Endurance Training

Blood Flow Restriction (BFR) Training for Rock Climbing - Introduction

Blood Flow Restriction is one of the most recent innovations in climbing training. I first encountered this finger strength training method in the 2021 Nugget Climbing interview with Tyler Nelson [nugget]. I tried it, and I was amazed with the results. After one training cycle of about 6 - 8 weeks, my 7-second finger strength (MVC-7) measured on a 20 mm edge hit an all-time peak of 124 kg! Moreover, I could repeat this result in 2022 with another BFR cycle.

At that point, I started focusing more on endurance training, and my finger strength declined to 109.5 kg in August 2023. But now, I did another quick BFR cycle to see if I could quickly boost my finger strength. Read on if you're curious to find out what the results were!

Sport climbing level calculator for Tindeq Progressor

Below you'll find a simple calculator that makes estimating your current redpoint level possible based on the Peak Load and Critical Force measurements done with the Tindeq Progressor. The calculator also lets you compare the result obtained with the model developed by Lattice Training and the model I’ve created for this post. Still, at this early development stage, I believe the calculations based on the earlier 4-trial method are more reliable, although the tests are more time-consuming. To get a detailed automatic sport climbing performance analysis based on the 4-trial method, please try my Sport Climbing Level Calculator.


Dr. Tyler Nelson's Density Hangs - Introduction

Ever since rock climbing began to be perceived as a sport, people started looking for ways to get better at it. Although what combination of skills makes someone a great climber remains a mystery, undoubtedly strong fingers are one of the essential qualities you need to send hard grades.

It wasn't long before climbers realized that hanging off the tips of your fingers on small edges is a simple and effective way to improve finger strength. Thus, fingerboards were born. Since then, many different ways have been invented to develop specific finger and forearm muscle qualities, such as hypertrophy, recruitment, and endurance. However, the first finger training method was hanging on a narrow edge for as long as possible.

Shortly thereafter, climbers began adding more variety to this rudimentary training method. Repeaters, MaxHangs appeared and hanging until failure began to be seen as potentially dangerous to the shoulders [1][2]. Only recent scientific discoveries in the structure and function of muscles and tendons allowed us to appreciate the benefits of long-duration isometric dead hangs. So let's dive in and see how going back to the roots of fingerboard training could help you revamp your climbing and potentially get you rid of nagging injuries such as tendinosis.

Dr. Tyler Nelson - at the cutting edge of rock climbing science

Before we move on, let me introduce the person who has rekindled the interest in long-duration isometric hangs for rock climbing training several years ago. Dr. Tyler Nelson is a certified NSCA Strength and Conditioning Specialist and the co-founder and a content creator for The Performance Climbing Coach seminar series, The Camp 4 Human Performance Climbing Assessment, and The Bstrong BFR Certification Course. He is a passionate climber and does invaluable research on methods to enhance climbing performance, the results of which he often shares through his Instagram and his YouTube channel [3][4][5].

Dr. Nelson developed a number of effective finger strength training protocols based on solid scientific evidence. His routines are safe and easy to implement, as he prefers to use autoregulatory protocols rather than hanging off your fingertips with dozens of kilograms attached to the harness. His Recruitment Pulls and Velocity Pulls are exciting techniques that deliver stimuli distinct from traditional hangboarding and often help climbers overcome performance plateaus [6].

Moreover, he effectively popularizes blood flow restriction (BFR) training among the climbing community. His system allows achieving strength gains at low loads while managing finger, elbow, and shoulder injuries [7]. However, I believe that his best-known protocol and one that first made him famous are the so-called Density Hangs, which are the subject of this post.

What are Density Hangs?

Density Hangs are a medium-intensity hangboard routine where you hang off an edge for 20 - 40 seconds. The exercise promotes hypertrophy of the forearm muscles and the muscle-tendon junctions, hence its name. Density Hangs additionally trigger advantageous remodeling of the tendons, making them more robust and reducing injury risk.

Interestingly enough, Density Hangs are very similar to the less known SubHangs, developed independently and in parallel by Dr. Eva López [8]. The main difference between the two methods is the underlying philosophy. SubHangs, as discussed in one of my previous articles, were designed as an endurance training protocol, aiming to improve the phosphocreatine (PCr) recovery and the total PCr levels in the forearm muscles. In addition, some muscle hypertrophy was also expected due to anabolic hormone secretion, caused by lowered blood pH and fast-twitch muscle recruitment.

