The bicycle crunch looks easy. You lie on your back, move your legs like you’re pedaling, and throw in some twists for the abs. Simple, right? That’s what I thought, too—until I realized I was doing it all wrong. My neck hurt, my core wasn’t sore, and worst of all—I wasn’t seeing any results.
If you’re putting in time and energy doing bicycle crunches, you wanna make sure you’re doing them right. This move is one of the best for hitting both your upper abs and obliques, but only when your form is on point.
Let’s go through the top 5 mistakes to avoid when doing bicycle crunches and how to fix them so you can start feeling that real ab burn where it counts.
Mistake #1: Pulling on Your Neck
This is the one I see most often—and yep, I’ve been guilty of it, too. When your core starts to fatigue, it’s super tempting to yank on your neck to help you crunch up. But doing that only strains your neck and takes the focus off your abs.
Why it matters: You’re not working your core anymore. You’re just overusing your neck muscles, and that’s not the goal. You’ll probably finish the set feeling sore in all the wrong places.
How to fix it:
- Keep your hands lightly behind your head, like a pillow—not a grip.
- Elbows should stay wide, not squeezing in toward your face.
- Use your core to lift your chest, not your hands pulling your head forward.
Try looking up at the ceiling during each crunch to help keep your neck in line. It sounds weird, but it works.
Mistake #2: Going Too Fast
We’ve all done it—zooming through bicycle crunches like we’re in a race. But speed doesn’t mean better results. Going too fast usually means you’re using momentum, not muscle.
Why it matters: You won’t engage your abs fully if you’re just flailing your legs and twisting fast. Plus, fast reps often come with sloppy form, which increases your chance of injury.
How to fix it:
- Slow it down. Try doing a 2-second hold every time your elbow meets your knee.
- Focus on squeezing your obliques (side abs) with every twist.
- Think about quality over quantity. It’s way better to do 10 good reps than 30 half-hearted ones.
I like to do these to a count—“1-2 squeeze, 1-2 switch.” Makes it feel like a rhythm, not a rush.
Mistake #3: Not Extending the Legs Properly
The leg movement in bicycle crunches is just as important as the twist. One mistake I made early on was bending my knees too much or not fully extending my legs. It made the move way easier—but way less effective.
Why it matters: When you don’t extend your leg, you’re taking pressure off your lower abs, which defeats the purpose of the move.
How to fix it:
- As one knee comes in, the other leg should extend out straight—like you’re reaching your toes toward the wall.
- Don’t let your extended leg drop too low or rise too high. Keep it about a few inches off the ground.
This leg movement is where a lot of the burn comes from, so make it count.
Mistake #4: Twisting the Elbows, Not the Torso
Another sneaky mistake is twisting the elbows to make it look like you’re crunching, instead of actually rotating your upper body. I used to try to “touch” my elbow to my knee by just moving my arms—no real core engagement.
Why it matters: If you’re not twisting through your core, you’re missing out on those oblique gains. You’re just swinging your arms.
How to fix it:
- Keep the elbows wide and locked in position.
- Focus on turning your shoulder toward the opposite knee, not just your elbow.
- Think of it as a chest rotation, not an arm movement.
One thing that helped me: imagine your ribs turning, not your arms. That mental cue made a big difference in actually working my side abs.
Mistake #5: Letting the Lower Back Arch Off the Floor
This one might not be obvious right away, but if your lower back lifts off the mat, your form is off—and your core isn’t fully engaged.
Why it matters: A flat lower back helps you brace your core, which is what you need to actually work your abs and keep your spine safe.
How to fix it:
- Before starting, press your lower back into the floor and keep it there the entire time.
- If you can’t keep your back down while extending your leg, try keeping the extended leg a little higher.
- You can also place your hands under your glutes for support if you’re just getting started.
If you feel your back arching, pause, reset, and slow it down. It’s not about knocking out reps—it’s about keeping control.
Bicycle crunches are one of the best core exercises out there, but only when your form is solid. I used to fly through them just to check them off my list, but now I slow it down, focus on the twist, and keep that leg extension strong. The difference? Way more burn—and way better results.
Next time you’re on the mat, try paying attention to these five details. Your abs will light up, your form will feel cleaner, and you’ll actually get the most out of every rep. No more wasted effort—just pure core fire.
