Peer-reviewed climbing science
Entralpi was born from the need to bridge the gap between clinical biomechanics and the climbing gym. We believe that true progression requires precise measurements, which is why we calibrate and test our devices with cutting-edge methods to ensure fast, reliable data.
Key Findings (TL;DR)
- • Critical Force and Performance: Finger strength and Critical Force (CF) are the primary predictors of climbing performance, explaining up to 68% of the variance in climbing grades.
- • Training Adaptations: Intermittent, high-intensity fingerboard protocols (like 10s work / 3min rest) yield massive maximal strength gains (+28% over 8 weeks) while also improving neural recruitment.
- • Measurement Reliability: Standardized dynamometers and force plates (like Entralpi) provide highly valid, reliable data (ICC > 0.99) for tracking maximum strength and Rate of Force Development (RFD).
Scientific Validation
Extensively tested against clinical standards, the Entralpi system has been formally validated by peer-reviewed scientific studies. While typical field sensors suffer from up to 3kg of noise, Entralpi offers sub-percent accuracy, providing data previously reserved for university labs, straight to your home.
Academic Directory
More research papers are currently undergoing peer review and will be added to this directory upon publication.
Recommended Climbing Science
Berta, Michailov, Baláš, et al. (2025) Establish normative scores for finger flexor tests and compare continuous versus intermittent testing for predictive validity.
Establish normative scores for finger flexor tests and compare continuous versus intermittent testing for predictive validity.
Finger strength is the absolute primary predictor of performance (explaining 64-68% of variance). Intermittent endurance testing is superior to continuous testing for assessing climbing-specific endurance.
Bhatt, Purcell, et al. (2025) Determine the psychometric properties of the Tindeq with and without upper extremity repositioning between trials.
Determine the psychometric properties of the Tindeq with and without upper extremity repositioning between trials.
The Tindeq remains highly reliable even after arm repositioning. However, a slight mean difference between identical devices suggests athletes should use the exact same unit for tracking longitudinal progress.
Pérez-Cordero, Jerez-Mayorga, et al. (2025) Examine the reliability of finger flexor strength assessment methods across the entirety of the scientific literature.
Examine the reliability of finger flexor strength assessment methods across the entirety of the scientific literature.
Maximum Isometric Finger Strength (MIFS) tests are highly reliable. The review recommends strict international standardization utilizing 20-23mm fixed-depth edges and half-crimp grips for all future research.
Breen, et al. / Consuegra / López-Rivera (2024) Compare Passive Isometric (HIMA) dead hangs versus Active Isometric (PIMA) pulls on a fixed dynamometer.
Compare Passive Isometric (HIMA) dead hangs versus Active Isometric (PIMA) pulls on a fixed dynamometer.
Both methods significantly improve peak force and RFD. Crucially, active dynamometer pulling (PIMA) successfully reduces left/right strength asymmetries better than passive dead-hanging.
MacDougall, McClean, Aboodarda, et al. (2024) Assess the fundamental validity and reliability of the Entralpi force plate for both static and dynamic 30-repetition all-out finger flexor tests.
Assess the fundamental validity and reliability of the Entralpi force plate for both static and dynamic 30-repetition all-out finger flexor tests.
Demonstrated excellent validity (ICC 0.991, mean relative error 0.41%). Proven that the Entralpi operates as a highly accurate, low-cost alternative for peak force, peak impulse, and total impulse diagnostics.
Ruot, Jansson, et al. (Ongoing/2024) Assess max flexor versus extensor strength to correct the extreme 9:1 flexor/extensor imbalance observed in elite climbers.
Assess max flexor versus extensor strength to correct the extreme 9:1 flexor/extensor imbalance observed in elite climbers.
Demonstrates that exclusive extensor isometric training reduces physiological imbalances, presenting a primary pathway for mitigating A2 and A4 annular pulley injuries and epicondylosis.
Saeterbakken, Andersen, et al. (2024) Compare the effects of 5 weeks of dynamic finger flexor strength training versus bouldering alone.
Compare the effects of 5 weeks of dynamic finger flexor strength training versus bouldering alone.
Dynamic finger flexor training improves dynamic strength to a significantly greater extent than climbing alone, while also driving improvements in isometric finger strength.
Andersen, Michailov, et al. (2023) Compare low-load Blood Flow Restriction (BFR) training of the finger flexors against high-load resistance training.
Compare low-load Blood Flow Restriction (BFR) training of the finger flexors against high-load resistance training.
Both high-load and low-load BFR interventions equally improved maximal strength and hypertrophy. BFR provides a pathway to strength gains without subjecting the finger joints to extreme mechanical loads.
Jansson, et al. (2023) Utilize the Motherboard mounted invertedly as a vertical force plate to evaluate climbing shoe stiffness and edging biomechanics.
Utilize the Motherboard mounted invertedly as a vertical force plate to evaluate climbing shoe stiffness and edging biomechanics.
Successfully tracked joint angles and reaction forces during edging, proving the Motherboard's utility for analyzing biomechanical footwear design, stiffness impacts, and shoe sizing protocols.
McClean, MacDougall, et al. (2023) Assess the practical test-retest reliability of the 4-minute all-out Critical Force test in trained rock climbers.
Assess the practical test-retest reliability of the 4-minute all-out Critical Force test in trained rock climbers.
