Arm position, but not laterality or climbing ability, modulates forearm oxygen recovery dynamics in rock climbers

Forearm muscle oxygen recovery has been identified as an important physiological correlate of climbing performance, yet it is typically assessed in positions that do not reflect the overhead demands of climbing. It remains unclear to what extent arm position and upper-limb laterality influence oxygen recovery dynamics across climbing ability levels. Therefore, this study examined the effects of upper-limb position and laterality on forearm oxygen recovery in climbers of different ability levels. Fifty-one male participants, including advanced-to-higher elite climbers ( n = 20), intermediate climbers ( n = 21), and non-climbing controls ( n = 10), completed bilateral arterial occlusion tests in two randomised conditions: supine (0° shoulder flexion) and elevated (180° shoulder flexion). Muscle oxygen saturation (StO₂) in the finger flexors was measured using near-infrared spectroscopy. StO₂ half-time of recovery (HTR) and recovery rate were calculated following occlusion release. Data were analysed using generalised linear mixed models. Upper-limb position was the only significant factor affecting oxygen recovery dynamics. Compared with the supine condition, arm elevation resulted in a 2.44-fold increase in StO₂ HTR and a ~ 61% reduction in StO₂ recovery rate (both p < .001). No significant effects of laterality, climbing ability, or their interactions with arm position were observed. These findings indicate that the influence of arm elevation was consistent across limbs and performance levels. Substantial inter-individual variability in response to arm elevation was also evident. Arm elevation markedly impairs forearm oxygen recovery dynamics, demonstrating that reoxygenation is highly sensitive to limb position. However, oxygen recovery dynamics assessed by arterial occlusion were not associated with climbing ability or limb dominance. While the protocol was not sensitive for distinguishing performance level, it may provide useful insight into position-dependent changes in forearm muscle oxygenation relevant to overhead activities.