Dr. Nelson's structure-oriented approach aims at building thicker and denser tissues and promoting tendon health through a specific sliding effect occurring in the tendons during long-duration isometrics. In this way, a solid muscle-tendon system is formed, allowing for handling higher training loads and increasing finger strength safely and effectively.

Density Hangs protocol details

  1. Choose 2 - 3 hold positions for training. Consider:
    • Slopers
    • Half crimp
    • Open hand
    • Full-crimp
    • Pinch (you may use pinch blocks)
  2. For each position, choose a hold on which you can hang with two arms between 20 and 45 seconds, ideally without added load.
  3. Perform a set of Density Hangs:
    • Hang for 20 - 40 seconds.
    • Rest for 10 - 20 seconds - use 2:1 hang to rest ratio.
    • Perform 2 - 3 reps - until you fail.
    • If you can do more than 3 reps, you can add 1 – 2 more, or increase the duration of the last rep until you fail.
  4. Rest 3 - 5 minutes
  5. Repeat the set for the same hold position or move to the next position.
  6. For each hold position, perform 2 - 3 sets. That amounts to 4 - 9 sets per training session.
    • According to Dr. Nelson, doing 8 sets is often the ideal training volume.

Table 1: Density Hangs protocol summary.

Density Hangs
Hang test time [s]20 - 45
MVC-7 load55 - 85%
Sets4 - 9
Hangs/set2 - 3
Hang time [s]20 - 40
Rest betw. sets [min]3 - 5
TUT [s]80 - 900
Total time [min]10 - 100

Density Hangs protocol remarks

  1. Focus on slow static loading until muscular failure
  2. Density hangs are ideally performed without added load, at around 75% of maximum strength (MVC-7)
    • To calculate your Density Hangs loads and training edge sizes, you may use my Hangboard Training Calculator [9].
    • Strong athletes should consider doing multiple reps until failure (Repeater style) instead of adding load - 2:1 hang to rest ratio

Quick summary

Eric Hörst Hangboard Moving Hangs climbing training protocol

The Hangboard Moving Hangs (HMH) climbing training protocol was described by Eric Hörst in his book Conditioning for Climbers [1][2]. Because the intensity of the exercise is rather low, even beginner climbers with a couple of months of training under their belt can give it a try. The great thing about the protocol is that it makes it possible to easily control the difficulty by changing the hold size, the placement of the feet support, or the pace at which the hands are moved around the hangboard. This facility in load control makes it possible to train either anaerobic endurance or aerobic endurance, depending on how the intensity is related to the climber’s Critical Force (CF).

The Hangboard Moving Hangs climbing training protocol is a perfect introduction to hangboarding, because it’s safe, it puts less strain on the shoulders than typical dead hangs, and it’s easy to do. I started hangboarding with the Hangboard Moving Hangs climbing endurance protocol myself, and I would recommend it to beginners.

Simple and safe method of training both aerobic and anaerobic endurance. Suitable even for beginners!

Eric Hörst Hangboard Moving Hangs climbing training protocol details

  1. Mount the hangboard, and support your feet on a chair, or some screw-ons on the wall.
  2. Start moving your hands around the hangboard, changing the hold every 3 – 5 seconds.
  3. After a while, you will start to develop a pump in your forearms. If so, try to shake out on some jugs.
  4. Continue moving around the hangboard for a total time of 5 – 10 minutes.
  5. Dismount the hangboard, rest for about 10 – 20 minutes, depending on set duration.
  6. Perform 2 – 3 sets.

Eric Hörst Hangboard Moving Hangs climbing training routine remarks

  • You can increase the intensity by moving the chair further behind the hangboard.
  • If you want to train aerobic endurance instead of strength endurance:
    • Choose bigger holds to avoid getting pumped, and increase the number of sets,
    • Reduce the inclination – move the feet support closer to the hangboard.
  • Once you improve, try to reduce the size of the holds on which you shake out.

Table 1: Eric Hörst Hangboard Moving Hangs climbing training protocol summary.

Hangboard Moving Hangs
MVC-7 load (unilateral)15 - 95%
Sets2 - 3
Positions3 - 10
Hang time [s]3 - 5
Set duration [min]5 - 10
Rest betw. sets [min]10 - 20
TUT/arm [s]375 - 750
Total time [min]30 - 90

Hangboard Moving Hangs anaerobic endurance training demo session video

In the video, you can watch an example demo session of the Hangboard Moving Hangs protocol. I set the difficulty to reach exhaustion around the 5-minute mark. This means that I operate mostly in the anaerobic regime and train strength endurance.

