A 3 Part Series: Nothing to Sweat! - Part 2

Component 2: Strength Building Exercise

There’s more to fitness than just a healthy heart, of course. You need some muscle power to go with it, and not just for moving refrigerators or carrying heavy bags of groceries. Muscle is vitally important for weight control, because muscle is the best calorie-burning tissue the body has. It’s more effective than fat even when at rest, and its calorie-burning ability can leap as much as 20-fold when called into action. The more muscle we have, therefore, the better at burning calories we’re going to be — even while just watching the evening news!

This is why people who do only aerobic exercise, which is not effective at building muscle, tend to gain weight so quickly if they stop: With relatively little muscle mass to fall back on, their calorie—burning is dependent almost entirely on what they use up during their aerobic workouts. If they’re suddenly derailed by an injury -— or an exceptionally busy schedule — boom: Calorie-burning stops and fat production begins if appropriate dietary cutbacks are not made.

Maybe crawling inside a muscle to see what it really looks like will help illustrate why this is so.

Muscle tissue is composed of two types of fibers. Within each of the 650 muscles we have, two types of muscle fibers lie side by side: fast-twitch and slow-twitch. When a muscle is exercised aerobically (that is, in the continuous, rhythmic fashion mentioned above), it is primarily the muscle’s slow-twitch fibers that get called into action. These fibers gain in endurance from such activity, but they do not increase in strength or size — thus, the birdlike physiques of most good marathoners. Despite their grueling 100-plus-mile-a-week training regimens, there is no appreciable increase in the muscular bulk of their legs. Their legs often get even thinner, in fact, as unused fast-twitch fibers shrink and in some cases even die,

When a muscle is exercised in a strength-building way, however, fast-twitch fibers get the call, and their response— is to increase in size, This is why the folks in those muscle-building magazines look the way they do.

Their exercise routines focus primarily on the development ol their muscles’ fast-twitch fibers, and yes, some amazing growth can be the result.

But hold the dumbbells — who wants that Amold Schwarzenegger look, especialy if you’re a woman who just wants to be slimmer?

Be careful. Studies show that the losses in muscle mass and strength that we suffer with age are due almost entirely to atrophy of our fast»twitch, not our slow-twitch, fibers. This is because our slow-twitchers get called upon by even the most minimal exertions. Our fast-twitch fibers, by contrast, sit around and do little more than twiddle their thumbs as we age, eventually disappearing entirely if we don’t remind them we know they’re there. This disappearing act can begin in earnest as early as our 30s, and if left unchecked can progress to truly a pathetic degree. Surveys show, for example, that over one»quarter of American men and two-thirds of American women cannot lift more than 10 pounds by the time they reach age 75. Fast-twitch neglect has been targeted as the primary cause.

Some loss of muscle and strength with age is inevitable, don’t get me wrong. But when someone like fitness dynamo jack LaLanne can commemorate his 65th birthday by swimming 1% miles towing 65 rowboats loaded with 65,000 pounds of wood pulp —— while wearing hand-cuffs! — it’s clear that many of us are letting Father Time get away with far more than we have to.

Don’t worry, though. I’m not going to be recommending the daily diet of push»ups that have earned ageless Jack his legendary acclaim. I’ll simply be showing you how to incorporate the recommended 5 to 10 minutes of strength-building activities naturally even advantageously — into your busy life.