The protocol possesses excellent absolute reliability for peak force, but displays higher intra-individual variability for end-test force (EF) and impulse (IEF), reflecting natural human pacing and biological fluctuations.
Augste, Winkler, Künzell (2022) Optimize the testing modalities of an intermittent finger flexor endurance test (using a 7s:2s ratio) against lead climbing performance.
Optimize the testing modalities of an intermittent finger flexor endurance test (using a 7s:2s ratio) against lead climbing performance.
Tolerating a 6-9% force deviation before terminating the endurance test provides the strongest correlation with lead climbing ability, explaining 31-46% of total performance variance.
Devise, Lechaptois, Berton, Vigouroux (2022) Quantify the specific physiological adaptations resulting from 3 exact hangboard training intensities (F100, F80, F60) over a 4-week period.
Quantify the specific physiological adaptations resulting from 3 exact hangboard training intensities (F100, F80, F60) over a 4-week period.
F100 improved max strength exclusively; F60 improved endurance exclusively. The F80 protocol successfully improved both strength and endurance, identifying it as the optimal mixed-adaptation protocol for climbers.
Fryer, Baláš, et al. (2022) Estimate a "Critical Angle" (CA) for a metabolic steady state using continuous Muscle Oxygen Breakpoints (MOB) data.
Estimate a "Critical Angle" (CA) for a metabolic steady state using continuous Muscle Oxygen Breakpoints (MOB) data.
Established CA predictability on the wall. Climbing just 2° steeper than the individual's CA shifts climbers into severe exercise domains, rapidly depleting oxygen and resulting in failure within 16 minutes.
Labott, Donath, et al. (2022) Assess the validity and within/between-day reliability of the Tindeq load cell during free-hanging rung pulls and lock-offs.
Assess the validity and within/between-day reliability of the Tindeq load cell during free-hanging rung pulls and lock-offs.
The Tindeq demonstrated strong static validity (ICC = 0.99), proving it is a practical infield tracking tool for experienced climbers, provided users account for data smoothing and a ~3 kg error margin.
Vereide, Stien, et al. (2022) Investigate specific differences in peak force and Rate of Force Development (RFD) between intermediate, advanced, and elite male climbers.
Investigate specific differences in peak force and Rate of Force Development (RFD) between intermediate, advanced, and elite male climbers.
Elite climbers demonstrate significantly greater peak force (39.7% higher) and RFD (74.9% higher) than advanced climbers, establishing explosive RFD as a primary differentiator for elite progression.
Giles, Fryer, et al. (2019, 2020) Apply the traditional "Critical Power" mathematical model to intermittent isometric finger flexor actions to define "Critical Force" (CF).
Apply the traditional "Critical Power" mathematical model to intermittent isometric finger flexor actions to define "Critical Force" (CF).
Validated the CF and model for climbing. Established that CF explains 61% of sport climbing performance variance, while explains 34% of bouldering performance. Replaces arbitrary %MVC testing.
Levernier, Samozino, Laffaye (2020) Compare the force-production capacities and force-velocity-power (F-V-P) profiles of 24 high-elite bouldering, lead, and speed climbers using a progressively loaded pull-up test.
Compare the force-production capacities and force-velocity-power (F-V-P) profiles of 24 high-elite bouldering, lead, and speed climbers using a progressively loaded pull-up test.
Boulderers demonstrated significantly superior maximal power (+22-26%) and theoretical maximal velocity (+21-23%) compared to lead and speed climbers. The F-V-P profile proved highly reliable (R² > .93), establishing that elite bouldering specifically requires generating immense external force while maintaining high movement velocity under load.
Levernier & Laffaye (2019) Assess the specific neural and structural adaptations of a 4-week finger grip training program (suspensions on small holds) on maximum isometric force and the Rate of Force Development (RFD) in elite climbers.
Assess the specific neural and structural adaptations of a 4-week finger grip training program (suspensions on small holds) on maximum isometric force and the Rate of Force Development (RFD) in elite climbers.
A 4-week protocol significantly improved both maximum force (+8% on sloper crimp) and RFD (+27.5-32% in the first 200ms). The rapid RFD gains strongly suggest neuromuscular adaptations rather than muscle-tendon structural changes, highlighting the critical role of explosive neural recruitment for competitive climbers.
López-Rivera & González-Badillo (2012, 2019) Evaluate the efficacy of weight-added (MAW) versus minimum-edge (MED) dead hangs on maximum finger strength generation.
Evaluate the efficacy of weight-added (MAW) versus minimum-edge (MED) dead hangs on maximum finger strength generation.
Low-volume, maximal-load hangs (10s work, 3min rest) yield massive strength gains (up to 28% over 8 weeks). Periodizing MAW into MED optimizes both neural recruitment and tissue conditioning.
Michailov, Baláš, et al. (2018) Investigate the effect of Arm Fixation (AF) versus a free-hanging straight-arm posture on construct validity and reliability of force testing.
Investigate the effect of Arm Fixation (AF) versus a free-hanging straight-arm posture on construct validity and reliability of force testing.
Arm Fixation yields higher reliability (ICC 0.94) due to biomechanical isolation. However, non-fixation yields much higher ecological validity, predicting climbing grades significantly better ( = 0.48 vs 0.42).