Maximum Voluntary Contraction and Critical Force

You can use the hangboard to develop both aerobic and anaerobic endurance, but how to tell which one you are training? For any intermittent hangs protocol, such as the Hangboard Moving Hangs, we can define what is called the Critical Force (CF). To make things very simple, we can say that the Critical Force is the load at which equilibrium is struck between the energy used by the muscles during the work period and the energy replenished by the blood flow during the rest period. The ratio of the work period to the rest period is called the duty cycle [3]. In theory, at Critical Force load, the exercise can be carried out indefinitely. In practice, this is not the case, but 20 minutes should be easily manageable.

To train aerobic endurance, the hang load on either hand should not exceed the climber’s CF. Interestingly enough, it was found that the best results are achieved when the hang load is exactly CF [4]. To train anaerobic endurance, the loads must exceed CF, which usually is the case, e.g. Hangboard Repeaters [5]. The concept of CF is closely related to the original idea of Critical Power, which is more appropriate to sports such as cycling. You can find more information on Critical Power in [4][6][3]. More detailed information on Critical Force in climbing can be found in [7][8]. You can also easily calculate your CF with the Critical Force Calculator tool [9].

Aerobic endurance is most efficiently trained exactly at Critical Force load.

Critical Force can be expressed in newtons, but it is usually more convenient to relate it to the Maximum Voluntary Contraction (MVC). The MVC is the maximum load with which the climber can hang for a given time on a given hold. The measurement time usually lies between 5 seconds (MVC-5) to 10 seconds (MVC-10). In this blog, the 7-second MVC (MVC-7) is typically assumed, which is consistent with [10]

The MVC is usually determined for two arm (bilateral) hangs. In the case of the HMH protocol, one arm is mostly used (unilateral). For simplicity, we will assume that the MVC for one arm hangs is precisely 50% of the two

Quick summary

Eva López SubHangs strength endurance protocol

Eva López SubHangs strength endurance protocol was introduced on her blog in early 2018 [1]. The method is very similar to her MaxHangs routine for finger strength. Still, longer hang times are applied, which is aimed primarily at improving strength endurance and potentially also strength itself, through hypertrophy. For the MaxHangs, hang times of about 10 seconds are common, but for the SubHangs strength endurance protocol, hang times of up to 45 seconds are used [1][2].

In a way, Eva López SubHangs strength endurance protocol is quite similar to the more old fashioned way of hangboard training, where long hangs till failure were preferred [3]. This resulted in many shoulder injuries because the shoulder joint gets fatigued quicker than the fingers [4]. The protocol can be executed in two versions, the minimum edge with no added weight (SubHangs MED) and with added weight (SubHangs MAW). However, the MAW version is recommended only for advanced climbers [1].

Eva López SubHangs MED protocol details

  1. Choose an edge on which you can hang between 20 and 45 seconds.
  2. Perform one hang of 20 – 45 seconds, rest for 30 seconds up to 2 minutes.
  3. Perform 4 – 8 sets.

Eva López SubHangs MAW protocol details

  1. Choose an edge between 14 – 20 mm and a corresponding load, so that you can hang between 20 and 45 seconds.
  2. Perform one hang of 20 – 45 seconds, rest for 30 seconds up to 2 minutes.
  3. Perform 4 – 8 sets.

Table 1: Eva López SubHangs protocol summary.

SubHangs MED/MAW
Hang test time [s]20 - 45
MVC-7 load55 - 85%
Sets4 - 8
Hang time [s]20 - 45
Rest betw. sets [s]30 - 180
TUT [s]80 - 360
Total time [min]3 - 27

