Sometimes I get in my car and wonder how much longer it will hold out. I’ve had my car awhile and it’s reliable. All it really needs is an oil change, some gas in the tank and a look at the owner’s manual now and then.

Some of us may feel that way about our own bodies. We don’t want to get injured or hurt. You’ve probably heard that strength training increases muscular strength and endurance, bone mass, connective tissue and lean muscle mass, and reduces the risk of osteoporosis. Strength training makes everyday tasks easier. It also develops the quick reactive muscle actions necessary to avoid falls. All ages benefit, even people over 90 years old, and in particular, postmenopausal women who may experience a more rapid loss of bone mineral density. As the new year unfolds, here are some convincing facts about why and how you might want to do some strength training for some of the 430 muscles in your body.

Moderate-intensity strength training has many health and fitness benefits. The term covers a broad range of resistive loads and modalities, from light manual resistance to plyometric jumps, weight machines, barbells, dumbbells, elastic tubing, medicine balls, stability balls and body weight.

In each example, the exercise causes the muscle to work against a resistance that will lead to muscular adaptations and strength gains. Both men and women respond very similarly to weight training. Women shouldn’t worry about getting “big.” Men have 10 to 30 times more testosterone than females, which causes muscle build-up. In fact, you just may become leaner. Typical increases in lean muscle mass in up to six months of training range from 1 to 4 pounds. However, muscle is more metabolically active than fat, and we lose muscle as we age—two important facts.

The American College of Sports Medicine recommends a minimum of eight to 10 exercises that train the major muscles of the lower body, upper body, abdomen and back, on two to three non-consecutive days per week. The range of movement should be comfortable throughout the full, pain-free range of motion. If it hurts or feels wrong, the exercise needs to be modified to suit your particular muscular or skeletal bio-mechanics.

Beginners will experience adaptations with just one set of exercises, mostly attributable to neurological adaptations than to bigger muscles, but as experience progresses, the sets and repetitions vary. Generally eight to 12 repetitions of an exercise are recommended, but you can vary the reps within the week also.

For example, on Monday try 12 to 15 reps, on Wednesday eight to 10 reps and on Friday three to five reps. That type of undulating system builds in a recovery that allows for better muscle tissue adaptation. Recent studies have shown that women predisposed to osteopenia or osteoporosis build bone better by lower repetitions (six to eight) and heavier weights for site-specific bone improvement, as in a single-arm shoulder raise, or weighted step-ups. Everyone should make sure to warm up for five to 10 minutes beforehand to increase muscle temperature and blood flow. Remember to breathe normally in the lifting and lowering phases of all exercises.

Originally published in the Idaho Mountain Express – Friday, January 11, 2008

Connie Aronson, an American College of Sports Medicine Certified, ACE Gold Certified, & an IDEA Elite personal trainer, works at the YMCA and High Altitude Fitness in Ketchum.