My sister swears it’s true — and I must say, her butt does look bigger since she started spinning classes a few months ago.
If this is a myth, as most fitness instructors say, it’s a fairly prevalent one — googling that question generates more than 2 million responses. A friend who’s a pretty serious cyclist — and actually wishes her backside had a bit more shape — says she’s never noticed an increase in size, just muscle tone. “My former personal trainer assures me it’s a myth,” she said.
The problem, if there is one, likely comes from the resistance dial.
“To build the large quadriceps and glueteal muscles you fear, you’d have to use a very difficult gear for repeated and extended periods of time,” reads the answer to this FAQ on spinning.com. “During Spinning class, climbs usually don’t last for more than a few minutes—not enough time to (build) bigger legs or a bigger butt.”
Mike Cola, a personal trainer and gym owner who runs fitnesscontrarian.com, has heard this complaint often enough that he’s formed a theory about it. According to Cola, what may be happening to some highly motivated dieting spinners may be an inadvertant form of glycolitic super-compensation, a body building technique used to increase the size of muscle cells.
“This is what I think is happening to some of my clients and their friends who think their legs are getting bigger from spinning,” Cola wrote. “They are most likely eating very little to watch their weight and spinning class is depleting all their carbohydrate stores. Then after one too many spinning classes, they get ravenously hungry and over eat. Their legs then get primed for increased carbohydrate storage, which results in bigger legs.”
I don’t know about that. But I do know that in the one spinning class I attended, Traci definitely was twisting that resistance knob more turns than anybody else in the room, including me. After comparing notes with one of her instructors recently, they decided she ought to focus on more speed, less resistance.