If you watched the 1988 Summer Olympics on TV, you'll remember the heroics of a 17-year-old distance swimmer named Janet Evans, whose lack of stature -- five feet four inches and 99 pounds -- and unorthodox (though surprisingly efficient) windmill stroke made her look like an unlikely champion.

But those seeming flaws were outweighed by seemingly inexhaustible endurance and an intense will to win, and the diminutive Southern Californian with the gigantic smile came home from Seoul with three gold medals. Evans went back to the Olympics in 1992 and won another gold, and then competed again in 1996, when she was honored by being chosen to hand the Olympic torch to Muhammad Ali. It was the pinnacle of an athletic career in which she set three world and six American records and earned a spot in the International Swimming Hall of Fame. After swimming, she went on to success as an author, corporate motivational speaker and reality TV show participant.

Fueled by watching TV shows such as The Biggest Loser, a lot of us are obsessed with what we weigh. (Of course, I should talk, since I've got one of those fancy digital scales from Sports Authority that also measures body-fat percentage.) But while poundage is one indicator of health and fitness, it's a sketchy one at best, because it doesn't take into account bone structure and proportion of lean-muscle mass. And the scale can't tell you what's going on inside your arteries after age 40, or what sort of things you're able to do with your body.

While you don't want to throw out your scale or forget about your body mass index, the comparison of weight to height, here are five other numbers that are just as important to watch.

1. Waist Size.

When I checked in this week with North Carolina-based fitness trainer Bobby Morrow, whom I profiled a while back, he wasn't able to talk with me until 10:30 p.m. That's an indication of how many of forty- and fifty-somethings -- the middle-aged exercisers that Morrow specializes in coaching -- are crowding into health clubs, embarking on our perennial New Year's resolution to get in shape. "It's always crazy this time of year," he says, a bit breathlessly.

That we find ourselves making the same fitness resolution year after year, though, should be a hint that there's often something remiss in our approach. Indeed, Morrow says studies have shown that only about 8 percent of the newly resolute who are hoisting dumbbells or trying to figure out how to program the elliptical trainer this week will still be exercising regularly a few months down the road. It could be that their expectations are unduly influenced by TV infomercials, which show preternaturally buff models and promise you can get a six-pack in the time it takes to make three monthly credit card payments.

This week's World AIDS Day ceremony in Washington featured President Obama and Bono, and the theme was "The beginning of the end of AIDS."

The event highlighted the remarkable progress in fighting the HIV epidemic -- the rate of new infections worldwide has declined by 20 percent since 1997, and more people are living longer with HIV than ever before. It's likely that by 2017 -- and perhaps as soon as 2015 -- more than half of all Americans living with HIV will be 50 or older, Daniel Tietz, executive director of the AIDS Community Research Initiative of America, writes at the Huffington Post.

A few years ago, for martial arts instructor Harry Grimm's 50th birthday, his wife treated him to a trip to Bimini. On a snorkeling cruise, the captain of the boat noticed that Grimm was wearing a T-shirt from a seminar by motivational speaker Tony Robbins (who also, it should be mentioned, is a black belt in the Korean martial art of Taekwondo). As it turned out, the captain had once worked for Robbins as a researcher, and he shared with Grimm an interesting bit of research. When Robbins' organization surveyed middle-aged people about what they most wanted to do before they die, "the number one thing was swimming with dolphins," Grimm says. "The number two thing was getting a black belt."

That insight stayed on Grimm's mind when he went back home to Massachusetts, where he ran a successful Kenpo karate school. It made sense to him. Today, on any suburban strip, you're almost as likely to find a Taekwondo studio as a Starbucks, and Ultimate Fighting Championship competitions are becoming a bigger draw on pay-per-view cable than boxing.

Baby boomers are concerned about many potential health woes associated with aging, but next to cancer, the worry that bedevils them the most is memory loss, a recent Associated Press-LifeGoesStrong.com poll (pdf) shows. More than half of boomers surveyed told pollsters they regularly do mental exercises such as crossword puzzles in an effort to stay sharp.

But experts say that you should take a more multifaceted approach to taking care of your gray matter. Here are a few tools and tips to try.

1. Put on your sneakers.

This summer, 55-year-old Craig Szachta joined more than 10,000 runners to compete in the Warrior Dash in Mt. Morris, Mich. The 5K race included some unusual obstacles: a line of old cars, a pond filled with logs, a cargo net, a rock wall, a tunnel of flames and a sinking mud pit.

"It wasn't like running the Boston Marathon," says Szachta, a plant manager at a pipe fabrication company in Clinton Township, Mich. "But it was very challenging.

The Obama administration is abandoning the long-term care insurance that was included in the health-care reform package passed by Congress in 2010 after concluding that the program was financially unworkable.

In a letter to Congress, Secretary of Health and Human Services Kathleen Sebelius announced cancellation of the Community Living Assistance Services and Supports (CLASS) program. The program would have enabled working adults to purchase government-administered insurance to cover their nonmedical costs if they became disabled and needed help with daily living activities such as bathing, dressing and housework. The insurance also could have been used to cover the cost of special technology and transportation for the disabled. (Here's a SecondAct column by Mark Miller on the program.)

There are 44 million men in the U.S. who are 50 and older, and 33 million of them already have had a Prostate-Specific Antigen test, or PSA test, which long has been touted as an important tool for early detection of prostate cancer. That's why it came as such a shock this week when news broke that a key government panel will recommend that men no longer routinely take the PSA test because, from a statistical standpoint, its use actually may do more harm than good.

The U.S. Preventive Services Task Force has issued a draft report concluding that, based on five major clinical trials, the PSA test does not significantly reduce the mortality rate from prostate cancer, which kills nearly 34,000 men annually. Moreover, the panel found that the PSA test's routine use actually leads in many cases to tests and treatments that needlessly subject men to side effects such as impotence and incontinence.

Martina Navratilova played tennis so long -- until she was 49 -- that by the end of her pro career, she says she was older than almost everyone on the circuit, including players, trainers, and even players' mothers.

After Navratilova turned 50, she became a nutrition and fitness ambassador for AARP, the advocacy group for people 50 and older. Just like that, she went from being the oldest in the group to the youngest. And that's what surprised her most about life after 50. "I'm young again," she says.