Is Running Making You Fat?

Once upon a time, I could run every day. I was rarely sleep deprived, ate as much as I wanted and enjoyed long, scenic runs through the fields of Grantchester. Life was good.

Then I joined the world of private equity and my 15 hour work days led to a 10lb weight gain. Exhausted and burned out, I brought up the idea of working out in the evenings to a female manager. “You shouldn’t even dream of leaving your desk this year. Unless, of course you want to go in your own time before work.” Sadly, my “own time” consisted of a 7am-8am slot which, after nights that often ended at midnight in the office, was none too appealing. A year flew by, my hours improved, and I began squeezing in evening trips to my company’s luxurious gym and coming back to the office for dinner and more work.  The weight came off, my energy came back and heck I ran a half marathon.

All this running and I never really took to the treadmill. I’d found a spectacular run along the banks of the Thames and used it as a motivator to get me through those painful Sundays in the office.  I ran through Hyde Park in the mornings, through Regent’s Park on the weekends and through whatever city park I could find during European business trips. I ran whether I was tired, sick or upset. I ran through rain, snow, hail and heat (and in the case of my first half marathon, all four). I ran until I moved to New York and discovered that it just wasn’t fun to run outside anymore. Boo.

Now that I’m in San Francisco, I’m starting to run more regularly again, albeit at a gym.  While I’m still getting the “endorphin high” and that strange twitching if I skip a day, I’ve definitely noticed that I’m NOT losing any weight. In fact, I may even be *gasp* gaining some! Now, I have to note here that outside of shedding some initial weight, running has never made me thinner, but is it possible that running ON A TREADMILL can actually make you fat?

We all know that cardio makes you hungry and it’s easy to overeat when you think you have a license to indulge a teeny bit more, but I wonder if there’s something more fundamental at play here. We’ve all seen them – those poor, exhausted souls who run all the time, yet never seem to lose any weight. Are they fat because they run too much??

The Metabolism aka “Skinny Fat” Theory:
According to Gym Spy, Ryan, YES running can make you fat. Excessive cardio eats away at your muscle mass and actually lowers your metabolism, making you “skinny fat”.

“When you run at the same pace for a long time, your body needs energy to keep going. So it turns to the best source … not only your saddlebags but your lean sexy muscle. And since it takes calories and energy to keep muscle, the more muscle you lose the slower your metabolism. If you used to burn 1,800 calories a day doing nothing, you may now only burn 1,600 calories.”

Isaiah White, Florida fitness instructor, echoes this theory, while the author of this fantastic article explains in scary detail how running can actually turn your body into a “fat storing machine”.

The Exercise Efficiency Theory:
“Regular running improves exercise efficiency, meaning that you burn progressively fewer calories while performing the same amount of activity. If you run for 30 minutes three times a week at the same speed on a treadmill, you’ll be burning fewer calories one month later. If you’re still doing the same pathetic half-hour treadmill jog ten years later, you can imagine how efficient you’ll have become at running, but how inefficient you’ll have become at burning fat.”

The Testosterone Theory:
An interview with nutrition and supplementation expert Dr Eric Serrano reveals that combining low carbs and traditional cardio will burn fat in the muscles but not subcutaneous fat, which is found in the belly and legs.  He says “the more cardio you do, the lower testosterone levels will be. And cortisol will increase, which is responsible for thick abdominal fat and lower body fat in women.” Oh, grrreat.

The Primal Health Theory:
Another great read is “a case against cardio” where Mark Sisson argues that we are simply not biologically suited to long periods of high-intensity aerobic exercise. It is much better, he says to build aerobic capacity slowly and steadily, training your body to derive more energy from fats (and not glucose) and building muscle with occasional quick bursts of speed and intensity.

All pretty interesting stuff, especially when you consider the amount of brainwashing we’ve experienced around the unlimited virtues of running. Is cardio activity really just a creation of the fitness industry? Are we biologically unsuited to running long distances and raising our heart rates to ridiculously high levels?

Weight loss / gain aside, there are still many, many benefits to running though and I enjoy it too much to give it up.  If you love running, but also want to lose weight, you should couple it with resistance, strength and interval training. All of the above can boost your resting metabolism, tone and lengthen your muscles and keep you challenged. But that’s a post for another day!