Being in my mid-to-late-twenties, the effects of a slowing metabolism has been creeping up on me for a couple of years now. Just last Christmas, when I found myself weighing at 140 pounds — an astounding 25 pounds more than I was just a year and a half ago. I felt grossed out with myself when I saw the holiday pictures — never have I seen my face to be that chubby before!

(Before you get jealous that I was “only” 140, keep in mind that I’m a short guy — my height is 5’3”. So if you calculate my body mass index, that easily puts me at the Overweight category.)

That’s when the first “snap” moment happened, and I decided to take my health more seriously than ever. Gone are the college days when I could drink a six-pack of beer and have pizza for dinner everyday and never gain weight. I had to do something, and fast.

I took on a serious diet and drastically cut down what I ate. Because I took working out pretty seriously back in college, I knew that I should be working out — but I didn’t. True enough, I did shed quite a few pounds after a month or two and got back down to 130.

Then I went on a 3-week vacation in April.

I’m sure you know how it goes: you’re too busy to even THINK about working out. You’re eating out all the time and don’t give a damn whatsoever about calorie control. Hell, drink all the beer that you want — life is short so live it drunk!

When I got back, I shot back up to 136 pounds. In just 3 short weeks.

I KNEW that if I wanted to drop the pounds and keep them off for good, there really was no way around it; I was going to have to buckle up, bite the bullet, and *gasp* run.

My weight regulated down to around 132-134 pounds after that, but I still looked bloated. I still didn’t like the way I looked in pictures. So after having another “snap” moment, I put on my shorts and shoes, grabbed my brother’s iPod (my Zune broke while I was on vacation) and went on running.

It was difficult at first, but I managed to get that workout under my belt. I’d run an average of 3-4x per week; sometimes running only 2, sometimes going as much as 5 workouts — depending on my motivation level. I was also going through some personal issues at this time, and I found that running was an excellent way to forget all my problems at least momentarily.

A month or two of dedicated myself to running so I could lose weight, and I found myself down to 125 pounds.

The moment of truth came when I went on another 3-week vacation. Except this time, I only gained 2-3 pounds after I got back. Not to mention, my friends complimented me on how much healthier I looked, not just on how much weight I lost.

Because of the way that weight loss works, the weight loss you get from exercise is much more permanent than any prolonged period of dieting will give you (you can read here for my take on why weight loss from running and exercise is better than a short-term diet).

Scientifically speaking, energy is what our bodies burn to keep it going on a day to day basis. This energy comes from the food that we eat, which has a certain calorie amount which is basically a unit of measurement for energy. Even without exercising, your body burns energy to keep its systems functioning — this is called the basal metabolic rate (BMR), or how much energy is burnt when the body’s at rest.

If your BMR is 2,000 calories (meaning you burn 2,000 calories everyday without exercise), and you take in 2,000 calories in food every day, your weight will stay the same.

If you take in more calories than your BMR, what does your body do with the extra calories? It turns it into fat — thus, you gain weight. If you take in less calories than your BMR, your body has to find other sources of energy to burn — and since fat is nothing but stored energy, you burn fat.

Simple, right?

Now, because you’re reading this site, I assume you’re interested in losing weight and shedding those extra pounds that you got around your waistline or burning off that cellulite on your thighs. With that said, I’m going to assume that common sense and basic arithmetic can tell you that in order to lose weight, you have to create a calorie deficit, in one way or the other.

How Exactly Does Running Help You Lose Weight And Burn Fat?

Simply speaking, running helps you to lose fat and keep it off permanently (at least, more permanently than a short-term diet) is by conditioning it to burn off more calories on a daily basis than you currently are.

That means that instead of decreasing your daily calorie intake (which slows down your metabolism), making running a constant habit trains your body to burn more energy and ends up speeding up your metabolism. And based on my informal research, it is MUCH easier to improve an “okay” metabolism than to fix a “broken” one.

Truth be told, the benefits of running and cardio doesn’t happen during the workout — the magic happens AFTER. By making running a habit, your body is slowly getting used to burning more energy throughout the day, increasing your BMR and actually allows you to eat more than you usually do!

This is exactly why I believe that running (or some form of cardio training) is a great idea for those who want to lose weight, even if they are complete beginners and have never been much of a runner before.

Why Can’t You Just Eat Less And Skip The Workout?

You can. A calorie deficit is a calorie deficit, whether you’re doing it by running to lose weight or eating less calories. But let me tell you the two reasons why I don’t believe it to be a sustainable method to burn fat and lose weight.

The first reason is that you can’t guarantee that you’re going to eat that amount forever. Most people are unsuccessful in maintaining a diet based on creating calorie deficits, and end up reverting to their old eating habits. This is called yo-yo dieting, and even Oprah blames her up-and-down weight gain with yo-yo dieting and a lack of exercise.

Second reason, and perhaps the more important one, is that while you’re starving yourself, it triggers your body’s natural famine response. Basically, it thinks that you’re going through some sort of famine/starvation period. It starts to get calories from your muscles instead of your fat storage.

And when you do go back to your old eating habits, the body thinks, “I better stock up on energy for the next time this famine happens!” and stores ALL extra calories as fat instead of distributing them to both fat and muscle.