Being an engineer, I was tempted to snap back that I’d spent four years and a decent part of my potential life’s income learning how to answer those questions. Then, I was afraid that all that knowledge had slipped under the bridge, and I wouldn’t actually be able to answer the question…

Ah, but fear not, readers – the years and the beers haven’t completely eroded Physics 101. In fact, thanks to good old aerobic exercise, I’m likely smarter now than back in college when my exercise regime consisted largely of 12 oz curls.

We’ll start at the beginning, with Newton’s famous

F = M * A

or, Force = Mass times Acceleration.

Rearrange this a bit, and we can see that

Acceleration = Force divided by Mass (A = F / M )

So, off the line, dropping, say, 15 lbs off of a 150 lb frame will make you able to accelerate 10% faster, assuming that none of the weight loss came out of muscle tissue.

There’s a similar benefit to be had in climbing—climbing is just vertical acceleration, with the earth’s gravity trying to pull you down with a constant acceleration of 9.8 meters / second squared. Weight reduction means that you can climb at the same rate using less force where the rubber meets the road.

I’m sure that everyone has heard Newton’s other law about “An object in motion tends to stay in motion until acted upon by an external force”. Well, strictly speaking, that’s true. However, we’ve got plenty of external forces to deal with. There’s wind drag, which we’ll deal with later, but more importantly, there’s gravity.

For those of us in the real world, we really aren’t moving straight forward as we run. In reality, we’re tracing a series of arcs as we push off with one foot, raise our center of gravity up as we push off, experience a brief bit of weightlessness at the top of each stride, get pulled back down to earth by gravity, foot strike, store energy in our legs, and push off again (Yes, yes, Mr. Pose—as much as we try to float our feet in circles, there is still effort involved).

Every time we push off to enjoy that delicious moment of weightlessness in each stride, we’re doing work. In the engineering sense, Work is defined as Force over a distance. In our case, each step involves the work needed to lift up our bodies enough to swap feet, and enough work to overcome hills and aerodynamic drag.

Assuming that drag remains constant regardless of weight (a bad assumption, as cross-section goes down as we get skinny, but I don’t feel like hitting Wikipedia for that one), with each step we’re going to have to lift our body up. 10 percent weight reduction means that each step we’re doing requires 10 percent less work with each step, requiring 10 percent less power (work times time) to maintain a given velocity.

OR, again, with the assumption that you’re not losing power as you lose weight, you can go faster with the same amount of muscles if you’re skinnier.

Picture it this way: Say you lose 5 pounds. Five pounds is about the same as a half-gallon of milk. I were to ask you to lift a thousand half-gallons of milk onto a 6″ stair, you’d think it was a tough, tough task. Losing five pounds is like not having to lift that 500 gallons of milk in every mile you run.
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Editors Note: Whether you should lose weight or not is something you should discuss with a professional such as your doctor or coach. We do not advocate that athletes try to lose weight just to get faster.

According to RW author Amby Burfoot, the table is based on research that runners, on average get 2 seconds per mile faster for every pound they lose. The times you see above are the amounts a runner can shave off his/her race times by losing weight.

Feel motivated?
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Note: Weight loss is for people who are overweight – not for people who are already slim. Losing weight when you are slim means you are losing muscle tissue and that means you are losing strength which in turn makes you slower. If at all in doubt, discuss with a professional (a doctor or your coach).

Six months ago I ran a fabulous 30K and was seriously on top of my running game. I had just come off a hard winter training session and was looking forward to breaking my 5K PR this summer. Then I got a new job. And moved. To another state.

And gained 15 pounds.

My running ground to a halt during the move and adjustments to the new job with extended hours. I knew I had lost some endurance but it didn’t hit until I tried a nice three-mile run. That sweet 9:00 minute/mile long run pace turned into a killer for me and I was wheezing and dying by the halfway mark. It wasn’t that long ago that a 15 mile long run on deep hilly trails was a breeze. Now I couldn’t make it down the street.

And I know who is to blame: Me.

Oh yes, blaming the new job and the move are easy but in my heart I know it’s me. The light dinners I used to eat had turned into giant cheese-globbed full course meals of lasagna, mammoth size steaks, loaves of white bread, and yes, ice cream.

When you are running nearly every day, you burn calories like crazy. A few extra bites of something here and there during the day are easily forgiven on a 10-mile trek through rough-hewn trails or on the pavement. But, if you stop? Your body punishes you for being a lazy butt sloth. It maintains the hunger levels, and begins to store the food. (And I’m not talking about storing it in Hefty bags in the freezer.)

I’m talking about Fat.

But, there is a cure.