SubHangs strength endurance routine remarks

  • The SubHangs strength endurance MAW protocol is only recommended for advanced climbers with a lot of training experience. Beginners and intermediate should stick to SubHangs MED.
  • You can tailor the program to suit your current performance requirements:
    • If you need to improve your recovery time between sustained sections of a route, you should start with long rests of 2 – 3 minutes between sets. Shorten the rests gradually while progressing through the program, down to a minimum of 30 seconds. Keep the hang duration or load constant.
    • Alternatively, if you need to be able to hold a specific grip position for a longer time, you can increase the hang period and keep the pause unchanged.
  • If the pause between sets is less than 2 minutes, select the load in such a way, so that you reach failure or near-failure in the last hang of the session.
  • If the pause between sets is 2 – 3 minutes, select the load in such a way so that you reach failure or near-failure at the end of each set.
  • You may need to adjust the load (SubHangs MAW) or edge depth (SubHangs MED) for each set or even repetition, to reach failure exactly when it is required.
  • Training frequency [5]
    • For improving your strength endurance perform the drills twice a week, with  48 – 72 hours recovery between the sessions.
    • If you want to maintain your current strength endurance level, exercising once a week should be sufficient.
    • For advanced climbers who train 5-6 times per week, three SubHangs sessions a week are possible if they don’t climb during the weekends.
  • Make sure to warm up your shoulders before you start the protocol. The longer hangs, above 30 seconds, can be very straining on the shoulders and potentially lead to rotator cuff injuries.

Video 1: Short video demonstration of the Eva López SubHangs protocol.

Make sure to warm up your shoulders thoroughly, if you're going for the long hang times above 30 seconds.

Typical SubHangs strength endurance training cycles

The basic principle for the SubHangs protocols is to create a training overload by progressing the volume. Steve Bechtel applied a similar approach in his 3-6-9 Ladders strength training protocol [6][7]. Once the progress slows down, you should start changing other workout parameters. You may try the following two approaches [5]:
  • Keep the hang intensity and recovery times fixed while extending the hang duration up to 45 seconds.
  • Keep the hang intensity and hang times fixed while shortening the recovery time between sets down to 30 seconds.

SubHangs strength endurance training cycle for beginners

  • Week 1: 2 sets/session
  • Week 2: 3 sets/session
  • Weeks 3 and 4: 4 sets/session
  • Weeks 5 and 6: rest
  • Weeks 7 and 8: 3 sets/session
  • Weeks 9 and 10: 4 sets/session
For beginners, a single 4-week cycle may be sufficient.

SubHangs strength endurance training cycle for intermediate

  • Week 1: 3 sets/session
  • Weeks 2 and 3: 4 sets/session
  • Week 4: 5 sets/session
  • Week 5: rest
  • Weeks 6: 3 sets/session
  • Week 7: 4 sets/session
  • Weeks 8 and 9: 5 sets/session

SubHangs strength endurance training cycle for advanced

  • Week 1: 3 sets/session
  • Week 2: 4 sets/session

Quick summary

Zlagboard Forearm Endurance Workout

The Zlagboard comes with a built-in protocol for forearm endurance training, developed by Duncan Brown, an Australian climber and coach [1][2]. The idea behind the Zlagboard Forearm Endurance Workout is to generate a severe forearm pump, targeting the anaerobic lactic energy system. This allows you to train both physiological tolerance and psychological tolerance to high acidic loads [3]. The Zlagboard Forearm Endurance Workout could perhaps be viewed as a rather extreme version of Hangboard Repeaters, or Eva Lopez SubHangs protocol, where the hang time and the rest times are one minute each [4][5].

Zlagboard Forearm Endurance Workout details

  1. Mount the hangboard and support your feet on a chair, or some screw-ons on the wall.
  2. Choose a pair of holds, e.g., 20 mm edges, and hold it for 1 minute.
  3. Dismount the hangboard and shakeout for 1 minute.
  4. Perform ten sets.

Table 1: Zlagboard Forearm Endurance Workout summary.

Zlagboard Endurance
Approx. BM load30 - 70%
Hang time [s]60
Rest betw. sets [s]60
TUT [s]600
Total time [min]19

Zlagboard Forearm Endurance Workout remarks

  • To prevent blood from flooding your forearms directly after dismounting the hangboard, hold them up for a couple of seconds, and shake out.
  • You may apply the above strategy after finishing a pumpy route – holding your hands up will help you regenerate faster before your next burn.
  • You can increase the level of intensity of the exercise by squeezing and releasing your fists in the upright position throughout the 1 minute of rest.

