This combo workout move burns your triceps *and* sets your lower abs on fire

Who doesn’t love a good two-in-one exercise? Doubling up definitely brings on the heat in the moment, but it really pays off in the end. You save time and get great results in the process. While there are plenty of different combination exercises that will make you work up a sweat in record time (hello, burpees!), nothing quite brings on the burn like a skull crusher jackknife workout combo.

Both of these exercises are already challenging when done solo. Skull crushers are a strength-training staple for building up your triceps, and jackknifes zone in on your core, targeting both your upper and lower abs in a way that no crunch could ever. So it’s no surprise that when one of our editors recently did a skull crusher jackknife combo in a group fitness class, she was sore in the best way.

If you want to light up your triceps and core during your next workout, here’s exactly how to do a skull crusher jackknife combo like a pro.

How to do a skull crusher jackknife workout combo

• Lie on your back on a mat. Hold a dumbbell straight above your body with your legs straight up toward the ceiling.
• Slowly lower your legs and arms at the same time. Your legs will hover above the mat, and your arms will stop right above your head.
• Slowly bring your arms and legs back to the starting position, pause, and lift your upper body, performing a crunch so the dumbbell meets your ankles. Perform three sets of 12 reps.

Feel like yoga? Try this five-minute flow that focuses on your core:

Arm dancing is the key to getting ballerina-strong arms, and you can start with these three moves. Then try this 5-move kettlebell workout, straight from a trainer.