Mono Training for Climbers: Start Safely

Train monos one finger at a time, starting at 50% of the two-finger maximum, and stop at any pain. Pulling hard on a single finger carries a real injury risk, including lumbrical tears. The protocol is my own practice, deliberately conservative and not tested.

Monos turn up as a natural part of climbing, yet few climbers train them. I have trained them this way since 2020; below, what is documented is kept apart from what is my belief.

What is the injury risk with monos?

Pulling a large load through one finger is traumatic. The injury most associated with it is a tear of the lumbricals, the small muscles in the middle of the hand that originate on the flexor tendons. A 2024 cadaver study explains the mechanism: when one finger’s deep flexor is loaded while the others glide in a different direction, a shear force acts between the tendons and the lumbrical can tear off. In the lab it failed at a load of about 11 kg on the little finger’s tendon (Carnicero et al.). Lumbrical tears are described as a risk of pockets and single-finger pulls, while finger pulley injuries remain the most common sport-specific finger injury in climbing (Vagy et al., 2026; Promer et al., 2026).

The documented risk position is one finger loaded in flexion while its neighbours are held straight: the deep flexor tendons then glide in opposite directions and shear the lumbrical between them (Schweizer, 2003; Carnicero et al., 2024). The 2020 version of this article advised lifting the free fingers out of the way, which creates exactly that position. Let them stay relaxed and loosely curled instead; that tip is coach practice drawn from the mechanism, not a tested rule.

How do you train monos?

Parameter	Setting
Test	Measure each finger alone, leaving a small margin before you feel anything in the middle of the hand
Load	50% of the maximum strength of the two-finger pair
Free fingers	Relaxed and loosely curled, never held straight
Control	A tool that shows the force on the hold, so you train at a known force and can adjust it mid-set. Portable mono holds also isolate the fingers but are riskier
Block	One month at that low intensity, then a week off and a retest
Stop rules	Any pain stops the session; do not push through pain to finish a set. If the pain lasts, see a physiotherapist

Go gradually, so the tissues of the hand can adapt. One way to keep the habit is to slot this light work into the end of your warm-up; the daily training routine includes very light single-finger work.

Does mono strength transfer to other grips?

This is my reasoning, not a finding: I know of no study that tested it. Grips where the fingers sit at different heights isolate the strength of each flexor, so stronger individual fingers should help there. They may also help stabilise the hand, and finger locks in cracks often demand a strength similar to a two-finger pocket. What is measured is narrower: finger strength is the strongest physical predictor of climbing ability in a 2025 study of 307 climbers (Berta et al.), but its tests did not include single-finger pulls.

Who should train monos?

Climbers for whom monos are a weak link: if a grip repels you, that may be a reason to train it, once your climbing, physique and goals point there. For all-finger strength, max hangs are the best-studied method. Anyone with current finger or hand pain should not start.

Do this in Entralpi

The finger strength test measures each finger alone, one hand at a time, and shows your weakest finger. Workouts on one finger use that test for that finger by themselves, and estimate from your max strength value in Settings until you have tested it. Start a workout from the Train tab or build your own at the load you chose. Without the plate, the timer runs the intervals, but you can’t see the force, so stay far below your limit.

Sources

Schweizer A (2003). Lumbrical tears in rock climbers. Journal of Hand Surgery (British Volume), 28(2), 187-189.
Carnicero N, et al. (2024). Pathomechanics of lumbrical and flexor digitorum profundus muscle tears in climbers: a cadaveric model. Journal of Biomechanics.
Vagy J, et al. (2026). Musculoskeletal injuries in rock climbing: a scoping review. BMJ Open Sport & Exercise Medicine.
Promer HJ, Chen KC, Chang EY (2026). Imaging of injuries in rock climbers. Skeletal Radiology.
Berta P, et al. (2025). Validity and normative scores of finger flexor strength and endurance tests estimated from a large sample of female and male climbers. Journal of Sports Sciences, 43(3).