Muscle endurance and fatigue mechanisms

Muscular endurance in itself is a complex subject, and forearm endurance in climbing is no exception. In general, endurance can be defined as the ability to maintain or to repeat a given force or power output, which perfectly describes the periods of intermittent contractions mixed with periods of sustained contractions of the finger flexors, characteristic for climbing on a sport route [6][7][8]. Currently, the physiological mechanisms that allow elite level climbers to maintain repeated intense isometric contractions for prolonged periods of time are not fully understood, but there is evidence that flexor muscle oxidative capacity, capillarity, and ability to profuse O2 may be the governing factors. For one thing, it was discovered that high-level climbers are able to de-oxygenate the flexor muscles to a greater extent than intermediate climbers and non-climbers during sustained contractions. What is more, the flexor digitorum profundus (FDP) oxygenation recovery is significantly quicker in elite climbers during both sustained and intermittent contractions, while it is known that enhanced O2 delivery to the exercising muscles directly attenuates muscle fatigue and increases muscle efficiency [9][10][11]

Since blood flow brings oxygen necessary for aerobic adenosine triphosphate (ATP) production and removes by-products of metabolic processes in working muscles, it plays an important role in the maintenance of force output.  As the muscles contract, the mean arterial blood pressure increases, leading to a decrease in the net blood flow to the working muscle and inducing fatigue. Surprisingly, blood flow occlusion does not seem to be the critical factor in the development of fatigue, as the decrease in the MVC force was found to precede significant changes in the blood flow to the muscle [10][12].

ATP is the energy source fuelling muscle contractions, and glycogen oxidation is the primary source for ATP regeneration during high-intensity intermittent exercise [13]. Glycolysis leads to blood lactate (Lac) and hydrogen ions (H+) accumulation, which until recently was thought to play a vital role in the development of muscle fatigue. This view is now being challenged, as several recent studies have shown that decreased pH may have little effect on contraction and MVC of human muscle [10][14].

Anaerobic metabolism in skeletal muscle also involves hydrolysis of phosphocreatine (PCr) to creatine and inorganic phosphate (Pi). The concentration of Pi increases rapidly during intense contractions, which appears to be the most important cause of fatigue. It is hypothesized that elevated levels Pi can lead to decreased force production by limiting Ca2 release from the sarcoplasm (SR) [14][15]. Finally, mitochondrial respiration produces ATP and consumes O2 in a process that generates reactive oxygen species (ROS) that are known to contribute to muscular fatigue [10].

Zlagboard Forearm Endurance Workout hang intensity determination

So what does happen when the Forearm Endurance Workout is being executed? Let’s first take a look at the hang intensity. Based on a simple analysis of the mechanical system involved and some very rough measurements, we can state that the hang load lies in the range between 30% – 70% of the climber’s body mass (BM), depending on the type and position of the feet support used [16]. This result can be confirmed through a simple experiment, as it is shown in Figure 1. In terms of the %MVC, this could mean anything, but if we choose a reasonably comfortable hold, on which the training climber’s MVC is around 150% BM, then the hang intensity should lie somewhere in the range

Quick summary

Endurance Repeaters – Forearm Aerobic Endurance Hangboard Routine

The Endurance Repeaters Aerobic Endurance Hangboard Routine is a less known modification of the standard 7/3 Hangboard Repeaters strength endurance protocol. Endurance Hangboard Repeaters were discussed by Tom Randall and Ollie Tor in the TBP 114. The idea behind this method is to perform intermittent hangs until failure, with the load reduced to only 30 – 40% of your maximum voluntary contraction (MVC). This makes it a very low-intensity aerobic exercise, which will allow you to build up very slowly towards forearm pump, which is much more similar to what happens on a long endurance route [1]

In endurance sports such as long-distance cycling, running or swimming, endurance is traditionally trained through continuous high-volume (e.g., 60 – 90 minutes) training sessions at relatively low intensity, around 60 – 65% of VO2max [2]. This kind of training is known to introduce adaptations, which include improved capillary density and vascular conductance, increases in size and density of the mitochondria, aerobic enzymes and fat oxidation, as well as sparing of muscle glycogen, reduced rates of lactate (La-) production and enhanced La- removal, ultimately resulting in improved O2 supply and thus maximal endurance capacity [3][4][5][6]. Endurance Repeaters are an attempt to apply the traditional endurance training principles to climbing.

