Can Light Hangboard Training Build Finger Strength? A Critical Look at the Abrahangs Study
Can Light Hangboard Training Build Finger Strength? A Critical Look at the Abrahangs Study
That question became much more interesting after a 2024 study compared traditional Max Hangs with a low-intensity, high-frequency hangboard routine commonly called Abrahangs.
The headline was appealing. Climbers performing the low-load routine improved finger strength, climbers performing Max Hangs improved finger strength, and the group performing both improved the most.
The authors conclusion was that frequent low-intensity loading could improve finger strength to a similar extent as maximal-load training. That's definitely interesting. but the study does not establish that light hangs are interchangeable with heavy finger strength training, nor does it demonstrate that the observed improvements came from tendon or pulley adaptations.
There is a lot to unravel with this study.
What are Abrahangs?
Abrahangs were developed by climbers Emil and Felix Abrahamsson following discussions around Keith Baar's research. Instead of hanging with body weight or added weight, the climber keeps the feet on the ground and applies relatively light pressure through the fingers. This is nothing new, but popularized by a Youtube following.
In the study, the routine used an 18–22 mm edge and 6 different grip positions:
a general open hang
front-three open hand
front-two open hand
middle-two open hand
front-two half crimp
middle-two half crimp
Each contraction lasted 10 seconds, generally followed by 20 seconds of recovery. The entire routine took approximately 10 minutes. Importantly, the actual force applied during these hangs was never measured. Climbers were instructed to feel only a small amount of strain in the forearms, and later the paper suggests the intended intensity to be roughly 40% of an athlete’s maximum. That’s the first major limitation.
How did the researchers study adaptation?
This wasn't a randomized controlled trial. The researchers retrospectively (looking back) analyzed training data from climbers using the Crimpd app. That means, the users had voluntarily, and hopefully accurately, logged their workouts and completed at least two finger strength tests separated by at least 4–16 weeks. That’s a huge difference between testing sessions.
As a reflection of total training performed/logged, the climbers were then categorized into four groups:
Climbing Only: Little, or no logged Abrahang or Max Hang training.
Abrahangs Only: At least three Abrahang sessions per week and fewer than 0.5 Max Hang sessions per week.
Max Hangs Only: At least 0.5 Max Hang sessions per week and fewer than three Abrahang sessions per week.
Both: At least three Abrahang sessions per week plus at least 0.5 Max Hang sessions per week.
The final analysis included 526 climbers, mostly males, and had a wide range climbing levels (intermediate to elite).
How was finger strength measured?
Climbers performed the test on their own hangboard using approximately a 20 mm edge in a strict half-crimp position. They progressively added or removed weight with a pulley system until determining the greatest total load they could hold for 7 seconds. That total load was expressed relative to body weight (total load / body weight).
An important confounder is that the Max Hang protocol closely resembled the test. 6 × 10-second hangs at 85–95% of the tested maximum, with two minutes of recovery.
The Abrahangs protocol was very different. A significatnly lower intended force, more total contraction time, multiple grip positions, and a higher training frequency. So they’re not simply comparing heavy versus light versions of the same exercise. They’re comparing two totally different training strategies.
What actually happened?
The average change in S/W ratio was approximately:
Climbing only +0.2%
Abrahangs +2.5%
Max Hangs +3.2%
Both+5.8%
The effect sizes compared with the climbing only group were approximately:
Abrahangs: d = 0.29
Max Hangs: d = 0.45
Both: d = 0.79
At first glance, this looks amazing. Low load helped, high load helped slightly more, and doing both helped considerably more. But this needs to be interpreted carefully.
Did Abrahangs really perform as well as Max Hangs?
This is where the paper's conclusion is stronger than the data justifies. There was no statistically significant difference between the Abrahangs and Max Hangs groups. As a result, the authors described the improvements as “equivalent.”
But, failing to find a difference is not the same thing as proving equivalence. This is message manipulation. To establish that two interventions are genuinely equivalent, a study needs to be designed prospectively as an equivalence or non-inferiority trial with predefined margins and sufficient statistical power. This wasn't even close to that.
