Does Indoor Cycling Bulk Up Your Thighs?

You've heard it before — indoor cycling classes will give you bulky thighs. But is that true? Self answers the big debate.

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So, you guys, indoor cycling does cause bulk — but in terms of your calorie burn. Your confidence. Your love of remixes of Capital Cities' "Safe and Sound."

But what it really, truly despite-the-copious-hoopla-from-last-week does NOT do is bulk your thighs.

We were tempted to end our post with that (and this), but we want you to know why your Flywheel class won't give you Hulk legs. So we asked exercise physiologist Michele Olson, PhD, professor of exercise science at Auburn University at Montgomery (and our very own Dr. Abs) to lay it out:

"You have two types of muscle fibers; one type are endurance fibers. When you do aerobic exercise, like Spinning, you use these fibers," Olson says. OK, easy so far. "These fibers can become more fatigue-resistant from doing activities like Spinning and running [aka: it feels easier to do the same workout], but they do not bulk. You have to lift heavy weights, doing multiple sets to cause muscle growth in your power/strength fibers, and you don't use these to any appreciable degree during cardio exercise." Aha! But wait, there's more.

Olson went on to say that recent studies have shown that women actually lose fat from their guts and lower bodies when they cycle often. In other words, their thighs likely look smaller.

Yes, your legs may appear a little pumped after SoulCycle, "but that's temporary, and due to more blood flow and higher blood pressure in the muscle beds in your legs," Olson explains. "You also take up extra water when you sweat a lot, and the muscle beds that are used in any activity will store more water to compensate. But these changes aren't because of increased muscle size or more fat, and they'll fade within an hour."

So! Keep Spinning (and lifting weights and stretching and penning handwritten thank-you notes, because you know they're all good for you). It strengthens your heart, flattens your abs, and burns off tons of calories.

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