V-ups: how to do them, easier and harder versions, and what the studies measured

A V-up is a crunch and a leg raise in the same rep. You start flat on your back, arms reaching past your head, and lift your top half and your straight legs at the same time until your hands reach toward your feet and your body folds into a V. Then you lower both ends slowly and start again.

Because the legs lift too, it asks more of the hip flexors, the muscles on the front of the hip, than a crunch does. This page covers the steps, the faults, what the studies measured, the easier and harder versions, and the sets. The held version, the V-sit, is here too.

How to do a V-up

1. Lie on your back with your legs straight and together and your arms straight overhead, resting on the floor behind you.
2. Brace your midsection and press your lower back toward the floor.
3. Lift everything at once: raise your arms, head and shoulders and your straight legs together, reaching your hands toward your shins or feet.
4. Balance on your seat for a moment at the top, body in a V.
5. Lower slowly, both ends together, until your shoulders and heels are just off or lightly touching the floor, then go again.

Breathe out on the way up. These cues are practical, not study findings.

The common faults, and a fix for each

• Throwing the arms. Swinging your arms up to get the rep done turns it into momentum. Slow the lift until your trunk does the work.
• Only one end moving. If your legs shoot up and your chest stays down (or the other way round), you're doing a leg raise or a crunch. Lift both at the same speed.
• Lower back arching off the floor as the legs come down. Stop the lowering higher, or bend your knees.
• Crashing down. Control the lowering; it's half the rep.

What the V-up trains

Every study here is a short lab measurement of muscle activity (electrical activity in the muscle, not growth). None trained anyone for weeks.

• The V-up against a crunch. In 21 people holding each position, a supine V-up, a crunch and four face-down "V-up" versions on equipment showed no significant differences in the upper or lower front abs (the rectus abdominis) or the external obliques. The internal oblique was more active in the supine V-up than in the slide-board version, and the hip flexor measured on the front of the thigh, the rectus femoris, was less active in the crunch than in any of the other five.¹
• The V-sit among twelve exercises. In 20 physical education students doing twelve ab exercises, the V-sit exercises and lifting the legs while hanging by the hands produced significantly more activity in the lower part of the front abs than all the others.²
• The v-sit among five exercises. In 25 healthy people, the v-sit and a reverse curl produced the most activity in the external obliques, and a plain trunk curl, a trunk curl with a twist, the reverse curl and the v-sit produced similar activity in the upper front abs.³
• The V-sit held to failure. In 17 healthy young adults, 12 men and 5 women, holding four exercises until they couldn't, the V-sit asked very little of the shoulder (middle deltoid activity about 2% of a maximal contraction, against about 43 to 56% in a front plank and a raised side support), and the authors describe it as isolating the abdominal part of the trunk and hip muscles they measured.⁴

Read together: in these small studies the V-up and V-sit worked the front abs about as hard as a crunch, sometimes harder in the lower part, and brought in the hip flexors more. More activity during a rep isn't proof of more benefit over weeks.

Easier V-ups

• Tuck-up: the same move with your knees bent, pulling them toward your chest as you sit up. Bent legs are a shorter, lighter lever.
• Single-leg V-up: one straight leg lifts at a time, the other stays on the floor; switch legs each rep.
• V-sit hold: sit, lean back, lift your feet and hold the V without moving. Start with your knees bent and your hands on the floor beside your hips.

No study comparing these versions with the full V-up turned up in a PubMed search for this page, so they are practical steps, not measured ones.

Harder V-ups

• Slower: three seconds down, a one-second pause at the top.
• A light weight held in both hands, a plate or a dumbbell, once fifteen clean reps come easily.
• Hold the V: stay at the top for a few seconds before you lower.

These are practical, not compared in the studies above.

V-ups, crunches and the hollow hold

The crunch moves only your top half and is the lighter, simpler curl. The reverse crunch moves only the bottom half. The V-up moves both at once, so it's harder and uses the hip flexors more. The hollow body hold is the same shape held flat, with your lower back pressed down, and is a good way to learn the position before you add the fold. Bicycle crunches add a twist instead.

Sets, reps and where they go

• Two or three sets of 8 to 15 slow reps, each stopped a rep or two before your form breaks, with about 60 seconds of rest.
• For the V-sit hold: two or three holds of 15 to 30 seconds.
• At the end of a session, after your main lifts, in the "curl forward" slot of the core workout, in place of the crunch.
• Progress one thing at a time. (Progressive overload covers the options.)

These numbers are practical, not from a study.

Common questions

Do V-ups work the lower abs?

In one study of twelve exercises, the V-sit exercises and a hanging leg lift produced more lower front-ab activity than the other exercises,² but in the V-up study above the upper and lower front abs showed no significant differences between the V-up and a crunch.¹ The front abs are one long muscle, and these small studies don't settle how far you can single out one end of it.

What's the difference between a V-up and a V-sit?

A V-up moves: you fold up into the V and lower back down each rep. A V-sit is the same V held still, balanced on your seat.

What if my back or hips hurt?

If you have pain, an injury or a medical condition, a doctor or a physical therapist should set the limits before you train; this page is general guidance for healthy adults.

If you'd rather have the week planned

Ab exercises are easy to list; fitting the right one into a week that already has squats, presses and pulls is the part a page can't do. Coaching is the version where your workouts live in Trainerize, built around the days and the equipment you actually have, and a weekly call looks at how the week went and sets the next one. Coaching for beginners explains how the first weeks work, and apply is the first step. Otherwise: at the end of your next session, do two slow sets of V-ups and write down the reps.