It's a hard fact to face, but we're all getting older. And as we age, our bodies change by gaining fat, reducing muscle mass and losing flexibility. Those deepening lines around the eyes don't help either. But just because aging is inevitable doesn't mean that we should immediately kick back and retire to the Barcalounger.

In fact, most of the changes we associate with aging are actually a result of becoming less active. A recent study in the British Journal of Sports Medicine found that by staying aerobically fit, you can delay biological aging by 10 or more years. Other research has shown that exercise increases mood and social interaction, helps prevent, delay or improve diabetes and heart disease, and strengthens muscles and bones.

Experts at Life Fitness, a designer and manufacturer of exercise equipment, recommend a daily dose of activity to battle aging: Even if you've lead a mostly inactive lifestyle or let those free weights collect dust, exercising today can help you have a healthier tomorrow.

Research suggests exercise can improve strength, balance and flexibility at any age. And getting active doesn't mean training for the next marathon. The American College of Sports Medicine recommends 30 minutes of moderately intense aerobic exercise five days a week for good health.

Some tips:

• Focus on mobility and flexibility: While you may love an intense basketball game or ice hockey battle now, odds are those activities won't sound so good at 75. Create variety in your routine with exercises you can enjoy for decades such as walking, biking, swimming or yoga.

• Add weight-bearing exercises: Our muscle fibers shrink in size starting around age 40, which contributes to a decrease in strength, balance and coordination. Fortunately, resistance training can reverse this trend by increasing our muscle fiber size as well as increasing bone mass, which prevents osteoporosis, arthritis and sarcopenia. The American College of Sports Medicine recommends that adults weight train 20 to 30 minutes a couple of times a week.

• Keep skin glowing: Exercise is a proven stress-reliever, which besides sun exposure, is one of the greatest threats to our skin and our psyche. Some blood-pumping activity also brings out that bright, healthy glow at any age.