Cycling, Constipation, and Your Pelvic Floor

Why bike riding might be making your constipation worse (and what to do about it)

If you've ever noticed that cycling leaves you feeling more blocked up, or just "tighter" back there, it’s actually not a coincidence. It’s just physics!

Someone left a comment on my recent reel about bike riding making her constipation worse, and there's a really specific anatomical reason for this that comes down to what happens to your posterior pelvic floor when you sit on a saddle, so I figured it would be helpful to explain...

First, what even is the posterior pelvic floor?

Your pelvic floor isn't one muscle. It's a group of muscles, and the posterior portion sits at the back, closest to your tailbone and rectum. These muscles need to be able to fully lengthen and release in order for you to have a comfortable, complete bowel movement. When they're tight or guarded, things don't move the way they should.

So what does cycling do to the pelvic floor?

A few things, and they all stack on top of each other:

The saddle puts direct, sustained pressure on the soft tissue around the back of the pelvic floor for the entire ride. That prolonged compression causes the posterior pelvic floor muscles to brace and guard. They're essentially in a low-grade holding pattern the whole time you're riding.

At the same time, cycling keeps your hips in constant flexion. You never get the full hip extension that you'd naturally move through when walking. That full extension is part of what keeps the pelvic floor mobile. Without it, the posterior muscles miss their natural lengthening cycle, and they stay shortened.

Add in road vibration (which triggers constant subtle bracing responses through the whole pelvic floor), plus glute compression against the saddle (which means the glutes aren't doing their job properly, so the deep posterior floor muscles pick up the slack), and you've got a recipe for a back there that is chronically tight.

Why does that make constipation worse?

Because a tight posterior pelvic floor physically resists the opening and releasing motion your body needs to empty properly. The muscles meant to coordinate that release are braced, and braced muscles don't let go easily.

This is exactly why I always say: you cannot strengthen your way out of this. If these muscles are already holding too much tone, adding more activation work (Kegels, core exercises, anything that loads the pelvic floor) makes the problem worse, not better.

So what should you do?

Here are some practical things you can do that make a real difference:

Check your saddle position. If your saddle is uncomfortable, your body will automatically tuck your tailbone under to compensate, and that posterior tilt is exactly what drives more tension into the back of the pelvic floor. A good saddle, set at the right height, lets you sit with a slight anterior tilt (think: tailbone gently untucked, a small natural curve in your lower back). You should be able to feel your glutes and hamstrings lengthening as you pedal, not gripping.

Put your mind to your glutes. This sounds simple but it works. Actively cue your glutes to push down through each pedal stroke. If your quads are doing all the work, or your lower back is aching after rides, that's a sign your glutes have checked out and your pelvic floor is picking up the slack it shouldn't have to carry.

Breathe properly while you ride. Deep diaphragmatic inhales and exhales, the same way you'd breathe during pelvic floor work. The diaphragm and pelvic floor should move together, so shallow chest breathing during your ride keeps the whole system braced.

Alternate between sitting and standing. Regularly shifting out of the saddle gives the posterior pelvic floor a break from sustained compression and lets the hip flexors cycle through more range. Even short intervals standing on the pedals make a huge difference.

Move your hips after you get off the bike. Some gentle hip flexor lengthening and posterior pelvic floor release work immediately post-ride can interrupt the tension pattern before it sets in.

And if the tightness is already well established, that's where the deeper release work comes in. Diaphragmatic breathing, posterior pelvic floor release techniques, and addressing the hip flexor tightness that's feeding the whole pattern. Once the muscles can actually lengthen on demand, the constipation piece often improves dramatically, sometimes faster than people expect!

This is the exact pattern I work with inside the Tight Pelvic Floor Fix, because pelvic floor tension is one of the most overlooked drivers of constipation in women, and it's also one of the most fixable.