To wit, new buzz around the 6 minute workout is with us again. Last month, The New York Times Health section published an article on getting fit with only a few, short, but very high intensity workouts per week. Studies in Japan on rats, and in Canada on humans have found that short, intense bouts of exercise not only achieved comparable fitness levels to subjects who completed much longer, but much less intense exercise. Also ... and here's the kicker ... they also achieved the same endurance benefits!
While encouraging indeed, as the old adage goes, if it sounds to good to be true, it probably is.
For starters, the short duration, extremely intensity workout regimen isn't entirely new. Check out Crossfit.com for a peek at some of the zaniest things I've ever seen to create additional physical stress on the body. The principles applied are simple enough: shock and overload the body so that it must adapt. Trainers all over the country do the same thing with their clients, but they do so in a more controlled, safe and moderate way.
Perhaps a military, 20 something body can tolerate, even thrive, on short bouts of extreme overload and shock. However, people new to exercise, and those in their middle or golden years will simply break eventually with that kind of approach!
Don't get me wrong, intense exercise has it's time and place in an overall exercise program, but to use ONLY extremely intense exercise is complete nonsense!
Yes, it's true that when you exercise at extremely intense levels your calorie demands could be as much as 10 times that at a moderate level. And it's also true that that kind of exercise promotes fitness adaption that can only be achieved with those kinds of intensity levels.
But it fails to do many favors for your tendons, joints, and ligaments. Or your skeletal alignment. Tweek your back a bit sprinting up a hill with a 50 pound pack (crossfit.com) ,and you'll develop headaches, sleep poorly, and develop other aches and pains.
Lower intensity exercise has been proven to help boost the immune system and fight off infection. If you exercise intensely with a viral infection, you'll only prolong the infection, whereas moderate or low intensity exercise can actually help you fight off the bugs.
Additionally, regular, moderate intensity exercise has been shown to help prevent osteoporosis.
Not to mention that high intensity cardiovascular exercise does little to help develop joint strength and stability that can be only developed with sufficient and proper resistance work.
And if that's not enough, you'd also be missing out on the many and varied benefits of 'regular' exercise: Increased Energy Levels; Reduced Stress; Sleeping Better; Better Sex; Eating Healthy, Avoidance of Depression; Reduction in the Risk of Developing Heart Disease and many Cancers; and on and on and on.
Again, it belongs in an overall fitness program, but simply can't stand alone.