Another good one from Yahoo!:

Give me Strength!
by Susan Moores

For good health, we'd like to see you pick up a few pounds.

Yes, you read that right - but we're not talking about your waist or hips. We mean it literally; lifting weights to build muscle helps keep you lean and fit.

Researchers are learning that a moderate strength-training (weight-lifting) program can do wonders for our bodies. After we turn 30, we lose about 10 percent of our muscle per decade, or a half-pound of muscle every year. That may not sound like much - but by age 70 it means we've been sapped of at least 40 percent of our strength. Lugging a 20-pound bag of groceries at age 30 may be a chore; by age 70 it could be a pipe dream unless we do something to maintain muscle.

Whether you are 20 or 90, strength training stops muscle loss and builds new muscle tissue. That muscle will burn calories, give your body shape, influence your flexibility and sense of balance, and protect you against several diseases.

To a certain extent, strength training even reverses some of the changes normally associated with old age, such as decreased stamina, energy and balance.

The Perks of Pumping Iron

Muscle Out Body Fat. Muscle is greedy for attention - you either use it or lose it, and when it's gone, body fat takes its place. The more body fat you have, the greater your risk of heart disease, adult-onset diabetes and certain cancers. By doing strength training, you keep building muscle, which burns more calories and crowds out body fat. Strength training also helps lower blood pressure and cholesterol levels; heightens your insulin sensitivity, which keeps blood sugar levels normal; and improves blood flow.

Strengthen Bones. Strength training preserves bone. After age 35, women lose approximately half a percent of their bone mass each year. That rate doubles, and may even quadruple, after menopause. Bone loss at this rate can lead to osteoporosis - in fact, one of every two women over age 50 will suffer a bone fracture as a result of osteoporosis. But a study at Tufts University's Center on Aging found that women who participated in strength training not only stopped losing bone density, but actually gained bone mass over a year's time. Those who skipped strength training lost about 2% of their bone density during the same period. More than two dozen other studies support these results.

Improve Reflexes, Balance and Flexibility. Strength training perks up your nerves. Left unchallenged, muscles grow less responsive to messages from the central nervous system. Strength training gives nerves a charge, improving response time to messages sent by your brain. Muscle weakness is also partially to blame for the loss of balance and flexibility that can cause older adults to fall; about 30 percent of people over age 65 take at least one spill a year. Strength training fortifies muscles and strengthens connective tissue, giving joints stability and flexibility.

Boost Recovery from Illness. Strength training significantly reduces incidence of depression and fatigue after an illness, and accelerates a patient's ability to regain the strength and endurance needed for independent living. Studies have shown that strength training can effectively prevent and treat the disabilities that often follow a heart attack. Studies have shown that a strength-training regimen improves quality of life for cardiac-rehab patients.

Maintain a Good Attitude. Strength training can lift your mood and reduce anxiety, tension and stress. Several studies have shown that it reduces symptoms of depression while boosting self-confidence and self-esteem.

As little as two to three 20-minute sessions a week is all it takes to enjoy benefits of strength training. Positive results may become apparent in as little as two months, but there is one requirement: You must stick with a program. Once you stop, the perks go away, too.