Guest blogger Robin says: As I was plugging along on the treadmill (at a very high incline, I might add), one of my favorite trainers said: "You burn about 300 calories a day just doing nothing."

HUH? So why the hell was I killing myself for the last 40 minutes to burn a measly 400 calories?

Simple. I'm trying to lose weight. To lose one pound a week (the medically recommended amount to lose for sustained loss), I need to burn 3,500 calories each week. Sure, I can do that through diet alone, but it's fairly tough to cut 500 calories every day. That giant bagel you're chomping while you're reading this probably has about 400 calories (if you add cream cheese, you could be looking at more than 500 calories). So what's a mom to do?

Get moving.

It's true. Your body's metabolism uses calories around the clock for your everyday bodily functions. So, even if you DO burn 200 or 300 calories just by being alive (and that's a high estimate for a relatively active, fit person), you're still not gonna drop any weight if you don't get moving.

It's hard to fathom how your body burns calories at rest. And truth be told, it's not the same burn rate for everyone. In a nutshell, the higher your body's muscle-to-fat ratio, the more calories you burn--even at rest (this is called your resting metabolic rate). The best way to determine your resting metabolic rate is to have a body composition test performed by a fitness expert (your local gym or YMCA is a good resource).

The more muscle you have, the more calories you burn. Which is why my fave trainer gets to burn a ton of calories while she watches ME work out. So be sure to add weight training to your exercise regimen at least twice a week. You also can experience a type of "after burn" in calories after a workout. However, experts are divided on exactly how many calories you continue to burn once you leave the gym. Some say 10 to 15 extra calories an hour for about 2 hours post workout--others say as much as 15 PERCENT more calories. With the research on this topic so sketchy, I wouldn't count on after burn to help with weight loss.

Regardless of your resting metabolic rate and any potential after burn effects, you still need to dump 3,500 calories a week to see the scale go down to the next number. The best way: Watch your food intake, but don't stress over it. The more you restrict yourself, the more you're going to freak out and eat way more than you need. Think I'm kidding? People who deprive themselves of the foods they love tend have an all-or-nothing approach to their diet. That means that if they have, say, one little cookie, they figure they've blown it so they keep eating the crap.

Moderation really is the key. And exercise is always a nice addition. If you can burn 350 calories on most days of the week, and cut back on your calories here and there, you'll likely lose a pound a week--and since it's a gradual, slow weight loss, chances are you'll keep it off.