When his close friend Jack Kelly, a former Olympic rower, collapsed and died of heart failure immediately after a regular workout (a couple hours of rowing followed by a five-mile run), a distraught Irving Dardik needed to know why. Kelly was a world-class athlete in prime physical condition, after all. That his most sharply defined muscle would give out during the prime of his life defied reason.
When Dardik, a physician, went looking for answers, he found that his friend was not alone. What's more, when he started looking at cases in which well-trained athletes died of heart failure associated with exercise, he found that more often than not the collapse came after, not during, an activity. 'I began to think that it must be something in the way people exercise that causes heart failure,' he says in Roger Lewin's book Making Waves: Irving Dardik and His Superwave Theory (Rodale, 2005).
Most people who exercise, including top-notch athletes, do so at a constant heart-pounding level for long stretches of time. In part this is because trainers and other sports professionals have long been vested in this approach. In part it's because the media continue to condition folks to believe that without pain (or at least a little discomfort) there can be no gain. According to Dardik, though, it's not only unnatural to endure extreme tension for lengthy periods -- it's unhealthy.
Everything in nature, he says, moves in continuous wavelike cycles -- from the rhythms of sunrise and sunset to our daily fluctuations in temperature and blood pressure to the way animals move in short bursts of activity then stop to rest. Dardik believes we should exercise with those same life cycles -- that same ebb and flow -- in mind. (His decades-long research revealed that Olympic sprinters tend to be healthier than marathon runners.)
Each aerobic workout should include cycles of exertion and rest. Exercise for a while, then stop and rest. Exercise for a while, then stop and rest again. And again. Not only will this method prove to be a bit easier than literally running yourself ragged, it might just save your life.