One of the newspapers I read runs a recipe-exchange column. So about a week after a plea from Phyllis of Phillipsburg for an easy-to-follow fudge recipe, it prints three or four or five options submitted by other readers.

So why do I based on what I believe and the life I lead regularly read a column about how to make fattening foods like fudge? For the same reason I sometimes watch high-end car auctions on television.You should be able to appreciate the elements of life you don't want or need in yours.But the more pressing question for today's column involves the food editor of this paper. Why does she offer more than one recipe? Why doesn't she simply determine which single recipe is best and print that?Because she doesn't know if Phyllis is allergic to peanuts, prefers butter over margarine (or lard!), or has a deep phobia about using a double boiler, only her town and that the fudge recipes need to be easy to follow.While all this may strike you as painfully obvious (and the bit about the double boiler mildly humorous, I hope), the story suits today's topic: the recent exercise trend toward shorter, more intense workouts.Because you probably learned about the trend through incessant infomercials as I did you may have dismissed it, but the research behind the theory is solid.A 2006 study performed at McMaster University in Canada, for example, found that 30 seconds of all-out stationary bicycle pedaling followed by a brief recovery for a total of three minutes produced health benefits strikingly similar to those procured by easy pedaling for up to 120 minutes.Similar studies producing similar results followed, so it was no surprise when the American College of Sports Medicine recently endorsed a total-body workout that takes 7 minutes to complete.So if there's a way for time-crunched readers to remain healthy in 420 rather than 7,200 seconds, what's left to discuss?Plenty.And it goes back surprise, surprise to the editor of the food section offering multiple recipes because her relative lack of familiarity with her readers. That's why it's foolish for me to endorse what's now being called the minimalist approach to exercise or to condemn it, either.What this column will provide is a primer on FIT, the acronym used in the headline, so that Peter from Parryville, Alice from Albrightsville, and you can understand your options when you create a fitness routine. In essence, there are really only three variables to manipulate: the "F," frequency; the "I," intensity; and the "T," time.Let's say you've spent the better part of the summer building up to the point where you jog without stopping for 30 minutes three times a week. After doing so for the first three weeks of August, you realize that your body and your brain can handle more.So you could continue jogging for the same amount of time, but add a fourth day. In other words, increase frequency.You could continue jogging for the same amount of time and for the same number of days, but run during certain segments of the jog. In other words, increase intensity.Or you could continue jogging for the same number of days, but add 15 minutes to each. In other words, increase time.The recent trend of shortening workouts eliminates your third option, yet depending on why you began jogging that may be the element you want to increase.If you started running as a way to lose weight, shortening your runs and adding intensity makes continuing to lose weight more difficult. While it is possible but tough to burn just as many calories in a shorter run by adding intensity, the type of calories you burn differs significantly.The higher the intensity, the more glycogen (the carbohydrate-created energy stored in your muscles and liver) your body uses to fuel the effort. But as a workout that's less intense goes longer, the body breaks down more and more body fat for energy the stuff you seek to lose.But that's not say that there's no place in your workout regiment for shorter workouts if done the right way.Let's say you've just finished a 10-hour workday on a business trip and realize that there's no way you can do the one-hour heavy weightlifting workout you originally wrote out before your work schedule changed. Here it makes sense to still go down to the hotel's gym, but to hop on a stationary bike instead.After five minutes of a warmup, ride hard for 30 seconds or so and then spin easily for another 15 seconds. Repeat the cycle again and again for 10 minutes. Cool down for five minutes, stretch while you're showering to save time, and treat yourself to room service afterwards.So there is a benefit to super short and rather intense workouts especially for those who have already achieved a high level of fitness but face severe time restraints for a few days or weeks. But since it increases your risk of injury and the odds of exercise burnout, it's not prudent to perform all of your workouts that way.