I just heard from someone (actually about the 357th someone) who is struggling with weight gain while training for a marathon. She's running about 7 hours a week and gaining lovely new butt and thigh cellulite - right on top of her formerly gorgeous quads! With the visible increase in fat and her "benchmark" skinny jeans not fitting anymore, she is confident that her weight gain is actual fat and not water and glycogen in the muscles. That is corroborated by her very low (for a runner) carb intake of about 35%.
She's an experienced marathoner, but I hear from a lot of strength training gym rats who decide to do their first marathon thinking they're going to burn lots of calories and lose fat at an insane rate when they add all that cardio. And then they have the rude awakening. They end up fatter, with less lean mass and less definition. It's such a common occurrence that "how to avoid weight gain during marathon training" seems to be a hot topic on runner's forums.
At first I thought everybody must be going overboard with the calories and carbs, or maybe just packing a lot of glycogen into their muscles. But I've talked to many low-carbing semi-starving marathoners who experienced the same thing. It doesn't seem to make a difference whether they undereat or overeat, whether they gain scale weight or lose it, or whether they still strength train, their percentage of body fat generally goes up. Why is that, you ask? Well, hell if I know. So I asked Alwyn Cosgrove. He says:
I think the adaptation to the activity (ie the metabolism slows down) occurs at an extremely fast rate. So
1) they lower metabolism quicker than they burn calories
2) the activity does nothing to maintain lean mass - in all actuality - it likely reduces lean mass (and lowers metabolism further)
3) The adaptation to running - means that they don't burn as many calories doing it as they originally did.
My other more esoteric idea is the homeostasis one.
When you weight train - you break down muscle -- and the body adapts by growing more muscle.
When you undereat - your body adapts by lowering metabolism in the short term.
When you overeat - your body speeds up metabolism for a short time
When you drink too much water - you pee more - when you don't drink enough - you retain.
The body adapts to any stimulus by doing the reverse.
So when you do an aerobic activity (that burns fat) maybe your body adapts by storing fat?
AC
When you weight train - you break down muscle -- and the body adapts by growing more muscle.
When you undereat - your body adapts by lowering metabolism in the short term.
When you overeat - your body speeds up metabolism for a short time
When you drink too much water - you pee more - when you don't drink enough - you retain.
The body adapts to any stimulus by doing the reverse.
So when you do an aerobic activity (that burns fat) maybe your body adapts by storing fat?
AC
Wow! Crazy thought! Does that mean if you do anaerobic activities like weight training and HIIT that burn a lot of carbohydrate, your body adapts by storing carbohydrate more efficiently and burning... more fat???
But back to the marathoners, it makes sense that your body would adapt to doing the same activity all the time, and that maybe the calories you burn can't keep pace with the damage to your metabolism and lean mass. Alwyn also mentioned a study where people who added 6 hours of aerobic activity a week for a year, lost an average of (drum roll) only 3 pounds (Exercise Effect on Weight and Body Fat in Men and Women. Mctiernan et al. Obesity. June 2007. 15: 1496-1512). Which is why sometimes I want to swat the newbie BFLers who right away want to add tons of moderate cardio to the program. If they'd just follow instructions and throw up a lung for 20 minutes, they'd get even better results. The idea is to get way out of your comfort zone and do something you're really not used to. With Afterburn, for example, not only are you doing the lung-chucking interval training, but he has you do a different cardio activity each workout. He doesn't want you doing the same activity even two sessions in a row, because if you can't adapt, your metabolism doesn't downshift. Combine the variety of intense interval sessions with challenging total body strength workouts and Alwyn's approach for maximum fat loss is the exact opposite of what most marathoners do, which is going easy on the strength training and spending hours per week doing the same moderate aerobic activity.
This whole subject fascinates me. It sounds insane that marathoners would ever struggle to stay lean, and yet I hear from freaked out distance runners all the time. Anybody have any additional insight or experience on this one? Julie? Julie? Anybody? Anybody?
On an unrelated but funny note, I was watching The Simpsons tonight and caught this hilarious exchange between Marge and Homer.
Marge: Oh Homer, you're not fat -- just big boned.
Homer: Marge, nobody gains 30 pounds of bones.
Posted by skwigg
at 9:51 PM CDT
It just is. As soon as I begin to eat higher carbs or to eat sugar..whoa nellie, the scale moves up and I gain fat. I do tend to gain a few pounds in the winter, but I'm ok with that too, it comes back off in the summer. I enjoyed reading the email from AC. Thanks!
Thank Renee!