumer information

How to help clients select and monitor effort level

by Reed Humphrey, Ph.D., P.T.

In a perfect world, everyone would visit a healthcare provider for a graded exercise stress test before starting an exercise program, from which specific exercise targets could be derived, i.e. appropriate exercise heart rate or workload. In reality, a stress test is a wise investment for those who are inactive, have a history of heart or circulatory problems, and/or have the accepted risk factors for heart or circulatory problems (i.e. smoking, high blood pressure, high cholesterol or diabetes or a family history of these problems) as the test screens for exercise safety.

When an individual is thought to be healthy and already active—the assumption when a healthcare provider decides against a stress test— health and wellness professionals can suggest a submaximal fitness test, in which the client's heart rate and perceived exertion information is collected while he/she exercises on a treadmill or cycle ergometer. (Again, it's assumed the client is healthy and that a medically unsupervised test is safe for him/her.) Following the test, the health or wellness professional can provide this individual with specific parameters for exercise effort based on this evaluation.

If the submaximal test is not available, health and wellness professionals can suggest that clients measure their exercise heart rate using common formulas, such as subtracting their age from 220 to predict maximum heart rate, or that they subjectively assess their effort through breathing or "conversational limit" effort.

Legitimate concerns have been raised about the 220-minus-age formula. These concerns include the scientific knowledge that people's ability to predict their maximum heart rate varies substantially at any given age. Commonly, people will err by 10 beats in either direction, or even twice that magnitude. A newer formula was recently introduced that reduces the prediction error, but only slightly, and this error is known to increase even more so in older adults. In addition, a variety of medications, such as beta-blockers, influence the heart rate response, so the risk of using a prediction equation to estimate exercise intensity probably exceeds the benefit and is not recommended, particularly for older adults.

No matter the intensity level at which older clients exercise, they should consult their healthcare provider before continuing an exercise program if they have any unusual discomfort, dizziness or lightheadedness during exercise, or if they feel excessively fatigued or "just don't feel right."

Reed Humphrey, Ph.D., P.T., is an associate professor in the Department of Physical & Occupational Therapy at Idaho State University. He is currently U.S. Delegate and Secretary-General, World Council for Cardiovascular and Pulmonary Rehabilitation, plus a fellow and past president (1995-96) of the American Association of Cardiovascular and Pulmonary Rehabilitation. Humphrey is also a fellow of the American College of Sports Medicine, and served as associate editor of ACSM's Guidelines for Graded Exercise Testing and Prescription, fifth edition, and the recently published ACSM's Resources for Clinical Exercise Physiology.

Disclaimer: This information is not intended to replace a one-on-one relationship with a qualified healthcare professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from research. The ICAA encourages you to make your own health and business decisions based upon your research and in partnership with a qualified professional qualified professional.

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