Research library
Every study cited on this site, with the full reference, a link, who was tested, the numbers we use, and the limits. These are the only sources allowed under a "Measured" label.
How to use the library
Each entry says who was measured. Read every number with that in mind: a value from 11 elite adult men isn't a value for a beginner, and none of the adult values apply to children. Where we couldn't read the full paper, the entry says so.
The study explorer below charts the published values with group, sample size and spread where available.
How to read the explorer
Bars are means; whiskers are ±1 standard deviation where the paper reports it. A missing whisker means we didn't have the spread, not that there was none. Use the toggles to compare groups measured in a comparable way within a study, or the 2012 and 2018 competition data. The table under each chart shows the same numbers as text.
Energy and forearm physiology
Bertuzzi et al. 2007: energy systems on indoor routes
Bertuzzi RC, Franchini E, Kokubun E, Kiss MA. Energy system contributions in indoor rock climbing. Eur J Appl Physiol 2007;101(3):293–300. doi:10.1007/s00421-007-0501-0
13 adult climbers: 6 elite and 7 recreational.
aerobic / phosphocreatine / glycolytic share, elite: easy 41.5 / 41.1 / 17.4 %, moderate 45.8 / 34.6 / 21.9 %, difficult 41.9 / 35.8 / 22.3 %; recreational, easy: 39.7 / 34.0 / 26.3 %. Easy-route energy cost 40.3 kJ (elite) vs 60.1 kJ (recreational).
very small groups; indoor routes in one lab; shares were calculated from oxygen uptake, post-exercise oxygen and blood lactate, each with its own assumptions; recreational climbers climbed only the easy route.
Fryer et al. 2015: oxygen recovery in the forearm
Fryer SM, Stoner L, Dickson TG, Draper SB, McCluskey MJ, Hughes JD, How SC, Draper N. Oxygen recovery kinetics in the forearm flexors of multiple ability groups of rock climbers. J Strength Cond Res 2015;29(6):1633–1639. doi:10.1519/JSC.0000000000000804
44 adult men recruited, 38 analysed, in four groups: non-climbing controls, intermediate, advanced and elite climbers (by self-reported grade).
time to half recovery of forearm oxygen in the deep finger flexor (FDP) after a sustained 40 % grip to failure: 8 s elite, 47 s intermediate, 95 s controls; after repeated grips: 8, 83 and 93 s.
men only; open crimp on a fingerboard, not climbing; passive recovery with the arm off the wall; near-infrared spectroscopy measures a small area of muscle, and later work suggests forearm sensors mostly see the superficial finger flexor rather than the deep one (Vandenhaute et al. 2026). We read the accepted manuscript, which doesn't include the tables, so the advanced group's half-times and the SDs aren't shown here.
Baláš et al. 2016: shaking low vs hand over the hold
Baláš J, Michailov M, Giles D, Kodejška J, Panáčková M, Fryer S. Active recovery of the finger flexors enhances intermittent handgrip performance in rock climbers. Eur J Sport Sci 2016;16(7):764–772. doi:10.1080/17461391.2015.1119198
22 adult rock climbers (sport climbers, boulderers, lower-grade climbers).
shaking beside the body vs hand over the hold: +22 % repeated-grip time, +28 % force-time integral, +32 % faster re-oxygenation. Repeated-to-continuous time ratio: 2.02 sport climbers, 1.74 boulderers, 1.25 lower-grade climbers.
a lab grip test at 60 % of maximum, not climbing; we used the abstract, which doesn't give group sizes or SDs.
Barnes 1980: when forearm blood flow stops
Barnes WS. The relationship between maximum isometric strength and intramuscular circulatory occlusion. Ergonomics 1980;23(4):351–357. doi:10.1080/00140138008924748
adults in a handgrip study; we didn't access the full paper or its sample size.
forearm blood flow cut off at roughly 45–75 % of maximum grip force, as summarised for climbers by MacLeod et al. 2007.
old handgrip research, not climbing; the range is wide because people and muscles differ.
MacLeod et al. 2007: finger endurance in climbers
MacLeod D, Sutherland DL, Buntin L, Whitaker A, Aitchison T, Watt I, Bradley J, Grant S. Physiological determinants of climbing-specific finger endurance and sport rock climbing performance. J Sports Sci 2007;25(12):1433–1443. doi:10.1080/02640410600944550
11 intermediate adult climbers and 9 non-climbers; continuous and intermittent grips at 40 % of maximum.
cited as the climbing source for the 45–75 % occlusion range.
small sample; intermediate climbers only.
