Why do the forearms pump out — and how to rest, shake out and pace on the rope to survive long routes instead of dropping off halfway up the wall.
The direct answer to the most-asked question: your forearms "pump out" because under continuous tension they build up metabolic by-products faster than they clear them — at some point you can't close your hand any more. The way out isn't just more strength but resting, shaking out and pacing cleverly.
And something else important: under fatigue it's technique that breaks first, not strength. Tired climbers perceive their options on the wall worse and move less economically. Meaning: manage the pump and you not only last longer but climb cleaner all the way to the top.
Interval climbing is largely aerobic work, and the recovery between moves decides. That's exactly what you can steer actively on the route — with the techniques in this guide.
The pump isn't a sign of weakness but of oxygen shortage and metabolite build-up in the working muscle. It comes faster the more you hold on unnecessarily. So the first lever isn't more strength but wasting less strength.
The art is to hang on the skeleton, not the muscle: arm straight, weight into the bones, hip into the wall, load on the feet. Look for no-hands rests, corners to stem in, or knee bars. Every second of offloaded forearms is gifted climbing time.
On a good hold you shake out the free hand — loose, fingers open, let the blood flow. A well-known trick is the G-tox: alternately raise the hand above your head and let it hang so fresh blood reaches the forearm. Swap hands before the holding hand itself shuts down.
On easy sections climb smoothly and briskly to save strength, at rests deliberately downshift, before the crux gather briefly. Don't panic-rush and don't linger on bad holds. The route has a rhythm — find it.
Hold every hold only as hard as necessary, not as hard as possible, and keep breathing evenly. Clenched gripping and holding your breath are the fastest pump accelerators. Staying loose is trainable — and saves more than any extra pull-up.
Resting doesn't mean hanging forever in one spot until you drop off there — find the balance between recovery and progress. If a rest position gives nothing, climbing on is often the better choice.
And while saving strength, don't forget the clipping: better to rest briefly at a good hold and clip the draw than to rush on exhausted with lots of slack. Recovery and safety go hand in hand at the same good holds.
Learn your rest positions during route reading from the ground — mark every good hold in your mind as a filling station before you set off. Knowing a no-hands rest comes in three moves lets you climb the hard section before it much calmer, because the head has a target.
Half of endurance sits between the ears: a planned rest works twice as well, an unexpected one is often missed.
Because under continuous tension metabolic by-products build up faster than your body clears them — the muscle "over-acidifies" and shuts down. It's sped up by gripping too hard, bent arms and tension. So the lever is less wasted strength: straighten, offload, shake out, grip loosely and breathe calmly.
Hang on a straight arm on the skeleton rather than the muscle, bring the hip into the wall and the weight onto the feet. Look for no-hands rests, corners or ledges and shake the hands out there alternately. The key is finding the rest before you're completely shut down — not only when nothing works any more.
Shaking out means loosening the free hand and letting the blood flow. With the G-tox you alternately raise the hand above your head and let it hang — the change is meant to flush spent blood from the forearm and bring in fresh, oxygen-rich blood. Swap hands regularly before the holding hand itself shuts down.
Hold every hold only as hard as necessary, climb with straight arms and bring your weight over the feet and hip into the wall. Smoothly through easy sections, deliberately rest at good holds, don't forget to breathe. Saving strength is largely technique and head — not just a question of muscle.
Sport Climbing: Redpoint and Projecting