One of factors that keep individuals in a sedentary lifestyle is that there are no immediate, noticeable consequences for unhealthy habits in the younger years. For the sedentary it is slow progression of weight gain, muscle mass loss, and aerobic decline that eventually catches up in older ages resulting in poor health that is then very difficult to change. In his book on pages 120 – 124, The 9 Truths About Weight Loss, (Kirschenbaum, 2000) compares the health changes of women that are sedentary or fit from the ages of 20 thru 70 (reprinted from an article in Self magazine titled “Only the Fit Stay Young”, by Curless, 9/1992). Rather than quote all the age group changes, I have listed comparisons of those in their 20s, 40s and 70s to hopefully inspire the importance of a lifetime of fitness for women and men.
“Twenties – The fit woman…she retains the strength, stamina, and flexibility of her teen years. Her leanness allows the definition of her muscles to show through. Late in this decade her bone strength may reach its peak. If she continues regular weight-bearing exercises, consumes plenty of calcium-rich food and gets adequate caloric intake, her bones will stay healthy for years to come. … The sedentary women… she may look great but physical changes are already beginning to take place that could have far-reaching effects. Her aerobic capacity begins to decline at the rate of 1 percent per year. After age 25, muscle mass can decrease by an average of 5 percent every decade. Metabolism begins to drop at a rate of 2 percent per year, which will translate into increasingly higher body-fat percentages. Any fat added now will be distributed evenly throughout her body. She will begin to experience tightness in her hips.”
“Forties – The fit woman…she remains as energetic and flexible as ever, with excellent aerobic stamina. Because of an inevitable decline in metabolism, however, she may have a tendency to put on some fat – particularly in her hips and thighs. But her high ratio of muscle to fat keeps her calorie-burning capacity up, and this, along with continued aerobic exercise, will counteract this tendency, keeping her at about 22 percent body fat. Although she experiences some compression of the vertebrae in her back, strong muscles keep her stomach relatively flat her back supple. The sedentary woman … she is by now 15 percent weaker than she was in her thirties, and the decline will be even more dramatic past age 45. Her shoulders appear narrower as muscle mass decreases in her upper back. The disks between her vertebrae begin to compress, so that with time she will be 1 to 1 1/2 inches shorter, and her stomach will distend as the distance between her ribs and pelvis decreases. She has lost about 40 percent of the range of motion in her hips and may develop varicose veins.”
“Seventies…The fit woman…she can work and play almost as hard as she did 30 years ago. Only a slight increase in body fat-amplified by the earth’s pull – reveals her age, along with deeper creases in her skin and a drier look to her skin due to decline in oil production that occurs after menopause. The sedentary woman…she is in failing health as high blood pressure, brittle bones and unhealthy blood cholesterol levels leave her vulnerable to a host of serious diseases. Her flexibility, strength and stamina are about nil, and she may have developed the classic ‘dowager’s hump’. She has wrinkles in her cheeks and her mouth turns down, so she appears as unhappy as she probably feels.”