Giles et al. 2019: measuring critical force
Giles D, Chidley JB, Taylor N, Torr O, Hadley J, Randall T, Fryer S. The determination of finger-flexor critical force in rock climbers. Int J Sports Physiol Perform 2019;14(7):972–979. doi:10.1123/ijspp.2018-0809
11 adult male climbers, advanced to elite (red-point French 7b–8b+).
critical force 41.0 % of maximum (SD 6.2), 425.7 N (SD 82.8); W′ 30,882 N·s (SD 11,820).
11 men; the single-session test agreed well with the multi-session test for CF but less well for W′.
Giles et al. 2021: critical force and climbing ability
Giles D, Hartley C, Maslen H, Hadley J, Taylor N, Torr O, Chidley J, Randall T, Fryer S. An all-out test to determine finger flexor critical force in rock climbers. Int J Sports Physiol Perform 2021;16(7):942–949. doi:10.1123/ijspp.2020-0637
129 adult climbers (61 women, 68 men), intermediate to higher elite.
CF relative to body mass explained 61 % of sport and 26 % of bouldering ability; W′ per kg 7 % and 34 %; combined 66 % and 44 % (adjusted for sex).
self-reported grades; cross-sectional, so it shows association, not cause; dominant arm only.
Blood flow, arm position and measurement
Fryer et al. 2015b: blood flow between grips
Fryer S, Stoner L, Lucero A, Witter T, Scarrott C, Dickson T, Cole M, Draper N. Haemodynamic kinetics and intermittent finger flexor performance in rock climbers. Int J Sports Med 2015;36(2):137–142. doi:10.1055/s-0034-1385887
38 adults in four groups: non-climbing controls, intermediate, advanced and elite climbers.
forearm blood flow in the 3 s release between 10 s grips at 40 % of maximum: 656, 701, 764 and 971 ml/min (controls, intermediate, advanced, elite). Elite climbers deoxygenated the finger flexors more during contractions.
a fingerboard test, not climbing; SDs not given in the abstract.
Fryer et al. 2016: oxygen half-time and grade
Fryer S, Stoner L, Stone K, Giles D, Sveen J, Garrido I, España-Romero V. Forearm muscle oxidative capacity index predicts sport rock-climbing performance. Eur J Appl Physiol 2016;116(8):1479–1484. doi:10.1007/s00421-016-3403-1
46 adult sport climbers of a range of abilities.
a 1 s shorter oxygen half-time after 3–5 minutes of cuff occlusion was associated with a 0.65 grade higher red-point (adjusted R² 0.53), adjusted for age, sex, BMI and training experience.
cross-sectional (association, not cause); self-reported grades.
Thompson et al. 2015: climbers' arteries
Thompson EB, Farrow L, Hunt JE, Lewis MP, Ferguson RA. Brachial artery characteristics and micro-vascular filtration capacity in rock climbers. Eur J Sport Sci 2015;15(4):296–304. doi:10.1080/17461391.2014.940560
8 adult climbers and 8 untrained controls.
brachial artery diameter at rest 4.30 vs 3.79 mm; peak blood flow after 5 minutes of cuff occlusion 1136 vs 651 ml/min; flow-mediated dilation similar (9.2 vs 8.7 %).
very small groups. The abstract also reports a difference in capillary filtration capacity, but its numbers appear in the opposite order to its text, so we don't quote them.
Štěpánová et al. 2026: arm position and oxygen recovery
Štěpánová A, Čikotová E, Vandenhaute S, Fryer S, Baláš J. Arm position, but not laterality or climbing ability, modulates forearm oxygen recovery dynamics in rock climbers. BMC Sports Sci Med Rehabil 2026 (published 18 September 2026, early version). doi:10.1186/s13102-026-02089-7 (open access)
51 adult men: 20 advanced to higher elite, 21 intermediate, 10 non-climbers.
arm elevated (180° shoulder flexion) vs lying with the arm at heart level: half-time of recovery 2.44 times longer, recovery rate about 61 % lower. No effect of climbing ability or arm dominance; large individual differences.
men only; a cuff test, not climbing; we read the abstract of the accepted early version.
