1. Archive

An enlarged "athletic heart' can be a good or bad thing

Question: My husband is a runner, and our doctor says he has an "athletic heart." My father, who has avoided exercise all his life, has high blood pressure, and his doctor says he has an "athletic heart." Is there a difference between the two? If so, what is it? Answer: An "athletic heart" is an enlarged heart. Both exercise and disease can cause it. It results from continually stressing the heart muscle. But there are major differences between an athletic heart caused by exercise and one caused by disease.

Your husband's athletic heart is very likely a normal adaptation that is seen in almost everyone who exercises regularly _ including children and older people. In runners, and other endurance athletes, the enlargement is primarily due to an increase in the size of the heart's left ventricle cavity and the thickening of its walls. (The left ventricle pushes blood out to the tissues.) These changes strengthen the heart and allow it to pump more blood. As a result, more oxygen and nutrients get to working muscles, and endurance is improved.

Your father's athletic heart may be caused by his high blood pressure. The hearts of people with high blood pressure must work harder to overcome the resistance resulting from the narrowing of the blood vessels. In an attempt to meet this demand, the heart's left ventricle wall also thickens, but the cavity does not increase in size. In addition, the thickening of the wall is usually accompanied by the formation of fibrous tissue, or gristle, in the heart muscle. Consequently, the muscle stiffens and becomes weaker and less efficient.

Cross training evens

fitness capabilities

Question: Can you tell me a little about cross-training? This seems to be the newest fitness craze.

Answer: Cross-training is not new. It's just that over the last decade the mushrooming interest in the triathalon (running, swimming and cycling) has popularized this concept. Cross-training simply refers to regular participation in two or more somewhat dissimilar activities or using a secondary activity (very often, weight training) to help prepare for a primary activity (say, football).

This type of training has a number of advantages, and it is highly recommended as a way to keep fit or to train for competition. Cross-training can lead to better all-around conditioning, for example, by combining an upper body activity (swimming) with a lower body one (walking). And alternating between different activities decreases the potential for over-use injuries. Cross-training can help ward off boredom and staleness and may add convenience to your exercise schedule (if the pool is closed, you can always run, or perhaps lift weights). In addition, this type of training is very useful for rehabilitation purposes and to strengthen specific athletic weaknesses.

The main disadvantage to cross-training is that some people go too far with the idea. They overexercise which, of course, defeats the purpose. Also, keep in mind that if you are training for competition, the highest state of conditioning in a single activity is achieved by training in that activity. So, if you wanted to be a great cyclist, for instance, the lion's share of your training time should be spent cycling.

Write with questions to Dr. Patrick J. Bird, Dean of the College of Health and Human Performance, University of Florida, Gainesville, Fla. 32611.


The Health & Fitness pages are coordinated by Jim Melvin. Comments may be addressed to: Jim Melvin, St. Petersburg Times, Floridian, P.O. Box 419, St. Petersburg, Fla. 33731-0419.