Critical Power and the energy store component in aerobic endurance

To better understand the principles behind modern endurance training theory, we need to explain the concept of Critical Power (CP). CP was introduced to reflect the highest exercise intensity that is solely dependent on a renewable aerobic energy supply. Simply speaking, CP is the maximum power that a muscle can keep up for a very long time without fatigue [7]. You may think of CP as the “maximal aerobic power”, though this particular term (MAP) is used in literature to describe the power output associated with VO2max [8]. Since in hangboard training, we deal with dead hangs, which involve isometric muscle action, we will use an analogous term of Critical Force (CF) instead of CP. The higher your CF is, the harder you can climb while relying on the aerobic energy system. CF can be given in newtons, but it usually makes more sense to express it as a percent of the climber’s maximum voluntary contraction (MVC).

The second important parameter is the so-called energy store component W’, which indicates the maximum amount of work that can be performed above CF. The energy store component is constant, regardless of the used force, as long as the force is higher than CF. Numerous experiments have shown that CF is determined by the muscle oxidative function, while W’ depends on finite anaerobic energy sources and that it can be manipulated independently, e.g., by altering muscle phosphocreatine (PCr) stores [9]. An example of a hyperbolic force-time relationship for high-intensity exercise is shown in Figure 1. MVC-7 is the 7-second maximum voluntary contraction [N], the asymptote is the CF [N], and the colored rectangles represent the energy store component W’ [N·s], which is constant for each measurement point [10].

It is, therefore, clear that both CF and W’ are critical parameters, which are bound to decide between failure and success on long endurance routes. Recent research showed that while CP can be improved by low-intensity training below CP, as well as by interval training above CP, best results and highest time efficiency are reached when training is done precisely at CP [11]. We can, therefore, assume that Endurance Repeaters should yield the best results if done at CF.

Critical force and energy store component plot in climbing aerobic endurance

Figure 1: Illustration of the force-time relationship for high intensity exercise, according to [10].

Determination of the Critical Force and W’ for aerobic Endurance Hangboard Repeaters

The exact procedure to determine CF and W’ by using a hangboard was recently thoroughly described by David Giles, Ollie Torr, Tom Randall, and colleagues [10]. The research team examined eleven 7b – 8b+ climbers. First, they determined each climber’s 7-second MVC on a standardized Lattice Training rung (20 mm deep, 10 mm radius) in half crimp position. Then, they performed intermittent dead hang tests until failure at 80%, 60% and 45% of the climbers’ respective MVC. They found a hyperbolic relationship between the load at which the test was taken and the time to exhaustion (TTE), which is in agreement with general training theory [12].

Critical force does not depend on the maximum strength.

The research team determined the CF of the tested climbers to lie between 31.9 – 60% of their MVC, with an average of 41.0 ± 6.2%. What is interesting is that the CF does not seem to depend on the MVC. The climber with the lowest MVC of 121.7% BM (898.8 N) had the second-highest relative CF of 53.5% MVC (480.8 N),  while the strongest climber, with an MVC of 183.0% BM (1199.3 N) had a CF of 40.6% MVC (486.4 N), which was below average. In absolute terms that’s only 5.6 N, or 0.57 kg difference. The above result explains why you often see relatively weak climbers breeze up through endurance routes, while very strong boulderers, with good strength endurance, struggle after just a couple

Quick summary

Eva López IntHangs strength endurance fingerboard protocol

The Intermittent Dead Hangs protocols (IntHangs) were developed by Eva López for strength endurance fingerboard training. The idea behind this method is to mimic the activity-to-rest ratio characteristic for gripping and releasing handholds during climbing, particularly during the hardest sections of a route. Such training is thought to promote faster phosphocreatine resynthesis and enhance oxygenation during short rest periods, allowing to sustain high levels of isometric force for a longer time, which is a critical factor in lead climbing.

A low volume version of the classic Repeaters, designed to promote faster PCr resynthesis, enhance muscle oxygenation and trigger hypertrophy.

Eva López IntHangs strength endurance fingerboard protocols are quite similar to classic Hangboard Repeaters, but they are generally characterized by lower volume and longer hang and rest times. Repeaters are designed to replace a full climbing session and target multiple grip positions, which makes sense if you can’t make it to the gym or crag. IntHangs hangboard drills typically concentrate on the half crimp grip, although application to any grip position is possible. IntHangs strength endurance routines should constitute only a part of a training session and be combined with other activities. The protocol can be executed in two versions, the minimum edge with no added weight (IntHangs MED) and fixed edge with added weight (IntHangs MAW). Both methods trigger muscle hypertrophy because of the relatively long time under tension (TUT) and medium loads (60 – 80% of MVC) [1][2].

