People often take up running as a weight loss tool. And for many it helps. Until it doesn’t. Aside from the previously discussed myth that exercise alone produces weight loss, there is another interesting facet to this idea: after a certain point that seems to be individual to each body, adding mileage can actually produce weight gain. This well-documented phenomenon, often referred to as “the marathon 10” for the 10 or so pounds people often gain while training for a marathon, has long presented a conundrum for new and seasoned runners.

I remember as a newbie runner hearing glorious tales of being able to eat anything you wanted – White bread! Pasta! Candy! Carbs to your heart’s content! – while in the fabled land of Training. I soon discovered for myself that this wasn’t true when I quickly gained five pounds back from my hard-lost baby weight. For myself, it seems I can run two or three miles a day and even throw in an occasional longer run of 6-9 miles without any adverse affect. But anything over 10 miles seems to kick the cravings up from “merely irritating” to “completely unavoidable.” Take my 3.5 hours of cardio two weekends ago: the scale immediately went up 3 lbs and has stayed there ever since. There goes the water weight theory. Sigh.

Jane, a good friend and seasoned marathoner, agrees. “I never go into training for a marathon thinking I’m going to lose weight. I normally don’t eat a lot of carbs but when I train I can’t run unless I eat a lot of them. My last three marathons I’ve gained 11 pounds every time. And it’s a b*tch to take off too.”

Gym Buddy Megan, who is training for the Twin Cities Marathon October 7th (go Megan!!), has also experienced some weight gain although closer to 5 pounds rather than 10. Unlike J, she was surprised by the weight gain. “Honestly, I think it’s because I’m eating more carbs and eating more on days I’m not running. I think I’m just hungrier.” She adds, “I can really see it in my stomach so I don’t think it is muscle.”

On the other hand though, Reader Gretchen 6-time veteran marathon mama (also running Twin Cities this year!!), says that she typically doesn’t see any weight gain. She doesn’t really lose weight either but says her clothes fit better as she loses fat and gains muscle. “However,” she adds, “I’ve been really careful to count my calories and track my eating. My problem is after I finish the race, I usually gain weight because I’m not running that much anymore but I’m still eating like I am!”

But It’s Not Fair!

As to why this happens, there are several theories:

1. Biological: The body becomes accustomed to high-volume moderate-intensity endurance training and starts banking fat – it’s primary fuel for such long runs – in preparation.
2. Psychological: You think you are torching massive calories but due to your body acclimating and our natural tendency to overestimate calories burned, you overeat. Or, as I like to think, “Come on! I earned this ice cream!!”
3. Physiological: Running that much triggers some kind of mechanism in the body that kicks cravings, especially for simple carbs, into overtime. It hits you hard since you’ve already expended your willpower on getting through that 20-miler.

I’m guessing it is probably a combination of all three factors. Not that that makes anyone who is haunted by the marathon ten feel any better. But at least you know you’re not alone!

There are lots of avid runners (and bikers) reading Frugivore. Any of you experience weight gain or weight loss as a consequence of long endurance activity? What do you think caused it? And is completing a marathon worth it?