Have you ever noticed how runners tend to have flatter butts than people who engage in a lot of resistance training? It’s such an odd thing to think about, but the truth is that spending a lot of time doing cardio, walking, or running on the treadmill can actually give you a flat butt. Why is that?
It comes down to two reasons.
There’s no denying it: running on a treadmill is different than running on the road. When you run on the treadmill, your focus is really about staying in the same place. There’s less forward motion (leaning forward, pushing your body forward, etc.) than there is when running outside.
This change in movement leads to a different recruitment of your muscles. Your thighs do a lot of the work, but the treadmill doesn’t hit your butt and hamstrings as efficiently as they used to. The muscles on the back of your legs (including your butt) are mostly ignored when you run on the treadmill.
But running overall is also less efficient for activating your hamstrings and glutes (the muscles that give you a nice, well-rounded butt). Most of the work is done by your thighs, and it’s only when you hit uphills that your glutes and hamstrings really get work.
Muscle and Fat Burning
This is another downside to doing a lot of cardio work, especially on the treadmill!
Cardio activates stored fatty acids, which the body combines with oxygen in order to produce energy. The more time you spend on cardio, the more your body burns through the fat. Considering that a great deal of your body fat is stored in your glutes, you end up burning a lot of that fat. Even if you notice a decrease in overall body fat, the shrinkage of your butt tends to be most visible.
But here’s the kicker: cardio also leads to a decrease in muscle tone. When you don’t recruit the muscles regularly (through resistance training), the body perceives the inactive muscles as no longer necessary. It taps into the energy stored in the muscles, using it for the aerobic exercise. Muscles only expand when they need to store more energy, and they’ll shrink when they store less energy. Over time, ignoring and underusing the gluteal muscles will lead them to shrink.
What’s the key to running like a bad-ass and still having a great butt?
- Hit more uphills – Incline running and hill sprints focus on your glutes and hamstrings, and they’ll help to recruit those muscles more efficiently.
- Mix in some resistance training – Focus your workouts on your gluteal muscles and hamstrings, doing a lot of Deadlifts, Squats, Lunges, Squat Jumps, and other lower body workouts. Give your butt some strength training love, and it will stay in a beautifully rounded shape!