More importantly, when they compared the change in S/W ratio against the climbing-only group, the Abrahang group's +2.5% change was not significantly different from climbing only (p = .1216). Conversely, the Max Hang group's +3.2% change was significantly different from climbing only (p = .0005). And has been validated in the climbing literature.
That does not mean Abrahangs didn't do anything. That group showed a within group pre/post improvement, but it makes the headline “low loading was just as effective as Max Hangs” incredibly suspicious.
My biggest problem: we have no idea how light the “light” training was
The Abrahang protocol is usually discussed as approximately 40% of an athlete’s maximum. But as we’ve mentioned, force was never directly measured. Climbers kept their feet on the floor and self-selected how hard they pulled based on sensation. RPE wasn’t even used as a target prescription, which makes more sense.
The researchers do acknowledge this directly. They didn’t not know how much weight was actually transferred from the feet into the fingers. But that's a massive limitation if the central argument is whether 40% loading builds maximal finger strength? We have no idea that these climbers trained at 40%. Some might have trained at 25%, some at 50%, and some at 70%. As someone who’s tested hundreds of climbers, I am very comfortable suggesting that climbers don’t know what 40% feels like.
The two programs had very different doses
Abrahangs contained approximately 200 seconds of contraction time per session across the multiple grips.
Max Hangs contained approximately 60 seconds of contraction time per session.
And to qualify for the Abrahang group, climbers averaged at least three sessions per week, whereas the Max Hang classification required only at least 0.5 sessions per week.
There was no matching the training frequency, total contraction time, force-time integral, total mechanical work, or training volume.
They were examining entirely different stimuli, and definitely questions the conclusion that 40% intensity improves max strength as effectively as 90% intensity does.
What about the group that did both?
The combined group improved by approximately 5.8%, compared with 2.5% for Abrahangs and 3.2% for Max Hangs. Numerically, that's almost precisely 2.5 + 3.2 = 5.7%. The authors creatively described this as an additive effect. That's a highly exaggerated observation, and I would not jump from that result to their proposed physiological explanation.
Put simply, the combined group performed more specific finger training.
They weren't randomized, and there was no control over climbing, additional finger training, previous training experience, and motivation. Additionally, the rationale for some individuals to chose to both protocols wasn't known.
So one plausible explanation is that different stimuli produced additive adaptations.
Another equally plausible explanation is that people who did more finger training improved more.
This study cannot separate those explanations.
Did Abrahangs strengthen the tendons and pulleys?
We have no idea, but i’m highly suspicious. This is the part of the explanation that deserves the most caution. Their proposed mechanism behind Abrahangs is that frequent low-load contractions stimulate the connective tissues involved in transmitting finger-flexor force. Essentially, adaptations in tendon, tendon sheath (fascia), and annular pulleys.
But the study measured none of them. There was no ultrasound, MRI, tendon stiffness measurement, pulley thickness measurement, tendon cross-sectional area, collagen synthesis measurement, muscle imaging, or even EMG assessment. The only outcome was performance on the finger strength test, which is a low bar to say it nicely.
Increases in reflect:
muscle adaptation/recruitment
neural adaptation/firing rate
improved coordination
connective-tissue adaptation
grip-specific adaptations
or some combination
We simply cannot say, but they go out on a limb suggesting that within this timeframe, and at 40% intensity, there are significant connective-tissue adaptations. That is not a finding of this study.
Abrahangs also trained more more grip types
Another problem here is that the strength test and Max Hang training were performed primarily in a four-finger half crimp. Abrahangs exposed climbers to several combinations of open-hand, two-finger, three-finger and half-crimp loading. That means Abrahangs weren't just a low-intensity version of the tested movement. They provided a relatively large amount of training across multiple grip types. That can be useful in climbing training, but again, it makes it unreasonable to attribute the results to intensity alone.
What does the climbing research tell us?
Other climbing research provides a useful comparison.
A 2022 trial assigned experienced climbers to finger training at 60%, 80% or 100% of maximal finger strength for four weeks.
