Ok, that's it. You can throw out everything I've ever told you about elliptical crosstraining and Dynamic Tension. For I have discovered, hands down, bar none, the best exercise method ever. And it is called Parkour.

Granted, it's insane, it's probably illegal and I'd almost certainly kill or injure myself if I tried it. Parkour is simply the act of navigating a straight line through urban environments using maximum speed. I realize that sounds like, "Oh my gosh you guys, I've just played the most exciting game in the universe! It's called chess!", but think about it. Unless you're running down Lexington Avenue in New York, there aren't a whole lot of straight apertures available in major cities. And if you're trying to navigate in a direction without a road, forget it. There'll be buildings, walls, roofs, parking garages, people, all sorts of things in the way.

Doesn't bother traceurs (Parkour practitioners). Wall? Jump over it. Roof? Barrel roll two stories off it. Person? VAULT OVER THEIR HEAD. And never, ever, ever stop running.

Yes, kids. There is a sport out there for people who want to be Spiderman.

Alas, I am far from being able to parkour (is it a verb, I wonder?), especially this week. While I haven't lost as much weight doing this as I hoped, until this week I haven't backslid either. But lo, one pound. Not earthshattering I know (in fact I'm consoling myself by thinking of it as 1/18 of my cat), but I'm still disappointed. I attribute it to a) stress from figuring out school funds, b) warm weather trips to the Gravity, and c) natural plateau.

This is something that's just going to happen to you sometimes when you're trying to lose weight. The body becomes accustomed to a certain amount of exercise and caloric intake. To get over it, you need to change your diet, do a new fitness regimen, or, if you listen to most of my family, start taking a diet supplement.

I have a whole shelf of these. Every few months or so, some well-meaning relative will give me their nearly full diet pill bottle to try, 'because it didn't work for them, but it might for me.' With such a ringing endorsement, I bet it surprises you that most of these bottles just languish gathering dust in my kitchen. But I wondered if I could find any hard science on these things. And lo, I could...kind of.

Now, there are a million diet pills out there, but basically they all work by following three different mechanisms of action; they can either decrease your appetite, making you burn more  calories, or keep your body from absorbing specific nutrients. Because that’s dry and scientific, and most of the information you get about diet pills is anything but, I’ve made this handy little distinction to help you idenitify the drug mechanism by the kind of advertising it uses:

1. Appetite suppressants. It’s about 6:30 in the evening, you’ve had a hard day and Lifetime is showing either Ever After or Pretty in Pink. You shed your work clothes like a snake, nuke yourself a Lean Cuisine Pasta dinner, get two Michelob Ultras out of the fridge, and settle in for a night of me time. But every time you  start getting emotionally involved in whether Andie and Blane will get together, you’re interrupted by a commercial featuring a formerly fat woman doing one of three things; holding up a pair of jeans the size of a small circus tent, prancing around on a beach in a white bikini twenty years too young for her, or clubbing in Miami with two bald men in shiny shirts.

2. Metabolism enhancers. It’s more like 9:30 now. You’ve moved onto a cup of Jello pudding  and have one of the CSIs on in the background while you’re writing bills. Suddenly the commercials come on. It’s a black screen, with jock rock snarling in the background. You see static shots of various ripped body parts and have the curious sensation you’re watching a commercial for someone auctioning off their washboard abs at Christie’s. Copious sweat is involved. You feel slightly sick. The commercial is ususally ended with a testimonial by the owner of said abs talking about all their energy, whilst freeclimbing a thousand foot butte in the Mojave.

3. Absorption blockers. Now it’s 2 in the morning. You can’t sleep. All the normal stations are playing mid-90’s Law and Order and you’re watching the Travel Channel wishing you had money. This time, the commercial looks like it was made for about twelve dollars. It starts off with a woman looking into the camera and telling you, almost hypnotically, that her diet aid is worth more than your firstborn child. Then it switches to testimonials by users, all of which are accompanied by a small picture of their former, Jabba-like selves in the upper corner. There’s usually a ‘computer graphic’ of some kind (I put computer in quotes because I don’t think something I could have programmed on a graphing calculator in trig class counts), and always, always ends with a ‘but wait, there’s more!’ double offer for some other drug which either improves your memory or sex life.

There you go. Forewarned is forearmed, I always say. But should you take them?

Well, I’m personally very skeptical of the appetite suppressants for a number of reasons. For one thing, I think most people who have weight problems eat from habit rather than hunger, so the drug isn’t really addressing the true reason for the weight problem anyway. For another, even if it does suppress teh appetite, when it comes back you’re going to feel psychologically unsatisfied with a normal amount of food. If you’re hungry, it’s basically because your body is trying to tell you it’s time to eat. Divorcing your eating habits even further from the signals your body sends you doesn’t sound like an improvement to me.

Metabolism enhancers, on the other hand, seem like a pretty good idea. After all, most fitness regimens fail because the exerciser doesn’t feel they’re getting results consummate with their efforts. If you take a metabolism enhancer and sit on the couch, very little will happen. You may lose a little bit of weight, but not much. However, if you exercise while taking them and drop more weight than you were suspecting in your first week at the gym, that might be incentive to go back the second week.

Absorption blockers...I don’t know, they just don’t smell right to me. Even if a drug blocks the fat you’re absorbing from food, that’s hardly the only way you get fat. In fact, I’d wager more weight problems result from sugar and carbohydrates than from fat anyway. And if metabolism enhancers encourage you to undertake healthy behavior, absorption blockers just shield you from some of the effects of unhealthy ones. No real incentive to change or improve the way you eat. Plus, all that fat your body isn’t absorbing...just remember it has to go somewhere. So unless part of your ideation for the new thin you is ‘someone who goes to the bathroom once an hour,’ absorption blockers may not be the way to go.

I know what you’re thinking. “But Sarah, you promised me science! Where’s my science???” Well, to explain why I chose a more anecdotal path for this column, let me present you a little bit of my research;

“Free fatty acid is liberated from lipoproteins by lipoprotein lipase (LPL) and enters the adipocyte, where it is reassembled into triglycerides by esterifying it onto glycerol...In humans, lipolysis is controlled though the balanced control of lipolytic B-adrenergic receptors and a2A-andronergic receptor mediated antilipolysis.”

Hey, wake up! The column's not done yet!

So anyway, that's it. Since I have the bottles, I might try a supplement or two this week and let you know how I make out; I figure it can't hurt any more than the Gravity Reese's Cup Flurries. But I think the thing that's really going to help me get back on track is not having these damn student loans to figure out. And one way or another, that'll all be done soon, and I'll be in Boston.

Preferably leaping over pedestrians and running like I nicked a little old lady’s purse.