Author(s): EXEL, J., LEDROIT, C., MUSIL, C., GÁSPARI, A., BACA, A., KAINZ, H., Institution: UNIVERSITY OF VIENNA, Country: AUSTRIA, Abstract-ID: 354

INTRODUCTION:
Isometric finger endurance is key for climbing performance [1, 2] and methods for estimating forearm muscles’ aerobic capacity is an important tool to optimize training organization. Previous work has proposed a method for determining this capacity, based on percentages of maximal voluntary isometric contractions of the forearms and fixed hold depth [3]. However, climbing often present variety of holds sizes, shapes, and depths to challenge climbers’ skill abilities while performing and understanding the relationship between climbers’ tolerance to exercise in different hold depths is still unknown. A first step towards that is determining an assessment protocol that can exhibit a real change in performance instead of a change consistent with the measurement error. Thus, the aim of this study was to assess the consistency of the force measurements in the test-retest of an intermittent exercise of isometric body-weight dead hangs to exhaustion performed in 4 different hold depth.
METHODS:
Twenty climbers (28.77.2 years, 175.97.9 cm height, 67.79.9 kg weight, 21.41.6 IRCRA scale climbing ability level) visited the lab in four occasions for testing, with a minimum interval of 48 hours between sessions. The test consisted of intermittent isometric dead hangs to exhaustion, with a 7:3 s work:relief ratio in one of the 2 pairs of holds with different depths: 10 - 30 mm, and 15 - 20 mm. The sequence of hold pairs was assigned randomly for the 1st and 2nd sessions, and repeated in the retest. An instrumented hang board, with adjustable hold depths and 2D strain gauge sensors, captured applied force (N), time-to-exhaustion (TTE), and total work (TW).
RESULTS:
The average vertical force and TTE for both sessions was 320±0.1 N - 24.5±2.1 s for 10 mm, 326±0.6 N – 55.5±2.2 s for 15 mm, 377±1.6 N – 109.7±0.05 s for 20 mm, and 331±0.5 N - 158±16.9 s for 30 mm. Interclass Correlation Coefficient (ICC average [95% CI]) showed good to excellent consistency for all depths across sessions (10 mm, 15 mm, 20 mm and 30 mm, considering force (0.92[0.80-0.97], 0.99[0.99-0.99], 0.98[0.97-0.99], 0.99[0.98-0.99], respectively), TTE (0.77[0.41-0.91], 0.93[0.84-0.97], 0.92[0.80-0.97], 0.91[0.76- 0.96], respectively), and TW (0.81[0.40-0.94], 0.94[0.82-0.9], 0.90[0.70-0.96], 0.91[0.74-0.97], respectively).
CONCLUSION:
These results show a potential of this protocol to be used in future investigations to unveil the relationship between steady state work rate of the forearm muscles during isometric contractions and hold depths. This is an important initial step towards understanding the effects of different hold depths in climbers’ maximum work that the forearm muscles can maintain for an extended duration without fatigue (critical force [CF]) and characterizing the energy store component which is depleted above CP, first proposed by [3].
[1] https://doi.org/10.1016/j.jesf.2019.04.002
[2] https://doi.org/10.2478/hukin-2018-0057
[3] https://doi.org/10.1123/ijspp.2018-0809