Exercise, Fitness

January 23, 2009

A Few More Fitness Myths…

Given the overwhelmingly positive feedback on my previous posts debunking common exercise myths, here are my insights on a few more myths that continue to pervade the industry.

Hopefully by setting the record straight, we can put these misperceptions to rest once and for all and, in the process, improve your toning and weight losss results!

MYTH: Using the Stairmaster will give you a big butt.

TRUTH: This myth might be humorous if so many women didn’t accept it as fact. It came about after a popular magazine quoted a so-called fitness expert who cautioned that stair climbing was a one-way ticket to a movie screen-sized derriere. The “expert” apparently had never studied exercise physiology.

Truth is it’s virtually impossible to substantially increase muscle mass from stair climbing… or any other aerobic activity for that matter. Understand that during cardiovascular exercise the primary type of muscle fibers utilized are the endurance-related slow-twitch fibers. These fibers get much of their energy by burning fat for fuel, contracting very slowly but having the ability to endure extended periods of activity.

The kicker: Slow twitch fibers have only a limited ability to increase in size. It’s the strength-related fast-twitch fibers that have the capacity to grow sufficiently large. And since fast twitch fibers aren’t recruited to any great extent, the chances of your butt beefing up are just about nil.

Bottom Line: If you enjoy using the Stairmaster, go ahead and climb away without worrying that your booty will expand to the size of a city bus. If anything, you’ll ultimately reduce the size of your butt due to its fat-burning effects.

MYTH: Women should train with very light weights so they won’t bulk up.

TRUTH: Go into any gym and you’ll invariably notice women lifting weights that are far too light for their abilities. I’ve actually seen women talking on their cell phones while doing a set of curls or reading magazines while doing leg presses. In most cases, this is a conscious decision due to an inherent fear of looking like a she-man.

The fear, however, is completely unfounded.

Women have very low levels of testosterone — the body’s primary muscle-building hormone. On average, women produce only about 1/20th the amount of testosterone as their male counterparts. This is nature’s way of preserving “femininity.” As a result, it’s difficult for women to add a significant amount of muscular bulk to their frame.

Without an anabolic stimulus, muscle tissue simply has no impetus to grow larger (hypertrophy) and muscular growth remains modest, even at advanced levels of training.

Bottom Line: If your goal is to tone up, then you need to lift weights that sufficiently tax your body. If you don’t challenge your body beyond its present capacity, you simply won’t provide a stimulus for improving body composition. Your goal should be to choose a weight that causes you to struggle on the last few reps. If you’re not struggling, the weight is too light!

MYTH: Lactic acid causes muscle soreness.

TRUTH: Contrary to popular belief, lactic acid is not the bad boy of exercise that some make it out to be. It certainly is not involved in making you sore after a workout.

Truth is any lactic acid that accumulates in muscle is rapidly cleared within an hour or two after exercise. Since delayed onset muscle soreness (DOMS) doesn’t manifest until about 24 hours after a training session, it therefore follows that lactic acid cannot play a role in its origin.

So what causes DOMS? It’s actually a product of damage to muscle tissue. Intense exercise produces small microtears in the working muscle fibers, primarily as a result of eccentric activity (i.e. lengthening a muscle against tension). These microtears allow calcium to escape from the muscles, disrupting their intracellular balance. Metabolic waste is produced and that interacts with the free nerve endings surrounding the damaged fibers, resulting in localized pain and stiffness.

In response, white blood cells migrate to the site of injury, generating free radicals that further exacerbate the sensation of pain. The discomfort can last for several days or even up to a week, depending on the extent of muscle damage.

Bottom Line: Don’t blame lactic acid buildup for making you sore after a workout. It’s merely a sign that you’ve trained hard. If you experience DOMS, the best thing you can do is to stay active, enhancing blood flow to the affected area. This will expedite nutrients to the muscles, accelerating the rate of their repair and consequently reducing associated discomfort.

Until next time, stay fit!

Brad