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Half crimp vs full crimp, and how to train crimps for climbing

Frank BlokdijkBy Frank Blokdijk, bouldering coach · Updated

Short answer

A crimp is a small edge you hold with bent fingers. In a half crimp your middle knuckles bend to about 90 degrees and your thumb stays off. In a full crimp your fingers bend further and your thumb wraps over your index finger. It's the strongest way to hold a tiny edge, and it puts the most load on your finger pulleys. So train the half crimp on a hangboard, save the full crimp for the moves on the wall that need it, and train open hand too.

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A crimp is a hold, and a way of holding it

Climbers use the word for both. A crimp is a small edge, sometimes about as thin as your finger pad. Crimping is holding an edge with your fingers bent. Bigger holds get their own names: a jug you can wrap your whole hand around, a sloper you hold open handed, a pocket you put one to three fingers in.

The three hand positions

Position Fingers Thumb Good for
Full crimp Bent hard at the middle knuckle, tips pressed down Wrapped over the index finger The smallest edges, short and hard
Half crimp Middle knuckle at about 90 degrees Off Most edges, and most hangboard training
Open hand Only slightly bent Off Slopers, pockets, rounded edges

Most climbers have one they reach for on everything. If yours is the full crimp, you'll be good on small edges, and you'll wear your fingers out faster than you need to.

How to train crimps

Train the half crimp on a hangboard. None of the finger exercises in Blok Sessions hang in a full crimp. Climbing already gives the full crimp plenty of work, and hanging in it adds the most load for the least gain.

All of these are high risk. Warm up with easy climbing and lighter hangs first, and stop at the first pain in a finger.

On the wall

Take a hold open handed when you can, and save the full crimp for the move that really needs it. Once you're warm, crimp easy problems on purpose: small edges in a half crimp, on ground where no hard move drags you into a full crimp. And leave the full crimp for later in the session, after you've warmed up through open hand and half crimp.

Who shouldn't hangboard yet

In your first year of climbing you don't need a hangboard. Climbing lots of different problems already trains your fingers. If a finger hurts, or you felt a pop on a crimp, see a physio before you train it.

The exercises

  • Max hangs (added weight)

    5 hangs of 10 s on a 20 mm edge with added weight, 3 min rest. Add 2 kg after two clean sessions.

    13 min · High risk · 5 × 10s on, 3:00 off

  • Half-crimp 7/3 repeaters

    3 sets of 6 x (7 s hang, 3 s off), 3 min between sets. Add a set each session, up to 5.

    9 min · High risk · 18 × 7s on, 3s off, 3:00 between sets of 6

  • Open-hand 7/3 repeaters

    5 sets of 6 x (7 s open-hand hang, 3 s off), 3 min rest between sets.

    17 min · High risk · 30 × 7s on, 3s off, 3:00 between sets of 6

  • Three-finger drag hangs

    5 hangs of 10 s in a 3-finger drag at moderate load, 2 min rest.

    9 min · High risk · 5 × 10s on, 2:00 off

Questions

Is crimping bad for your fingers?

No, it's part of climbing. The full crimp puts the most load on your pulleys, so warm up into it, use it when a move needs it, and don't do it out of habit on holds you could take open handed.

Why does my half crimp turn into a full crimp?

Usually because the edge or the load is too hard for you. On a hangboard, take weight off until the half crimp holds for every hang. On the wall, it's a habit, so catch it on easy problems first.

What size edge should I train half crimp on?

20 mm. It's the usual edge, and the one most hang tests use, so your numbers compare. If you can't hold it, take weight off with a foot on a chair or a pulley instead of picking a bigger edge.

What's an open hand?

Fingers only slightly bent, like holding a sloper. A three-finger drag is open hand on three fingers. Most people are weaker in it, which is why it's worth training.