It’s easy. It’s the same cure I used when I lost 50 pounds the first time. It’s a special diet. It’s called the “get-your-fat-butt-to-the-gym-you-lazy-idiot” diet. You know this diet. It’s very similar to the “stop-stuffing-junk-in-your-big-piehole-before-it-kills-you-idiot” diet. It’s the one that we know we need to be on, but never want to admit it. It’s when you say, “Diets don’t work,” as you pick up your french fries. I know, I did that too. But I stopped, and you can too.

Here’s What You Need to Do

There are a few ways to fix the problem once you have fallen off the wagon. You can take the approach of visualizing success and getting back to your running prime by surrounding yourself with light and good feelings and applying positive reinforcement of affirming thoughts and self actualization. Yes, well, you could, if you had enough beads and incense.

Lots of people come up with plans and methods and ways to think about how to get back on the wagon but what I found is that none of that will help. Philosophy is not an enabling technology when it comes to running. You need a plan and you need to follow it. Here are my suggestions:

1. Stop eating junk! Take a rubber band and strap it around your wrist and every time you go to pick up a doughnut or danish or giant blob of fudge, snap that sucker so hard you get a giant welt. I’m not kidding. Did it work? Do it 10 times! Good grief. The junk you eat—the doughnuts, the pastries, the candy, the french fries, all of it—is killing you. If you eat these things, you will never return to running. I’m telling you from personal experience. You will never run anything faster than a 35 minute mile. Seriously. Vegetables. Eat them. Your mother was right. You need them for rebuilding the body you had and also to give you something to eat that isn’t fast-food poison. Fiber. Eat that too. You need it (we aren’t discussing the details here, but you need it).
2. Turn your head and cough!. If you are starting up any new fitness program, first make sure you aren’t carrying around a heart attack time bomb in your chest. If you cut out the poisonous food and you die from heart failure anyway, it didn’t do much good. Get a checkup; you probably need one anyway.
3. Get your butt on the road!The only way to start running again is to start running again. Does that seem simple? It is. Can’t run yet? Go walk. You do not need a plan to start; I got your plan right here: 1) put on shoes, 2) leave the house. (Don’t forget the pants though.)
4. Get a plan! OK, so you’ve walked or run for a bit but now you do need a plan. Write down the plan. I found that starting out again does not work by haphazardly going and running every day that you can. You either lose track of your mileage, which can lead to injury from too much too soon, or you don’t make progress because you don’t run as much as you think you have. Write it down. Here’s my plan for next week:
   • Saturday: 4 miles (fast)
   • Sunday: 6 miles
   • Monday: rest
   • Tuesday: 3 miles
   • Wednesday: 7 x 400
   • Thursday: 3 miles
   • Friday: – rest

   There it is. Yours can be harder, easier, whatever, just write it down and track it.

5. Rest! Don’t forget to rest. You cannot start up where you left off if you have been away from running for a long time. Your body is not the same and you need to start easy and rest a little more than you think you should. And what are you doing on rest days? You aren’t running. But you are stretching. “Rest” does not mean TV and pizza. Pizza will kill you and destroy your running. TV just rots your brain. We’re off track, I know. Eat something else and go do something constructive with yourself.
6. Find a race! Very quickly the plan will get old and you will need something else. Find a local race to run in. I know, you don’t like to race or it’s not what you do or your time won’t be as good as before, or waaah, waaah, waaah. That’s not the point. The point is to have a goal to work towards. You will be thinking about the race and gearing your training to that. It will keep you on track. Set it up. Do it. And you get to eat everything you want to in the refreshment tent at the finish.

Here’s Where I Am

I just ran my second race since falling off the wagon. My time was not my best, but it wasn’t my worst. The race is not the point. The race is just to get you moving. My ultimate goal is pull myself back close to my 5K PR time. I want to dump the 15 pounds. I want to be able to run 10 miles and still be able to walk afterwards. And maybe, just maybe, I’ll sign up for another marathon.

Where are you?

Quoting a recent Duke University study published in an exercise journal, Brody notes that while running burns twice as many calories as walking, not all running is equal. Heavier runners burn more calories proportionately than lighter ones. Similarly, runners with poor running form tend to kill off more calories than those far more efficient. However, the unskilled can’t last as long, mile for mile.

“Furthermore, if you walk or run on a treadmill, the aid of the machine diminishes the number of calories your body uses by about 10 to 15 percent of what the machine says you are burning,” Brody writes. On the upside, it’s easier on your body because the machine’s more forgiving than hard surfaces like concrete and asphalt.

How much you eat also is an obvious factor, and this is where some runners run into trouble. We tend to richly reward our hunger after a hard workout, even after taking calorie-dense energy gels and drinks during that run. We also love our carbs, taking in more than we may need for fuel.