Heinzl et al. 2025: forearm height and blood flow
Heinzl L, Risse S, Schwarzbach H, Hildebrandt O, Koehler U, Koenig AM, Mahnken AH, Kinscherf R, Hildebrandt W. Forearm elevation impairs local static handgrip endurance likely through reduction in vascular conductance and perfusion pressure: revisiting Rohmert's curve. Sci Rep 2025;15:1250. doi:10.1038/s41598-024-83939-7 (open access)
14 healthy young men (not climbers).
at a 15 % grip, peak forearm blood flow 11.1 ml/min/100 ml with the forearm 27.5 cm above heart level, 15.6 at heart level and 14.2 at 27.5 cm below; hold time 390, 456 and 476 s. Grips of 20–70 % were unaffected by position.
handgrip, not climbing; light grips only showed the effect.
Celermajer et al. 1994: age and blood-vessel function
Celermajer DS, Sorensen KE, Spiegelhalter DJ, Georgakopoulos D, Robinson J, Deanfield JE. Aging is associated with endothelial dysfunction in healthy men years before the age-related decline in women. J Am Coll Cardiol 1994;24(2):471–476. doi:10.1016/0735-1097(94)90305-0
238 healthy adults (103 men, 135 women), aged 15–72, not climbers.
flow-mediated dilation preserved in men up to about 40, then declining 0.21 %/year; in women stable until the early 50s, then declining 0.49 %/year.
cross-sectional; the upper-arm artery, not forearm muscle; general population.
Rossman et al. 2017: exercise and blood-vessel ageing
Rossman MJ, Kaplon RE, Hill SD, McNamara MN, Santos-Parker JR, Pierce GL, Seals DR, Donato AJ. Endothelial cell senescence with aging in healthy humans: prevention by habitual exercise and relation to vascular endothelial function. Am J Physiol Heart Circ Physiol 2017;313(5):H890–H895. doi:10.1152/ajpheart.00416.2017
young sedentary (about 22 years, n = 9), older sedentary (about 60, n = 12) and older exercising adults (about 57, n = 13).
ageing markers in blood-vessel lining cells 116–128 % higher in older sedentary than young sedentary adults, and not raised in older exercising adults.
small groups; cells taken from a forearm vein; not climbers.
Vandenhaute et al. 2026: where forearm sensors look
Vandenhaute S, Podlipný O, Čikotová E, Forrer T, Baláš J. Methodological considerations for near-infrared spectroscopy assessments in rock climbers: impact of forearm morphology and optode placement. Front Sports Act Living 2026;8:1845130. doi:10.3389/fspor.2026.1845130 (open access)
climbers: 28 for forearm ultrasound, 22 for a sensor-placement test.
the border between the superficial and deep finger flexors was 17.6 mm (SD 4.0) deep, so most NIRS signal comes from the superficial flexor; sensor orientation changed some readings (mean oxygenation 5.5 % higher across the fibres) but not the cuff-test half-time.
one device type; recommendations for research setups.
Perrey et al. 2024: muscle oximetry in sport
Perrey S, Quaresima V, Ferrari M. Muscle oximetry in sports science: an updated systematic review. Sports Med 2024;54(4):975–996. doi:10.1007/s40279-023-01987-x (open access)
a systematic review of sports studies using NIRS.
130 studies used wearable devices during exercise, 40 % with the PortaMon and 24 % with the Moxy; main limitations are penetration depth, spatial resolution and fat tissue.
a review across sports; few climbing studies.
Body size, strength and sex differences
Watts 2004: physiology of difficult rock climbing
Watts PB. Physiology of difficult rock climbing. Eur J Appl Physiol 2004;91(4):361–372. doi:10.1007/s00421-003-1036-7
a review of studies on climbers at 5.11/6c and harder.
high-level climbers are small in stature with low body mass and body fat; absolute strength isn't unusual, but strength-to-mass is high.
a narrative review from 2004.
Mermier et al. 2000: what explains sport-climbing performance
Mermier CM, Janot JM, Parker DL, Swan JG. Physiological and anthropometric determinants of sport climbing performance. Br J Sports Med 2000;34(5):359–365. doi:10.1136/bjsm.34.5.359
44 adult climbers (24 men, 20 women), 5.6–5.13c.
a trainable component explained 58.9 % of performance; body measurements (height, weight, leg length, arm span, body fat) 0.3 %; flexibility 1.8 %.
performance measured on two wall routes in one study; principal-component grouping depends on the variables chosen.