Maximal finger strength increased significantly in the 80% and 100% groups, but not in the 60% group.
The 60% and 80% groups, however, improved measures of stamina and endurance.
That study directly discredits the idea that low intensity is equivalent to high intensity for finger strength.
Intensity definnitely matters.
A 2026 trial studied advanced to elite climbers performing finger training for five weeks.
One group trained at approximately 40% MVC with blood-flow restriction to failure.
Another grouptrained at approximately 75% MVC without BFR.
MVC (max force) improved by approximately 9% in the low-load BFR group and 13% in the high-load group.
There was no significant change in the control group.
Plenty of non-climbing research has demonstrated that training at 30-50% under blood-flow restriction to failure produces strength gains, but that is a very different internal stimulus than a 40% isometric load with the feet on the floor. BFR is quite an intense stimulus.
Are Abrahangs safer or better for injured fingers?
This study cannot answer that question, but it uses a word salad to make it appear like it does. There was certainly no prospective injury outcome measured. The researchers do suggest that future studies are needed to determine whether the protocol improves finger health or reduces injury risk, even though they lean into that narrative.
So no, we should not use this paper as evidence that Abrahangs prevent pulley injuries, heal tendons, strengthen injured connective tissue, or make daily finger loading inherently safe or a good idea. Low-load exercise can necessary in ra ehabilitation context, but rehabilitation requires the load to match the tissue, stage of injury, and the individual. Assuming that “low intensity” is synonymous with “therapeutic” is simply ridiculous.
So are Abrahangs useful?
Potentially, but there’s nothing special about the time under tension, loading frequency, and variable grip positions. It’s simply a warmup-type stimulus to the fingers, that can be used in the broader context per individual as needed. I think the most useful interpretation of this study is much simpler than what the authors try to squeeze out of this paper.
Finger strength might be trainable across a broader range of loading intensities than climbers traditionally have assumed.
High-intensity loading isn’t the only way to expose the fingers to a usable training stimulus.
Frequent, relatively low-fatigue loading may be indicated when:
you want additional finger volume when you’re not climbing (traveling, covid, etc.)
you have a NEED to expose the fingers to multiple grip positions
you’re in season, and are getting a high climbing stimulus outside already
you’re coming back from an injury, or simply warming up for a climbing session
That’s all very different from saying “40% hangs build maximal finger strength just as well as 90% hangs.”
I personally think that’s ridiculous.
What would I do with this practically?
If maximal finger strength is the primary goal, high-intensity loading still has the strongest physiological rationale and support.
I wouldn't replace heavy strength work with Abrahangs. Definitely not because of this study. But I also wouldn't dismiss the utility of low-load finger training, because I’ve done it for over a decade with my clients. But it needs to be have a specific rationale for the individual to reach their training goals. I certainly would not suggest that all climbers do Abrahangs regularly for finger health.
Final takeaway
The Abrahangs study raises more questions than it answers. Their data simply suggests that climbers who frequently performed low-load finger training can improve finger strength. That is, if the finger strength testing was not normal day-to-day variability.
It did not establish that
40% loading is equivalent to 85–95% loading
that the improvement came from connective-tissue adaptation
Abrahangs reduce injury risk
or combining light and heavy training produces a unique physiological effect beyond simply performing more training
References
Gilmore NK, Klimek P, Abrahamsson E, Baar K. Effects of Different Loading Programs on Finger Strength in Rock Climbers. Sports Medicine - Open. 2024;10:125. PMID: 39560837.
Devise M, Lechaptois C, Berton E, Vigouroux L. Effects of Different Hangboard Training Intensities on Finger Grip Strength, Stamina, and Endurance. Front Sports Act Living. 2022;4:862782. PMID: 35498522.
Perrin TP, et al. Low-Load Blood-Flow Restricted Resistance Training Improves Finger Flexor Muscle Function in Experienced Climbers: A Randomized Controlled Trial. Med Sci Sports Exerc. 2026;58(8):1637–1650. PMID: 41882800.