IntHangs MED strength endurance fingerboard routine details

  1. Choose an edge on which you can hang for roughly 30 seconds without added load.
    1. Typical edge depth: 8 – 22 mm.
  2. Hang for 7 – 10 seconds, rest for 3 – 30 seconds.
  3. Perform 4 – 5 hangs per set.
  4. Rest for 1 – 2  minutes between sets.
  5. Perform 3 – 5 sets.
To follow this protocol you will need a hangboard with progressively small edges, like the Progression and Transgression hangboards, developed by Eva López, or the adjustable Fingerschinder portable wooden hangboard [3][4]. Still, it should be reasonably easy to make your own board with different size wooden edges. The way I do it is that I insert 2 mm thick cardboard strips into the edge slots of my Zlagboard, as you can see in Figure 1 below [5].

IntHangs MAW strength endurance fingerboard routine details

  1. Choose an edge on which you want to train.
    1. Typical edge depth: 10 – 18 mm.
  2. For the chosen edge, determine the load allowing you to hang for roughly 30 seconds.
  3. Hang for 7 – 10 seconds, rest for 3 – 30 seconds.
  4. Perform 4 – 5 hangs per set.
  5. Rest for 1 – 2  minutes between sets.
  6. Perform 3 – 5 sets.

Figure 1: Cardboard strips in the edge slots of the Zlagboard, to adjust edge depth.

Table 1: Eva López ​IntHangs strength endurance fingerboard drill summary.

Hang test time [s]30
MVC-7 load60 - 80%
Sets3 - 5
Hangs/set4 - 5
Hang time [s]7 - 10
Rest betw. hangs [s]3 - 30
Rest betw. sets [min]1 - 2
TUT [s]84 - 250
Total time [min]4 - 22

IntHangs strength endurance fingerboard drill remarks

  • Always warm up properly before doing IntHangs strength endurance hangboard workouts.
    • Perform four to five 10-second sets, with a 5-second pause and decreasing edge depth or increasing load.
    • For the first warm-up set, the edge depth/load should allow you to hang for one minute.
      • In the case of the IntHangs MED protocol, this is roughly equivalent to an edge 5 – 10 mm deeper than the training edge from your previous session [6].
      • In the case of the IntHangs MAW protocol, this is roughly equivalent to 60% of your MVC.
  • For the first training session, the edge depth/load should be chosen in such a way so that you can hang for roughly 30 seconds.
  • 30-second tests are time-consuming and put a lot of strain on your fingers and shoulders.
    • For the MAW method, consider performing a 5 – 10-second MVC test and using 60 – 80%  of the determined maximum load.
    • For the MED method, consider using Table 2, to determine the initial edge depth.
  • You should aim to fail on the last repetition of the last set.
    • This may require adjusting the edge size/load after each set or even repetition, to control the intensity on the fly.
  • The hang time can be varied between 7 – 10 seconds.
    • Typical hang time: 10 seconds
  • The rest time between hangs can be varied between 3 – 30 seconds.
    • Typical rest time between hangs: 5 seconds.
  • The rest time between sets can be varied between 1 – 2 minutes.
    • Typical rest time between sets: 1 minute.
  • Each set corresponds to an average time required to climb through a crux section on a sport route.
  • The 5-second rest between hangs is in line with the observed minimum time of 3 – 5 seconds for oxygenation between isometric, high-intensity intermittent contractions.
  • The 1-minute rest between sets does not allow to fully recover maximum strength, which is targeted at working strength endurance.
  • The IntHangs MAW method is only recommended for advanced climbers with a lot of training experience.
  • The IntHangs strength endurance fingerboard protocols can be applied to any grip position, although the

Quick summary

Hangboard Repeaters strength endurance protocol

The knowledge as to who exactly invented the Hangboard Repeaters strength endurance protocol is lost in the darkness of history, but it’s probably the first structured hangboard protocol ever developed [1]. It’s designed to mimic the grip and relax sequence that is characteristic of climbing. The loads applied are generally low, compared to Eva López’s MaxHangs protocol, or to the Eric Hörst’s “7-53” protocol, which makes it safer for intermediate climbers [2][3]. The rest times between hangs are on the other hand very short, typically just 3 seconds. This means that your body will have to tap into both the alactic energy system, burning the creatine phosphate (PCr) stored in the muscles, but also to the lactic energy system, where anaerobic glycolysis is contributing to adenosine triphosphate (ATP) production. Enhanced blood flow will be induced to enable lactate and hydrogen ions removal, which will in turn inevitably lead to muscle pump. While Eric Hörst doesn’t consider fingerboard Repeaters to be the best strength endurance protocol, he still thinks it can be useful as a pre-season preparation for lead climbers [1].

