Aerobic Endurance Training on the Hangboard
The pump that won’t go away is usually an endurance problem, not a strength one. Train it with easy intermittent hangs, 10 seconds on and 5 off at 20 to 35% of your max, for 5 to 10 minutes, and keep wall climbing as the base. That protocol is my practice; the trials tested heavier loads.
You’ve just passed the crux. The rest of the route should be easy for you. Everything looks like you’re sending. But one thing isn’t right. The pump in your forearms doesn’t want to go! After a minute on the jug of the rest, you start climbing again and the tiredness kicks in instantly. At the last dynamic movement before the anchors, your fingers reach the hold and don’t close. You take the big fall and get caught by the rope.
That is probably not a strength problem. Your fingers were strong enough for those holds ten minutes earlier. It is more likely your forearms were using up more than they could resupply, and the hangboard is a good tool to work on that.
Picture from Yves Gravelle.
Why does blood flow matter for the pump?
Getting the most out of rests, climbing long easy sections, and recovering between tries all depend on how well your forearms are supplied. Climbing is intermittent by nature: you have to relax your grip to move to the next hold, and each of those brief releases is a chance for blood to get in, deliver oxygen, and carry metabolites out.
I originally wrote that how well you use those windows depends on capillary density, and that aerobic capacity decides how much strength is left on the last move. That is a reasonable physiological story, but I found no trial showing that the hangboard protocol below changes capillary density in climbers. What has been measured is related: after an 18-week bouldering programme, novice climbers improved forearm blood flow and their hangboard time (da Silva et al., 2026). Endurance does matter for climbing. In a 2025 study of 307 climbers, intermittent finger endurance was the second strongest predictor of climbing ability after finger strength (Berta et al.).
Are aerobic capacity and strength endurance the same thing?
No, and this is where most endurance training goes wrong. “Endurance” gets used for two adaptations that need different loads.
| Quality | Intensity | What it changes |
|---|---|---|
| Aerobic capacity | ~20–35% of max (my practice) | Aims at recovery and blood flow during and between efforts |
| Strength endurance | ~60–80% of max | How long you can hold a hard position before failing |
Where does the aerobic zone end? The best-measured boundary is critical force, the highest intermittent intensity you can sustain without fatigue accumulating. In climbers it averaged 41% of maximum voluntary contraction (Giles et al., 2019). Below it you can keep going; above it you drain a limited reserve. I used to cite “around 25% of maximum” as the ceiling of aerobic metabolism. I can’t source that figure, so I replaced it with critical force. My 20 to 35% band sits under 41% on purpose, to stay in the sustainable zone.
A 2022 randomised trial in Frontiers in Sports and Active Living put 54 experienced climbers through four weeks of hangboard work, twice a week, on a 12 mm hold, at 100%, 80% or 60% of maximum finger strength, plus a control group. The 100% and 80% groups improved maximal strength, the 60% group did not. The 80% and 60% groups improved stamina and endurance, the 100% group did not (Devise et al.). The intensity you pick selects the adaptation you get, and the lower intensities are not free of strength effects. I should flag that this trial’s lowest load was 60%. Nothing in it tested the 20 to 35% band I use, so that part is practice, not proof.
How do you train endurance on the wall?
Traditionally, climbers train endurance on the wall with long sessions or specific exercises. Three that work for me: climb four routes without rest, four times over; do ten boulders back to back; climb circuits on a training wall. For each one, aim for an intensity as continuous as possible. The goal is to link as many movements as you can, well below your limit, without having to stop.
Wall work is the most specific way to do this, and it should stay the bulk of your endurance training.
How do you train endurance on the hangboard?
The hangboard adds three things the wall does not: it is fast, the intensity is controllable, and it is almost purely physical, so a bad day of climbing movement doesn’t ruin the stimulus.
For the aerobic end, hang intermittently at 20 to 35% of your maximum, 10 seconds on and 5 seconds off, for 5 to 10 minutes per set. It should feel easy for the first two minutes. If you are gripping hard, the load is too high. Stop if a finger hurts.
To find that load:
- With a force plate, pull as hard as you can for 5 seconds to get your max, then take 20 to 35% of that number and hold it. Watching the number is the point: the target is a narrow band, and it is very easy to drift above it as you fatigue.
- Without one, use the minute test. Pick a load you can hold continuously for a full minute with effort left over. That is a rough guide to the right band, not a validated test. Keep your feet on the ground and take weight off the holds until you find it.
Partial hangs, with your feet still on the floor, make this easier to dial in than full hangs with added or removed weight. You can adjust mid-set instead of stopping.
For heavier intermittent work, see Repeaters. To estimate where your own critical force sits, see The critical force test.
When should you train endurance?
Endurance work will make you tired. Don’t put it before a climbing session or a strength session: you will just do both worse.
A block of it is useful to prepare for a strength cycle, before a climbing trip, or before an event. It also works without a dedicated focus, one day a week, kept easy. Because the intensity is so low, I find it recovers fast and stacks well with everything else. That recovery claim is my experience.
Where to go next
- Endurance and the pump: the whole library on training the forearms not to fade.
- How to train finger endurance: critical force, repeaters and climbing below threshold.
- Repeaters: the heavier, strength-endurance side.
- Warm-up routine: do it before any hangboard work.
Do this in Entralpi
The max strength test measures your max; type it in Settings (Profile, then Settings, under Physical Profile, Max strength), and a load in % max becomes kilograms. The endurance test gives your critical force and a sustainable force, which endurance, recovery and rehab workouts use. Then start a workout from the Train tab or build your own with 10 seconds on and 5 off. Without the plate, the timer runs the intervals and you use the minute test for the load.
Sources
- Devise M, Lechaptois C, Berton E, Vigouroux L (2022). Effects of different hangboard training intensities on finger grip strength, stamina, and endurance. Frontiers in Sports and Active Living.
- Giles D, et al. (2019). The determination of finger-flexor critical force in rock climbers. International Journal of Sports Physiology and Performance.
- Berta P, et al. (2025). Validity and normative scores of finger flexor strength and endurance tests estimated from a large sample of female and male climbers. Journal of Sports Sciences, 43(3).
- da Silva JMR, et al. (2026). Forearm blood flow and vascular conductance improve after 18 weeks of bouldering training in novice climbers. Frontiers in Sports and Active Living.
