Improve your Climbing Endurance: A Guide to ARC Training
It was fall in the Red River Gorge. For those that have never been, it is famous (and infamous) for its overhanging walls of wonderful sandstone jugs, pockets, and plates. I was working on a 10d in Miller Fork–an overhanging jug haul. Great fun with wonderful movement. All of my friends absolutely cruised it. Then me, pumped out and scared, bit it by bolt #3. I couldn’t finish the route at all. I was pumped out of my mind in a very short span of time and I felt like garbage.
Fast forward a little over year and a couple of 6 week cycles of focused endurance training later, I sidled up to Tesseract, once more. Armed with slightly bigger forearms, more confidence, and a veracious fear of failure, I SLAYED IT. I sent it with shocking ease and felt like a different climber.
There are many facets of training that go into this, but I can definitely attribute much of my improvement to focused endurance training–more specifically, ARC Training.
What is ARC Training?
ARC Training is a form of endurance training for climbers in which the focus is to increase the number of capillarization in the forearms. This thereby raises your maximum steady-state (MSS) when you are climbing. Essentially, if you raise your MSS (e.g. ” I used to be able to climb 5.10 forever, then I ARC trained, and now I can climb 5.11 forever.”), it means that you will be able to climb longer on more difficult terrain without getting pumped as quickly. See equation below:
MORE FOREARM CAPILLARIZATION = HIGHER MSS =
LESS FOREARM PUMP = MORE SENDING AND LESS FALLING
The main idea behind ARC training is that you want to maintain a slight pump for 20-45 minutes. In general you will want to stay on the wall for this amount of time. As stated by the Anderson Brothers: “This is best performed by climbing on vertical to slightly overhanging terrain that places a steady load on the forearms so that a moderate, but sustainable pump ensues for upwards of 30 minutes.” (Mark and Mike Anderson, Link here: Base Fitness )
If you would like to read more about ARC training, head on over to the Base Fitness page of the Anderson Brothers website. You can also read all about ARC training and other topics in their book, The Rock Climber’s Training Manual. The book is a holy grail of training information and I highly recommend it.
High Skill, Moderate intensity
An important thing to note is that ARCing should still involve high-skill climbing and it should simulate the outdoors as much as possible (e.g. you want to climb with good technique and ideally you are using small footholds that simulate features in outdoor climbing.)
Climbing Trainer Steve Bechtel aptly describes his criteria for effective ARC training in episode 110 of the TrainingBeta Podcast (episode 110 – listen/read here):
… I’m a huge advocate of keeping it high-skill climbing. ARCing, aerobic restoration capillary training, some people will just traverse along or climb open feet on the treadwall and we dumb down our skills there.
So, ARC all you want. But don’t spend your time climbing like garbage on a 5.6. ARCing should increase your endurance and your skills.
How to ARC.
Method 1: ARCing on a bouldering wall
This method works well if you can go to the gym when it is quiet.
What I like to do when ARCing on a boulder is half traversing and half up-climbing and down-climbing routes 1-2 grades below my limit.

I traverse to the start of a problem, usually sticking with v0-v3 routes so as not to get too pumped, then I’ll climb up and back down and then crawl over to the next problem (grade that serves the proper pump will vary from person to person)
Generally this method is nice because bouldering walls have tons of holds. With this, you can optimize your ARCing and temper the “pump” by simply decreasing/increasing the difficulty of the holds as needed.
Method 2: Autobelays
The use of autobelays is my typical method for ARC training. I try to find an auto-belay with a 5.9 and 5.10. I keep the routes generally 1-2 grades below my onsight limit (5.11). Anything slightly overhanging is ideal. I then climb up and climb down for 20-30 minutes (duration is discussed later). I usually climb something easier first, and then toss in a more difficult route at about 5 minutes. This helps me get a good pump going. By about 7 minutes, I am a little pumped and sweating lightly.
For etiquette reasons, I do my best to keep an eye out for someone waiting around to use the autobelay. Or I will typically warn people that I am about to be on the routes for 20+ minutes and let people go in front of me. It is ideal to stay on the autobelay for 10-15 minutes. You can then leave the first autobelay and go to another one. Climb something hard before departing for the next autobelay and get there quickly. The goal is to keep the pump going!
The method of swapping autobelays usually works pretty well in a crowded gym and is usually what I do after work.