If you were to diet without exercise, you’d still lose weight, but you’d also lower your basic metabolic rate—which is determined largely by genetics. That makes it easier to put pounds back on. By contrast, adding running and other weight-bearing exercises to your daily regime boosts that rate.

Cross-training with conditioning activities such as cycling or swimming is needed to tone and strengthen the body, not necessarily add a lot to your overall caloric loss. These types of exercise help avoid injury from overuse and break the monotony if you’re in a rut.

Sure, you might not burn 100 calories in 10 minutes doing all those laps in the pool or gym, but you’ll look better in your clothes—both the ones you wear to work and the ones you wear to work out.

A little more than two years ago, I was on the verge of being fat. Like BMI of over 30 fat. (BMI being the U.S. Government’s measure of big bone-ed-ness). And I didn’t want to be fat. The problem, though, was that I didn’t want to eat well, and definitely didn’t want to give up beer.

So, being an engineer, I realized that I had a pretty well constrained problem: My body was rapidly storing fat, and I did not want to
continue adding fat. In fact, I really, really wanted to part with some of the fat I was carrying. The question was: “How?”

To an engineer, almost every situation in the world can be analyzed by looking at two things—”Conservation of Mass” and “Conservation of Energy.” In approaching a system through a “conservation” framework, the first step is to designate a “closed system”—in this case, the carcass that I haul around associated with my earthly essence.

What Goes In …

The next step is to realize that in a closed system, the total amount of mass in a system is going to be the mass initially present, plus any mass added during the period of observation, less any mass removed. Written in math, it looks like:

Similarly, with energy:

Now, applying this model to myself, I realized that there’s one more equation that needs to be accounted for, and that is that in the body, Mass and Energy are directly related in that one pound of body mass is equivalent to 3,500 calories (or KCal, for folks who actually care about units). Going back to math, we’ve got

Food: More than Just Something to Eat

In the body model, food, even though it has physical presence, is really just a carrier for energy. So, even though there’s functionally
no difference in mass between a pint of bitter and a pint of water, the pint of bitter represents the better part of 200 calories, or a little less than a tenth of a pound of body mass. In other words, the volume and type of food that I ate was largely immaterial—provided that that food had fewer calories than I was expending to get through the day. Most of the food and beverage I consumed did not actually enter the closed system of my body—it always stayed on the side of my mouth, stomach, and intestines that vented to the atmosphere, or was transported via my bloodstream to my kidneys, where it was then pushed
across a membrane and stored for venting to atmosphere. In any case, roughly the same mass of material came out of me as I shoved in my cake-hole.

For an (at the time) 196 pound person, most folks would say that I needed about 2,000 calories a day to maintain (i.e., not gain, or not lose) weight at my somewhat sedentary lifestyle. To lose weight, therefore, I needed to make sure that all the calories I ate
were either less than 2,000, or that I exercised to make up the difference. In other words, I would lose weight so long as:

Simple, right?

Well, I’m guessing that most of y’all reading this realize that it’s not that simple, for the following reasons:

1. Calories sneak up on most of us something fierce. That donut hole or TimBit that won’t hurt? Roughly 60 calories, or, given my tendancy to eat them in threes, about 10 percent of my total calories for the day (absent exercise). Likewise, an extra beer while watching the game is another 10 percent. So, by doing the easy thing twice, I’ve gotten a fifth of my daily calories without any real satisfaction to my hunger.
2. Little bits add up. Sure, I may only be 100 calories over (that’s less than a can of regular soda!). But do that consistently for a month, and there’s another pound on the scale.
3. Blowing off running or hitting the gym needs to be offset in calories. In other words, eating the same on non-workout days as on workout days leads to both #1 and #2 above…

What To Do?

That little bit of engineering made the three points above really stick out. Likewise, it made me realize that progress wasn’t going
to be had in leaps and bounds, but was something I needed to do incrementally. The three rules above work in the opposite way, too,
just like a well-designed circuit:

1. Small cuts add up. Diet Coke, black coffee, or water instead of regular soda? About 120 calories each, or saving about 10 percent of my total calories between lunch and dinner.
2. Little bits add up. A 150 pound person burns about 100 calories a mile, regardless of speed. Park in the far lot from the office and walk a quarter mile each way—that’s 135 calories a day burned back when I was closer to 195 pounds.
3. Doing a big workout can mean a little bit of extra apples in the old feedbag. Within reason. As long as the “gozins” are less than the “gozouts.”

Victory!

It was slow going, but in the first eight months of running consistently and actually caring, about 20 pounds came off without me really having to think about anything. Two years later, and I’m down below 170—still about 20 pounds above where I want to be (150 for my height), but not pushing obesity. Small and incremental change got me where I am. The next step is finding the next tweak to implement and sustain to get me to my goal.