Laffaye et al. 2016: strength, anthropometry and fatigue
Laffaye G, Levernier G, Collin JM. Determinant factors in climbing ability: influence of strength, anthropometry, and neuromuscular fatigue. Scand J Med Sci Sports 2016;26(10):1151–1159. doi:10.1111/sms.12558
41 climbers: 15 novice, 16 skilled, 10 elite.
trainable variables explained 46 % of climbing ability; anthropometry and muscle characteristics under 4 %.
cross-sectional; small elite group.
Philippe et al. 2012: elite female and male climbers
Philippe M, Wegst D, Müller T, Raschner C, Burtscher M. Climbing-specific finger flexor performance and forearm muscle oxygenation in elite male and female sport climbers. Eur J Appl Physiol 2012;112(8):2839–2847. doi:10.1007/s00421-011-2260-1
12 elite climbers (women and men) and 12 non-climbers; tests at 40 % of maximum.
strength and strength-to-weight higher in climbers and in men; faster re-oxygenation in climbers without a sex difference; strength-to-weight vs on-sight grade r² = 0.946 in the female climbers.
very small subgroups.
Caro-Betancur et al. 2026: forearm muscle thickness
Caro-Betancur HE, Bravo-Aguilar M, Estrella-Riquelme M, Jiménez-Parra D, González-de-la-Flor Á, López-López D, García-Mateos M, Miñambres-Martín D, Jaén-Crespo G, Romero-Morales C. Forearm muscle and nerve morphology differs by sex and predicts climbing style in recreational climbers. Sci Rep 2026. doi:10.1038/s41598-026-62497-0
50 recreational climbers (33 men), ultrasound.
men had thicker forearm flexors even after adjusting for body size and training; each 1 mm of deep-flexor thickness went with 57 % higher odds of being a lead climber (OR 1.573).
cross-sectional; recreational climbers; thickness is not the same as endurance.
Gonzales & Scheuermann 2007: sex and repeated handgrips
Gonzales JU, Scheuermann BW. Absence of gender differences in the fatigability of the forearm muscles during intermittent isometric handgrip exercise. J Sports Sci Med 2007;6(1):98–105. PMC3778706 (open access)
11 women and 11 men (about 24 years), not climbers.
at 50 % of maximum, 5 s on / 5 s off, time to failure 793 s (women) vs 685 s (men), not significantly different, despite maximum grip of 341 vs 480 N.
handgrip, not climbing; small groups.
Hunter 2014: sex differences in fatigability
Hunter SK. Sex differences in human fatigability: mechanisms and insight to physiological responses. Acta Physiol 2014;210(4):768–789. doi:10.1111/apha.12234
a review.
women are usually less fatigable than men in similar-intensity isometric contractions; the difference depends on the task.
general review, not climbing-specific.
Mountjoy et al. 2023: Relative Energy Deficiency in Sport
Mountjoy M, Ackerman KE, Bailey DM, Burke LM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073–1098. doi:10.1136/bjsports-2023-106994
an expert consensus statement.
none; cited for the warning that low energy availability harms health and performance.
covers all sports, not climbing specifically.
Competition and training
Arbulu et al. 2015: time-motion of a lead final
Arbulu A, Usabiaga O, Castellano J. A time motion analysis of lead climbing in the 2012 men's and women's world championship finals. Int J Perf Anal Sport 2015;15(3):924–934. doi:10.1080/24748668.2015.11868841
16 ascents by adult elite competitors (8 men, 8 women), 2012 World Championship lead final, from video.
route time 220 s (SD 82) men, 356 s (SD 93) women. Hand contact per hold 8.5 s (women) and 7.0 s (men), as reported by Winkler et al. 2022.
one final; we read the abstract and Winkler's summary, not the full paper. See "Corrections" below for the contact and reach figures.
Winkler et al. 2022: load structure of international competitions
Winkler M, Künzell S, Augste C. The load structure in international competitive climbing. Front Sports Act Living 2022;4:790336. doi:10.3389/fspor.2022.790336 (open access)
2018 World Cup and World Championship video; lead: 80 attempts (37 by 12 women, 43 by 25 men).
semi-final and final route time 235 s (SD 68) men, 261 s (SD 56) women, 26 attempts each; hand contact per hold 6.3 s (men), 5.6 s (women).
one season; route-setting and rules keep changing.
Bosquet et al. 2007: tapering
Bosquet L, Montpetit J, Arvisais D, Mujika I. Effects of tapering on performance: a meta-analysis. Med Sci Sports Exerc 2007;39(8):1358–1365. doi:10.1249/mss.0b013e31806010e0
27 studies of trained athletes, mostly endurance sports.
best results with about two weeks of tapering, training volume reduced by 41–60 % (exponentially), intensity and frequency unchanged.
no climbing studies; the best taper for climbers hasn't been measured.
