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Climbing Critical Force Calculator 2020

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New! - Sport Climbing Level Calculator!

If you're a sport/lead climber, there's a new tool available! The Sport Climbing Level Calculator!

The Sport Climbing Level Calculator is designed specifically for sport/lead climbers. It analyzes the athlete's finger strength and forearm endurance profile to estimate the expected climbing grade accurately.

The Sport Climbing Level Calculator will:

  • Let you know how hard you could be climbing at your current fitness level
  • Pinpoint your biggest weaknesses and help you effectively target them
  • Give you an instant automatic assessment and help you design a training plan tailored to your exact needs!

If you're a sport/lead/trad climber, and you're looking for an automatic in-depth climbing performance assessment, follow this link.

Critical Force Calculator

The Critical Force Calculator will help you determine where you stand with your forearm aerobic endurance. If you’re a strong sport’s or trad climber, but end up pumped on your way to the crux, it means that your forearm aerobic endurance likely requires some attention. The Critical Force Calculator will also allow you to find the optimum load at which you should train so that you will soon breeze up through those endurance routes! 

The calculator provides a basic assessment of your climbing endurance level. If you would like to get a detailed personal climbing performance evaluation like this one, just send your input numbers to me directly at [email protected], and I’ll get back to you with an in-depth lead climbing level evaluation. I will analyze your current performance and give you hints on what to train to quickly improve your climbing!

For best results, train exactly at CF intensity and try to maximize the total work done.

Instructions

To determine your forearm aerobic endurance Critical Force, you can use the calculator below. Input your body weight and your 7-second MVC on a 10 – 35 mm edge, followed by respective times to failure for the 7/3 Endurance Repeaters at 80% MVC-7 and 60% MVC-7. For the last measurement you may choose 45%, 50% or 55% MVC-7 load, just make sure that you fail in under 1200 seconds. 

The calculator will output your CF and the weight you need to subtract in order to exercise exactly at CF load. You will also receive a brief assessment of your strength and forearm aerobic endurance. The calculator is calibrated for the half crimp grip on a 20 mm edge, to enable a direct comparison with the results published in [1]. The bouldering level prediction is based on the results of the survey published at [2].

You can find more detailed information regarding the role of the Critical Force in sport’s and climbing endurance training in [3].

Example Critical Force test

Let’s say you weigh 68 kg, and you take the MVC-7 test on a 20 mm edge. You can add 32 kg to the bodyweight and hang for 7 seconds, so the MVC-7 load is 100 kg. Now we can calculate your 80%, 60% and 45% loads, which are 80 kg, 60 kg and 45 kg respectively.

  1. Test your T80% :
    • To set the 80% load, you must add 12 kg to the harness.
    • Execute a set of 7/3 Repeaters until failure.
    • Add the hanging times together. This means that if you were able to execute 10 full hangs and failed at hang 11 in the 4-th second, then your T80% is 74 seconds.
    • Rest 15 minutes before the next test.
  2. Test your T60%
    • To set the 60% load, you must remove 8 kg using a pulley system.
    • Execute a set of 7/3 Repeaters until failure.
    • Add the hanging times together. This means that if you were able to execute 15 full hangs and failed at hang 16 in the 4-th second, then your T60% is 109 seconds.
    • Rest 30 minutes before the next test.
  3. Test your T45%:
    • To set the 45% load, you must remove 23 kg using a pulley system.
    • Execute a set of 7/3 Repeaters until failure.
    • Add the hanging times together. This means that if you were able to execute 60 full hangs and failed at hang 61 in the 4-th second, then your T45% is 424 seconds.
    • If your aerobic endurance is very good, and you are able to last more than 20 minutes at the 45% load, you should change the load to 50% or even 55% of your MVC-7 and redo the test.
  4. Enter your data into the form and press calculate.
Input
kg lbs
T(45%) [s]
T(50%) [s]
T(55%) [s]

Results

The calculator lets you compare your finger strength and endurance with data from hundreds of other climbers, which I collected over more than four years of doing climbing research and running the site. It outputs the climbing grade you should be able to send with your current results and gives you precise suggestions regarding what aspects of your climbing you should focus on to move forward.

Register and get 1-month access to the full version of the calculator, together with all Premium Content on Strengthclimbing.com. In the sections below, you'll find detailed instructions on using the tool to leverage its full potential and to get an accurate automatic assessment.

Unregistered users can try out the demo version of the calculator to get a glimpse of its capabilities. In addition, I've prepared a set of trial values that you can input to see how it works!

