It has been said that the Baby Boom generation is redefining middle age. Activities once the domain of "youngsters" in their 30s and 40s are now being avidly pursued by boomers in their 50s and 60s.

Regional news coverage of the 2005 Summer National Senior Games, better known as the Senior Olympics, being held in Pittsburgh this week has focused attention on the athletic capabilities and accomplishments of older Americans. There have been stories in the Butler Eagle and other media about: a 63-year-old triathelete, a 69-year-old swimmer, an 85-year-old track and field competitor, a 70-year-old basketball player, 66-year-old badminton player, and even a 103-year-old bowler.

As remarkable as the accomplishments of some of these older athletes are, the broader and more important message from the Senior Olympics is that being physically active in the second half of life is not only possible, but medically advisable.

Eligibility for the Senior Olympics begins at age 50, a mid-life marker once viewed as the beginning of a gradual and inevitable decline in physical activity. The 10,000-plus athletes competing in Pittsburgh have demonstrated that 50, or even 60 or 70, can be more of a beginning than an end in terms of participation in sports.

Researchers from the University of Pittsburgh Medical Center (UPMC) have been gathering information from the athletes competing in Pittsburgh. The UMPC researchers began studying older athletes at the 2001 summer games in Baton Rouge, La., and are looking at the lives of these older people with active and healthy lifestyles and comparing them with the lives of their more sedentary cohorts.

The researchers' findings will be added to the already substantial evidence that shows that there are many physical and mental benefits to a regiment of regular physical exercise.

Though it defies conventional thinking about aging, many of today's senior athletes have found that they are now in better shape than when they were 10 or even 20 years younger. Freddie Fu, the nationally-known orthopedic surgeon and sports-medicine specialist at the University of Pittsburgh, added support to that message when he said recently, "It's not uncommon for Senior Olympics athletes to run, swim or throw faster than sedentary people 20 to 30 years their junior."

For female competitors, the effect of increased physical activity has been shown to produce a dramatic improvement in bone density. Fu noted that more than 50 percent of female competitors at the Senior Olympics, including some approaching age 80, had normal bone density, compared to the much lower bone density levels generally found in older women.

Aging is a fact of life and no amount of exercise will stave off some inevitable decline, which researchers say typically begins around age 75. But, today's seniors and many of the 75 million baby boomers rapidly approaching senior citizen status will no doubt test the limits of what it means to be 70 or 75 yeas old in terms of remaining physically active and maintaining a high quality of life.

The athletes competing in the Senior Olympics should provide inspiration and motivation for others, who have seen their 50th, 60th or even 70th birthday come and go, to get off the couch and commit to some form of regular exercise.

Those who resist the sedentary lifestyle formerly associated with retirement and the senior-citizen years, will probably find they have plenty of company and they are also building a foundation for a healthier and happier life.