By Col. Michael Panarisi, AEDC/PA
/ Published January 11, 2011
ARNOLD AIR FORCE BASE, Tenn. --
Last week, we explored what was really going on during and after our workouts, but the editors cut me off before I got to the really juicy part..."before" the workout. So, let's review "during" and "after" to see this all fits together.
First, the numbers. A pound of fat stores 3,500 calories. We can burn about 100 in a mile of jogging. We burn around 1,500 a day keeping the system running, and we can all sound sophisticated if we call this our "base metabolic rate."
Since a pound of fat stores so much energy (and we're really rather efficient when it comes to burning it off) the time we spend burning extra calories during a workout is a small (500-ish), though important, part of the puzzle. The real benefit comes "after" the workout. Provided our workout is challenging enough, we will slowly increase our "metabolism," so over time, we burn more all day, not just during the workout.
So what's all the fuss about the "before?" Well, while we can choose to burn more calories than normal by working out, we can't pick where those calories come from. But we do know all the sources, and like so many bodily functions, the order matters. In this case, if weight control/loss is the goal, "running on empty" offers some advantages. Why? It's all about the sources. If you'll allow me another gross oversimplification of what's going on, I'll try to explain.
We have three main sources of energy... muscle stores, blood "sugar," and fat stores. These all meet different needs, and we typically use them in this order: muscle, blood, fat. As we draw one down, the other gets in line, but isn't triggered until we meet certain depletion thresholds. Basically, you are not going to draw down blood sugar until the muscles send in the signals that they are running out, and your body keeps the fat as the "last defense" against starvation. So if you are going to tap into the fat reserves, you have to "burn through" all the muscle stores, and then lower the blood sugar enough to trigger a release of the enzymes necessary to "melt" the fat and allow it to restore (or maintain) blood sugar. So how does "before" matter? Easy...if you start your exercise with a fully charged muscle and blood sugar capacity, you've got a lot of work to do before your body thinks it's starving and needs to release fat. So, if you've eaten recently, and "sugared up," you're in for a long (though enjoyable!) workout. If you don't have the time for that, the secret is the morning routine.
Unless you hail from Transylvania, you probably didn't add anything to your blood sugar overnight. So, for 8-ish hours, your body slowly worked down your blood sugar. Not to a dangerous level, but certainly lower than you'd find it after lunch. So working out in the morning, BEFORE breakfast, gives you a bit of a "head start" on a fat burning campaign. Keep in mind, if your goal is increased performance, or building bigger pecs, you'll have to modify this a bit...you just can't keep up the intensity in the "fat burning" mode, so this "trick" is really only applicable to weight loss campaigns. Plus, most people report a diminished appetite shortly after a workout, so you'll likely eat less at breakfast (bonus!). Only one caveat...the order matters, but so does the intensity of the workout. Just as you can't chose the order of what gets burned, you can't pick the source either...the intensity drives that, and it's all about the Respiratory Exchange Ratio and the consumption/production of Adenosine triphosphate (ATP). Now that REALLY sounds sophisticated, doesn't it? But it's really simple. The more intense the effort, the more the activity will rely on rapidly available energy sources, and fat isn't one. Work out too hard, and fat stays put. Plus, you'll tire more quickly, particularly if you started off low on blood sugar to begin with. So for a dedicated, fat burning effort, you have to pace yourself. Another good reason to use a heart rate monitor. Fat burning is a "sub-70%" event, and it's so much easier to keep that level going if you can read it on the watch. To really get a head start, work your legs a bit BEFORE you hit the stairmaster, and your muscle stores will be out of the way too.
If you find the morning workout fits your schedule best, but want to increase your performance or power through an intense workout, no worries, just take on a few carb calories before you head to the gym. You'll only need a couple hundred, so a granola bar would be just fine. Maybe half an English muffin with a little peanut butter. Just a little something to buffer the drain, and you'll be fine. But if you are in the battle of the bulge, give a pre-breakfast morning routine a try, and when your partner asks you what you're working on, just tell them you are synthesizing some Adenosine triphosphate with a low Respiratory Exchange Ratio!