Demo version test

To test the Demo Version of the Sport Climbing Level Calculator, please input the demo dataset:

  • Body Weight: 65 kg or 144.4 lbs
  • Test edge: 20 mm
  • MVC-7: 105 kg or 233.3 lbs
  • T80: 77 s
  • T60: 136 s
  • T45: 323 s

Identify your climbing weaknesses

I often ask other climbers why they love climbing and usually get similar answers. It's about hanging around with buddies, being in nature, and living an adventure. But it's also about focusing on a challenge, the act of self-improvement, and being able to surpass their weaknesses. Yes, climbing is a great sport, and we spend much of our time trying to get better at it to impress our friends and even ourselves by achieving what we thought was impossible.

And yet, one of the most frustrating things about climbing is when we hit a plateau. After a few years of training, most of us have been there. You climb a lot, have a fixed training routine that works, progress continuously, and suddenly boom - your progress stalls.

That's a clear sign that you need to change how you train. Maybe you were focusing too much on finger strength training or completely neglected it and relied solely on aerobic endurance. On the other hand, it's also possible that your anaerobic endurance is poor, and you get pumped quickly after a few hard moves. You may lack technique and tactics because you need to climb outdoors more. Or, contrary to that, you might be overtraining by combining long weekends at the crag with hard weekly training at the gym during the summer.

Getting a clear perspective can be challenging when trying to find your own weaknesses, so the best solution is to find a coach, get him to take a closer look at your climbing, and ask for a training program tailored to your goals. The second best option is to run a series of tests and send them to an experienced climbing analyst for a remote assessment. However, both these options can be costly and time-consuming.

That's why I created the Sport Climbing Performance Analyzer tool, which can quickly pinpoint what's holding you back and see what improvements you can expect if you address the issue. Of course, nothing can replace a good climbing coach, but the tool will quickly show you how to eradicate your most significant climbing deficits and get back on track with your progress.

Sport Climbing Level Calculator instructions

In the paragraphs below, you will find detailed instructions on how to perform the measurements safely and accurately. But, again, remember that thorough preparation is essential.

Equipment required for performing the measurements

To perform the Sport Climbing Level Calculatoe measurements, you'll need the following:

  • A hangboard with a wooden 10 - 35 mm edge
  • Some additional load
  • A pulley setup for reducing your body weight
  • Bathroom scales or a crane scale
  • A means to measure test time

As far as the hangboard is concerned, if you're going for the standard 20 mm test, you have the following options:

For weaker climbers, performing the test with a 30 mm edge or a 33 mm edge (BM2K default) might be better. That will also enable smaller load reductions when designing the Endurance Repeaters exercise protocol [5]. Of course, you must ensure that you use the same edge for the MVC-7 measurements and the following endurance measurements.

Be well rested

To correctly test your finger strength and endurance with the Sport Climbing Level Calculator, ensure that you are well rested from your previous climbing activities. That typically means resting for 24 - 72 after your last training session, depending on its intensity.

Warm up and recruit

Before engaging in any climbing activities, you should warm up thoroughly. Pay special attention to your back, shoulders, forearms, and fingers. Then, top up your warm-up with a series of 3 - 5 progressively heavier 7 - 10 second hangs. For detailed information on warming up for climbers, you may look at my article, this video from Dr. Tyler Nelson, or this video on how to warm up your fingers specifically [6][7][8].

Determine your weight

To perform an accurate measurement, you should prepare a bathroom scale, a hook scale, or a dedicated tool, such as the Tindeq Progressor [9]. It is recommended to weigh yourself in full gear with the added load before each test hang. However, it is also helpful to know your body's weight to relate it to the total hang load.

Select the tested hold position

The Sport Climbing Level Calculator is designed for tests on flat wooden edges in the half-crimp or open-hand position - you may choose the stronger hold position. The tests can be performed on any edge depth between 10 - 35 mm. Typically the tests are performed on 20 mm edges, but weaker climbers will find deeper edges more useful.

Test your MVC-7

The MVC-7 test is the first test you must run to assess your finger strength and get the point of reference for your other tests. If this is your first time doing this, please refer to this article to familiarize yourself with maximum finger strength testing and weighted hangs [10]. Here you'll find tons of helpful information on how to run the test safely and accurately.

Let's say you weigh 68 kg, and you take the MVC-7 test on a 20 mm edge. You can add 32 kg to the body weight and hang for 7 seconds, so the MVC-7 load is 100 kg. Now we can calculate your 80%, 60% and 45% loads, which are 80 kg, 60 kg and 45 kg respectively.

