Not everyone who reads this column is over 50, and only a handful of those go all out when they go out and exercise. Why devote a column then about Joe Friel's endurance sports book, Fast After 50?

Because even though only a few 50-plus readers care about running, cycling, skiing, or swimming as fast as possible, many 30-plus readers care about aging as slowly as possible. While Friel acknowledges that you can never ultimately defeat Father Time, he does explain how you can break even against him - and even sometimes overcome him! - in many early battles.While his advice is geared toward the 50-plus athlete striving for optimal performance, any 30-plus exerciser can apply Friel's anti-aging exercise formula and benefit from it - provided they too believe that much of what is accepted as "normal" aging is really accelerated aging and therefore not really normal at all.Friel did extensive research - 20-plus pages of references prove that! - to help create a list of the normal symptoms of aging: the graying of hair, the loss of skin elasticity, the decrease in sleep quality, the compression of joints, the loss of bone minerals, and the reduction of the metabolic rate. You'll experience these sooner rather than later, he believes, if you've come to see something else as normal: "sit[ting] in front of a TV eating potato chips."But if your view of normal is "to be active, to move vigorously and strenuously," Friel says you can definitely delay the inevitable. He then admits that working out like a madman when you've been on the earth for more than a half century isn't normal either, but that abnormality is good.It lessens the likelihood of you encountering the major after-50 health hurdles: osteoporosis, hypothyroidism, type 2 diabetes, high blood pressure, cancer, coronary heart disease, Alzheimer's disease, Parkinson's disease, and dementia.Any old exercise, though, won't halt the symptoms of aging that lead to a decrease in athletic performance: the loss of aerobic capacity, the reduction of maximal heart rate, the decrease in blood volume overall and per heartbeat, and the loss of muscle mass. Friel does offer a way, however, to slow and sometimes even reverse these symptoms - though it seems counterintuitive to the common man.As most exercisers age, the concession they make is to reduce the intensity of exercise. While some also shorten the length of workouts, many do the opposite: to compensate for the reduction of intensity.In particular, aging bicyclists often make this mistake. They know they're riding slower, so they ride farther and longer.Friel cites a number of studies that show the devoted exercisers who reduce intensity age slower than the sedentary - but faster than those who do their darnedest to equal their earlier levels of intensity.For those of you who just read the last sentence and believe it's impossible for you to duplicate the intensity of the workouts you did 10, five, or even two years ago, don't fret. While your belief could very well be true, Friel believes all you really need to do is give the same effort, not produce the same results.And if a concession needs to be made in order to produce a more intense effort, reduce the amount of time you exercise.In other words, if you can no longer do a four-hour bicycle ride where you pedal at race pace for one hour, ride for three hours, even two and a half - any amount that still allows you to ride one hour at race pace - even if race pace is no longer quite as fast as it once was.The pace doesn't matter as much as the intensity of the effort. That's what Friel has found counteracts the aging that leads to diminished athletic performance.But counteracting aging is not the same as reversing it. Because of that, Friel also preaches that older athletes need increased recovery time, not only to be able to reach a higher level of intensity but also to avoid injury.While Friel provides concrete examples on how implement all of this into a yearlong plan, that's outside the scope of this article. If you're interested in performing a sport at a high level as you age, buy Friel's book. You won't be sorry.For the recreational exerciser who wants to delay the aging process for as long as possible without reading a book geared toward competition, simply keep Friel's formula in mind when you work out.Turn that typical moderately paced 60-minute walk into a 45-minute one, but walk up those three hills that you started avoiding a few years ago. Or change that 30 minute jog into a 20-minute one, but once you're loose, run faster than normal for a good portion of the remainder.One final note: Fast After 50 also covers how proper nutrition and rest impede the aging process. Those sections were not addressed in this article since they are somewhat similar to what's been suggested in this column for years.