Method 3: Get into a training belay-tionship
Get a buddy and have them belay you for each arc set. This might be a little time consuming since your rest periods between sets will be 20+ minutes, but this method is nice because having friends is good and the same four routes on the same two autobelays will get extremely boring after a while.
How Much and How Often?
If I am going to make a day of it, I will ARC for a total of 60-90 minutes.
I try to fit one day of ARCing each week, currently. You can also toss it into other days of climbing/training/goofing around. A sample schedule of what I am currently doing is below.
Day 1 |
Day 2 |
Day 3 |
Day 4 |
Day 5 |
Day 6 |
Day 7 |
Strength |
Bouldering ARC 20-30 min. |
Rest | ARC 3×25 min |
Rest | Climb outside |
Climb Outside |
Rest | Strength ARC 20-30 min. |
Rest | Bouldering ARC 20-30 min. |
ARC 3×25 min |
Rest |
Power Endurance |
In general, I will tack 20-30 minutes of ARC training at the end of a session, depending on if time allows. Additionally, I like to dedicate one day a week to it if I have the time, which I do right now. Note that when doing multiple sets, I rest about 10 minutes between each set.
Also please note that I do not stick to a rigid schedule in terms of days on/rest days–I rest as much as I feel is needed. I will touch on this in a later post.
General ARCing Advice
PUMP UP THE JAMS! Music is everything. Get some wireless headphones, put on your favorite spotify playlist, set a timer, and get going!*
*DIRTBAG TIP: Before I owned wireless headphones, I had earbuds with a wire and the pants I wore usually didn’t have pockets. Keeping my jams attached to me while I climb proved to be challenging. BUT I have found that a pair of earbuds combined with a Velcro arm band phone case does just the trick. I would strap the phone case to my harness and rock out!
**Other dirtbag tip: If you have the funds, pull the trigger and spend $27 on these wireless headphones– Bluetooth Earbuds – TaoTronics They work very well and for a good price, too!
STARTING OUT. Work your way up if 20 minutes is too long! If you need to break your ARC sets up into 10 minute segments for the first few sessions, it is alright. However, it is better to try to climb for the the full 20 minutes instead of shorter sets. If you need to start on 5.6/5.7 to get up to 20 minutes when you are just starting out, do it, but climb with good technique–and use small feet. If your fingers are not up to it, climb the route that has larger holds for your hands and use open feet, carefully selecting the chips on the wall as opposed to big knobs. This will be better for outdoor training. In my experience, when I was a 5.9/5.10a redpoint climber, I started out on 5.6-5.8 to be able to get myself to 20 minutes, but I did my best to use small feet if they were available.
DOWNCLIMBING. I know that when I started ARCing one of the things that I found very challenging was downclimbing, especially on autobelays. In general, if I find it too awkward to climb down a specific route, I usually use open hands and feet, trying to keep myself in a good zone aerobically.
Another note about downclimbing is that it is useful from a technique perspective (Read more about this in The Rock Climber’s Training Manual. ). Generally speaking, most of climbing is upward-centric. You look up and focus on where to put your hands. If you look down, you focus on where to put your feet–which is helpful in terms of developing your footwork. Don’t skip the downclimbing–it’s important!
TEMPERING THE PUMP. You want the pump to be manageable. At no point should you be about to pop off the wall. If you find yourself getting too pumped, rest a bit and scale back the difficulty until the pump feels manageable again. It takes a bit to figure out, but after a few sessions, you will have a feel for it. If you find that it has been 10 minutes and you are not yet sweating or feeling pumped, you can use smaller holds, try to move faster, or get on a harder route.
Feel free to shoot me an email if you have any questions at lauren@senderellastory.com.
Additionally, please note that in order to keep this site up and running, I do receive affiliate income through purchases made with links listed above. However, all the products I recommend I have used myself. I’ve had my $25 headphones for more than a year now, and they are still working brilliantly!
Here are some additional resources:
https://blog.momentumclimbing.com/what-is-arcing-an-interview-with-brendan-nicholson/
Happy ARCing!
Additionally, please note that in order to keep this site up and running, I do receive affiliate income through purchases made with links listed above. However, all the products I recommend I have used myself. I’ve had my $25 headphones for more than a year now, and they are still working brilliantly!
Try this during your next session and let me know how it goes in the comments below!
If you found this post helpful and you are ready to get stronger fingers yourself, then you are going to love my strength & fingers program: Force Over Time.
Force Over Time is a 12 week program combining strength training and hangboarding. This program can be done in addition to your climbing. That way, you can get stronger, without giving up your time to climb.