Fingers: pulleys and growth plates
Schweizer 2001: crimp grip mechanics
Schweizer A. Biomechanical properties of the crimp grip position in rock climbers. J Biomech 2001;34(2):217–223. doi:10.1016/s0021-9290(00)00184-6
16 fingers of 4 adults, in the living hand.
A2 pulley load about 3 times the fingertip force in a crimp; up to 116 N; a warm-up increased bowstringing over A2 by 0.6 mm (30 %).
four people; it measured mechanics, not injury risk.
Vigouroux et al. 2006: tendon and pulley forces by grip
Vigouroux L, Quaine F, Labarre-Vila A, Moutet F. Estimation of finger muscle tendon tensions and pulley forces during specific sport-climbing grip techniques. J Biomech 2006;39(14):2583–2592. doi:10.1016/j.jbiomech.2005.08.027
a three-dimensional finger model with measured inputs (EMG and forces); the abstract doesn't give the number of participants.
A2 pulley force 36 times lower in a slope (open) grip than in a crimp; A4 4 times lower.
model estimates, not direct measurements of pulley force.
Miro et al. 2021: pulley injuries review
Miro PH, vanSonnenberg E, Sabb DM, Schöffl V. Finger flexor pulley injuries in rock climbers. Wilderness Environ Med 2021;32(2):247–258. doi:10.1016/j.wem.2021.01.011
a narrative review of published research.
pulley injuries are the most common overuse injury in climbers; the crimp grip is the mechanism; A2–A4 most at risk; ultrasound as the first scan.
a review, not new data.
Schöffl et al. 2022: growth-plate injuries in adolescent climbers
Schöffl V, Schöffl I, Flohé S, El-Sheikh Y, Lutter C. Evaluation of a diagnostic-therapeutic algorithm for finger epiphyseal growth plate stress injuries in adolescent climbers. Am J Sports Med 2022;50(1):229–237. doi:10.1177/03635465211056956
27 adolescent climbers with 37 injuries (mean age 14.7, SD 1.5; 19 male, 8 female; 66.7 % competitive), over four years.
growth-plate stress injuries are the most frequent sport-specific injury in adolescent climbers; 28 of 37 were Salter-Harris III fractures.
a case series of injured climbers from specialist clinics; it can't say how common the injury is among all young climbers.
Meyers et al. 2020: returning to climb after a growth-plate fracture
Meyers RN, Schöffl VR, Mei-Dan O, Provance AJ. Returning to climb after epiphyseal finger stress fracture. Curr Sports Med Rep 2020;19(11):457–462. doi:10.1249/jsr.0000000000000770
a review with a proposed return-to-climb protocol.
growth-plate stress fractures are the most common injury in youth climbers; campus board training is a known risk factor.
expert review and proposal, not a trial.
Guidance sheets (not studies)
American Orthopaedic Society for Sports Medicine, reviewed September 2025. Growth-plate stress fractures are the most common injury in youth climbers; growth-spurt ages of about 11–14 (girls) and 12–16 (boys); no double-dyno campusing until 18; no added weight; see a professional for finger pain lasting more than 24 hours or recurring for more than a week. sportsmed.org/rock-climbing
British Mountaineering Council, v1.0, February 2024, reviewed by clinicians including V. Schöffl. Fingers finish growing around 17; the middle joint (PIP) is most affected; dorsal tenderness; "Pain = STOP"; X-rays can look normal when an MRI shows the fracture; typically 6–8 weeks off with re-imaging. BMC guide (PDF)
Corrections made while verifying
the figures of 9.0 s hand contact and 2.4 s reach are often attributed to Arbulu et al. 2015, but Winkler et al. 2022 report them from an earlier study of national and international finals in 1989–1993. Arbulu et al. reported hand contact of 8.5 s (women) and 7.0 s (men). We use the latter.
the current climbing sheet is marked "Reviewed September 2025", not 2026.
the 8 / 47 / 95 s half-times are after a sustained hold; after repeated grips they were 8 / 83 / 93 s. Both are now stated.
The evidence
- Measured Every entry above links to its source. Numbers on the site match the values listed here.
- Coaching practice Anything on the site not covered by this library is labelled coaching practice.
- Model The interactive models are documented on the pages that use them; the study explorer itself does no modelling.