Strength begins a downward spiral as we age; bone and muscle loss begin a slow descent in the mid 30s. Between the ages of 50 and 70, strength can decrease about 15 percent every decade. If left unattended, strength decreases considerably after age 70, leaving in its wake much weakness and disability. [William Evans] refers to this stage as the Disability Zone.

Stronger muscles also boost metabolism. If you are inactive as you age, the decrease in muscular strength can cause your basal metabolic rate, or BMR, to drop. BMR refers to how many calories you burn at rest to maintain vital bodily functions, such as breathing, heartbeat and brain activity. Your BMR accounts for half or more of your daily caloric expenditure.

The pelvic tilt is an excellent exercise you can do at home for the lower back, abdominals and hamstrings all in one. Lying on your back with bent knees, place feet flat on the floor, about hip-width distance apart. Keeping your head, neck and shoulders relaxed, contract abdominals, which will lower your back to the floor. Keeping your back on the floor, tighten the buttock muscles and lift the tailbone off the floor just a few inches. Hold for a few seconds, then slowly release to the floor without arching your back.