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Melting Off Holds? Then Train Local Endurance

Getting pumped on a grade that within your limits? Then you lack Local Endurance. The good news is this simple training plan will address that weakness and have you hanging on virtually forever.

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This is part one of our five-part series, Learn to Train: A Complete Guide to Climbing Training.

The Problem

Climbing a route below your limit still feels pumpy, or you have trouble recovering in the middle of a route, even while resting on a jug or climbing easy terrain.

The Solution

Train local endurance with ARC sets to climb longer and recover more easily.

How it Works

Local endurance is your ability to stay on the wall for long periods of time at a certain grade. The main benefit is that it raises the difficulty level at which you can rest. If you can climb 5.10 without feeling pumped, then reaching a section of 5.10 climbing after a crux provides an opportunity to shake out and recover. You’ll feel fresh for the next hard section. However, if you lack this level of endurance and reach the next crux dog-tired, you’re probably in for a ride.

Though a 5.12 climber might find 5.10 routes easy, that doesn’t mean he can climb 5.10 indefinitely. It just means he’s not that pumped by the end of any single 5.10 route. A high level of local endurance means that climbing below a certain grade for up to 45 minutes at a time, or even longer, won’t get you pumped.

Local endurance is a muscle group’s ability to sustain effort over a period of time. When climbing, your forearms fail because blood isn’t getting to the muscle tissue, but it’s not because your heart isn’t pumping fast enough. Instead, the blood is having trouble reaching your forearms, which creates the pump. This means you’ll have to train your forearms, rather than general cardio abilities.

Feeling pumped means the muscles in your arms aren’t getting enough oxygen-rich blood, which helps muscles create the chemical ATP efficiently. ATP is required to release muscle fibers after they’ve been contracted, so if there isn’t enough ATP available, your muscles can’t relax. This is why you have a hard time opening and closing your hands when you’re really pumped. Once muscle fibers lock up, they squeeze the tiny blood vessels (capillaries) in your forearms shut, which means less oxygen reaches other fibers as well, and the pump grows in a vicious cycle. When zero blood is reaching your muscles, they lock up and you fall.

The goal of local endurance training is to prevent that shutdown of blood supply, providing your forearms with ATP, so fibers can relax and flex with each move.

How to Train Local Endurance

The most popular form of local endurance training for climbers is called ARC training, which stands for Aerobic, Respiration, and Capillarity. The aim of ARC training is to create more of the tiny blood vessels (capillaries) in your forearms. By climbing lots of terrain below your limit, you’ll actually develop more small blood vessels, and the existing ones will become wider. Both changes will make it harder for a pump to set in, meaning you can climb longer and recover faster.

ARC training is done by climbing easy terrain for 15 to 45 minutes at a time while maintaining a very light pump. Common methods include traversing a bouldering wall, or moving up and down routes on toprope or autobelay without coming off.

First, pick a type of terrain to cover. Vertical to slightly overhanging terrain is best because it keeps some weight on your arms, but not too much. If you can find a route or section of the wall with multiple angles in this range, that’s even better. Training on different angles will allow you to fine-tune your technique, and help break up the monotony of long sets.

Next, you’ll need to figure out how hard your target route or traverses should be. If you’ve never done ARC-style training before, start at 5.6 or 5.7 and up the grade as necessary. If you’re traversing, or don’t have a graded route to climb on, use holds that create a light pump that you can maintain for a long time. The climbing should be fairly continuous, with no hard moves that could cause a fall. It’s best if you can move without pausing to shake out frequently. The idea is to be climbing and moving, not just on the wall, for as long as possible.

For a first-timer, regardless of redpoint ability, moving continuously on the wall for 10 minutes might feel impossible, even on a vertical 5.6 or V0 boulder problem. If this happens to you, try sets of 5 minutes on, 5 minutes off, aiming for a total on-the-wall time of 30 to 45 minutes per session. Next session, try 10 minutes on, 10 minutes off, and so on. Advanced climbers may need to start just as low as beginners if they’ve never done local endurance training, but all climbers should progress quickly.


Do two to four ARC sets in each week of ARC training (up to about 4 weeks), or mix one session per week with other training. ARC training is very low intensity, so it can be done often without stressing your muscles and joints. In fact, ARC training can actually be a good way to actively recover the day after a harder workout. Next time you take extended time off from climbing, do a couple weeks of local endurance training to ease back into it. It’ll work technique and establish a good baseline in your climbing that you can build from.

Mix it Up

ARC training is one of the best ways to train local endurance, but it can be boring to stay on the wall, pulling easy move after easy move, for half an hour. Mix up your ARC routine by trying out these ideas:

  • Do technique drills. Pick a technique like drop-knees, and do as many as possible for five minutes. Pick another technique, like flagging, for the next five minutes. Work these techniques while downclimbing, too.
  • Focus on body position. Can you bring your hips in more or rotate them differently? Do you need both feet on for that move? Could you use a lower foot and cross through instead?
  • Find as many ways as possible to get from one hold to the next—which was best and why?
  • Focus on your breathing. Keep a steady breathing pattern, but mix in a harder move or two every few minutes with strong, focused exhales.
  • If you find long sets boring, even with technique drills, there are other ways to get ARC benefits through climbing with a partner, or mimicking ARC-style training outside. Any exercise that focuses on the volume and not the difficulty of climbing will help.
  • Try to climb every boulder in the gym that’s at or below a certain grade, like V1 or V0, taking short rests between problems to avoid getting pumped. Climb up and then downclimb for extra mileage, resting when needed. You won’t be gaining ARC benefits if you become too pumped, but the more continuous time you spend on the wall, the better. Or climb all the toprope routes in the gym that feel moderate and don’t pump you out. Alternate routes in your gym with a partner, only stopping to switch belays between routes.
  • If you prefer to train outside, grab a partner and climb pitches that are at least a grade below your onsight level. Try to climb two to three pitches at a time back to back, then switch with your partner. In a day at the crag, aim for at least 10 pitches. You shouldn’t feel a strong pump at any point. Drop a grade or two if you do, especially toward the end of a session. Think of it as a slightly more intense, all-day warm-up, after which you go home.
  • You can use one round of a shorter ARC session as a warm-up for any climbing or training session.

To improve your climbing by learning the proper ways to train your weaknesses, check out the rest of our series Learn to Train: A Complete Guide to Climbing Training.

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