The 7/3 Hangboard Repeaters strength endurance protocol details

  1. Choose three to seven different grip positions. Consider including:
    1. An open crimp
    2. A full crimp
    3. A three-finger pocket
    4. Two-finger pockets: index-middle (IM), middle-ring (MR) and ring-pinkie (RP) – advanced
    5. A sloper
  2. For each grip position determine your MVC and the respective hangboard training load.
  3. For each grip position:
    1. Hang for 7 seconds, rest for 3 seconds.
    2. Complete a total of 6 hangs.
  4. Rest 2 – 3 minutes and switch to the next grip position.
  5. The set is finished once all hangs for all the chosen grip positions are complete.
  6. Rest 12 – 15 minutes between sets.
  7. Complete a total of 1 – 3 sets.

Table 1: The 7/3 Hangboard Repeaters summary table.

7/3 Repeaters
MVC hang test time [s]5 - 10
MVC-7 load (beginner)40 - 50%
MVC-7 load (advanced)60 - 80%
Sets1 - 3
Positions/set3 - 7
Hang time [s]7
Rest betw. hangs [s]3
Rest betw. pos. [min]2 - 3
Rest betw. sets [min]12 - 15
TUT [s]126 - 882
Total time [min]7 - 105

Fingerboard Repeaters climbing workout remarks

  • For the maximum voluntary contraction (MVC) determination use 5 – 10-second test hangs.
  • The load for Hangboard Repeaters strength endurance protocol should be equivalent to 60 – 80% of your MVC.
  • Beginners should start with 40 – 50% of their MVC and do no more than two sets.
  • The last hangs are supposed to feel hard, and you should get pumped.
  • You should be able to complete all the hangs – use a pulley system to adjust the load.
    • If you can’t complete all the hangs, reduce weight.
    • If the hangs are too easy, add weight.
  • Alternatively, you can try doing Fingerboard Repeaters till failure (Endurance Repeaters).
  • If you want to experiment with the hang times and the rest times, you can try:
    • 6 seconds hang, 4 seconds rest
    • 5 seconds hang, 5 seconds rest
    • 5 seconds hang, 2 seconds rest

You will need to devote one or two fingerboard training sessions to determine the optimum loads for particular hang positions. It is impossible to give one general rule, as the loads will depend on the number of sets you choose to execute, the rest times between sets and hangs, and even the sequence in which you order the grip positions in a set. The time for the MVC measurement is not strictly defined, but it is normally assumed between 5 – 10 seconds [4][5]. Throughout this blog, the 7-second MVC measurement is generally used for consistency (MVC-7). 

The exact determination of the hang loads for Hangboard Repeaters climbing strength endurance protocol, or “intermittent isometric contractions” is a science in itself, and touches on the subjects of “critical force” (CF) and the “energy store component” (W’) [4]. But you don’t have to be that precise – as long as you get pumped and you’re able to complete all the hangs, you’re probably on the right track. If you want to shift the balance of the exercise more towards strength or simply adjust the intensity, you may choose a different version of Fingerboard Repeaters, such as the 6/4, 5/5, or 5/2. Another concept you may explore is doing Hangboard Repeaters till failure (Endurance Repeaters), as it was suggested by Tom Randall in the TBP interview [5][6].

The exact load determination for each grip position may be tricky, but as long as you get pumped in the end and still manage to complete all the hangs, you're on the right track.

In Figure 1 below, my example exercise logs for the 7/3 Hangboard Repeaters strength endurance protocol are shown. The routines were done on the Moon Fingerboard for six different hang positions: 3-finger sloper, 3-finger pocket, two 2-finger pockets (index-middle, middle-ring), full crimp, and half crimp [7]. First, a 30-second hang test was done for each grip position, corresponding to roughly 80% MVC-7 intensity [8]. For each position, the added/subtracted weight was recorded and subsequently adjusted. However, because of the large variety of holds used, which lead to a relatively high exercise volume, it was impossible for me to complete the routine. I recalculated the hang intensity and reduced it to 75%, based on the MVC-7 measured for each hold

Almost there...

Get updates on upcoming posts