Test your T80%

The 80% MVC-7 test is like doing a Heavy Repeaters until failure. It lets you check the efficiency of your anaerobic alactic/lactic system, which is critical for sending routes with hard bouldery cruxes. To set the 80% load, you must add 12 kg to the harness. Execute a set of 7/3 Repeaters until failure. Add the hanging times together. This means that if you were able to execute 10 full hangs and failed at hang 11 in the 4-th second, then your T80% is 74 seconds. Rest 15 minutes before the next test.

Test your T60%

The 60% MVC-7 test specifically targets your anaerobic lactic system, which is heavily taxed when climbing through sustained sequences of moderately hard moves. To set the 60% load, you must remove 8 kg using a pulley system. Execute a set of 7/3 Repeaters until failure. Add the hanging times together. This means that if you were able to execute 15 full hangs and failed at hang 16 in the 4-th second, then your T60% is 109 seconds. Rest 30 minutes before the next test.

Test your T45/50/55%

The 45/50/55% MVC-7 test lets you verify how well your aerobic endurance system works. To set the 45% load, you must remove 23 kg using a pulley system. Execute a set of 7/3 Repeaters until failure. Add the hanging times together. This means that if you were able to execute 60 full hangs and failed at hang 61 in the 4-th second, then your T45% is 424 seconds.

If your aerobic endurance is very good, and you are able to last more than 10 minutes at the 45% load, you should change the load to 50% or even 55% of your MVC-7 and redo the test. Enter your data into the form and press calculate.

The idea of Critical Force

Critical Speed (CS) and Critical Power (CP) are well-known concepts used in sports training. Imagine yourself walking at about 6 km/h – you could probably carry on like this for hours. On the other hand, unless you’re an elite marathon runner, you probably couldn’t run at 20 km/h for very long. This means that your running critical speed, which is the speed at which you could theoretically run for an unlimited time, lies somewhere between 6 – 20 km/h. Cycling coaches use the term Critical Power, which defines the power output, at which you could cycle for hours. For climbing, the term Critical Force (CF) is more relevant, meaning the maximum load at which you should be able to climb indefinitely without falling off.

The Critical Force determines the performance on endurance routes, and it is directly related to the forearm aerobic capacity. Critical Force is usually expressed as a percentage of the climber’s body weight, or their maximum voluntary contraction (MVC). For elite sport climbers, it could reach up to 60% of their MVC, while for boulderers and poorly conditioned route climbers, it could be below 30% MVC. Knowing your CF is important because it was shown that aerobic capacity is trained most efficiently exactly at critical loads [11].

References

  1. Giles, D., Chidley, J.B., Taylor, N., Torr, O., Hadley, J., Randall, T., Fryer, S., 2019. The Determination of Finger-Flexor Critical Force in Rock Climbers. International Journal of Sports Physiology and Performance 1–8. (link)
  2. https://toclimb8a.shinyapps.io/maxtograde/ (link)
  3. J. Banaszczyk, StrengthClimbing – Endurance Repeaters, May 2, 2019. (link)
  4. r/climbharder, Beastmaker 1000 and 2000 edge/hold sizes, Jul. 18, 2019. (link)
  5. J. Banaszczyk, StrengthClimbing – Endurance Repeaters – Forearm Aerobic Endurance Hangboard Routine, May 2, 2019.(link)
  6. J. Banaszczyk, StrengthClimbing - 9 Powerful Reasons To Warm-Up For Rock Climbers (Review), Dec. 4, 2020. (link)
  7. Dr. T. Nelson, C4HP, Connective tissue warm-up drill, Jan. 31, 2020. (link)
  8. A. MacFarlane, Finger Warm Up for Climbers, Oct. 4, 2020. (link)
  9. tindeq.com (link)
  10. J. Banaszczyk, StrengthClimbing – Finger Strength Measurements For Rock Climbers Made Easy!, Feb. 17, 2023.(link)
  11. McGawley, K., 2010. The application of the critical power construct to endurance exercise. University of Brighton. Student thesis: Doctoral Thesis. (link)
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2 thoughts on “Climbing Critical Force Calculator 2020”

  1. How long should we wait between performing the MVC-7 test and the 80%, 60%, 50% tests? How long should we wait in between percentage tests?

    1. I recommend splitting the tests into two training sessions. In the first session, you determine your MVC-7, then wait 10 minutes and run the 80% test. Wait 15 – 20 minutes and run the 60% test. You then leave the last test for a separate session.

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