Physiological and psychological contributions to on-sight rock climbing, and the haemodynamic responses to sustained and intermittent contractions

Abstract

Rock climbing is a multi-dimensional sport encompassing physiological, psychological, bio-mechanical and skill components. Interpretation of data in current investigations is limited by the lack of knowledge regarding the extent of the potential interaction of pre-climb anxieties with the physiological responses during an ascent. This thesis attempts to delineate the psychological and physiological contributions of on-sight top rope and lead climbing in multiple ability groups of rock climbers. Furthermore, the thesis goes on to gain an understanding of the de-oxygenation and re-oxygenation profiles in two forearm flexors during sustained and intermittent contractions-to-failure, as well as during the subsequent recovery period.

In study one, intermediate, advanced and elite rock climbers were asked to on-sight a route at the top of their respective best self-reported on-sight grade. There were no ability group or ascent style differences for any pre-climb measures of anxiety. However, elite rock climbers had significantly higher oxygen consumption, heart rate (HR) and cortisol (physiological component) responses compared to lower ability groups. Furthermore, the elite climbers spent a significantly greater percentage of their static time resting during the ascent compared to all lower ability groups. As there appears to be no differences in the anxiety based interaction with the physiological response, study one suggests that ability group and ascent style differences may be attributed mainly to the changes in the physical demands of the route. Furthermore, it would appear the higher level rock climbers may have a greater reliance on the aerobic metabolism during an on-sight ascent.

Study two investigated the haemodynamic responses to sustained and intermittent handgrip contractions which are seen during rock climbing ascents. Intermediate, advanced and elite climbers as well as a control group were asked to perform sustained and intermittent contractions (10s) at 40% of maximal volitional capacity until exhaustion. Oxygen saturation, blood flow (BF) and HR were measured pre, during and post contractions. Elite and advanced climbers were able to de-oxygenate both the flexor digitorum profundus and the flexor carpi radialis significantly more than the intermediate climbers, and the control group. During the intermittent test to failure, relative re-oxygenation during the rest period (3s) (re-oxygenation which takes into account the amount of de-oxygenation during the previous contraction), may be an important determinant of the force time integral. During the intermittent test, the increase in Δ BF, release HR and Δ HR during the rest periods suggest that vessel occlusion in elite and advanced rock climbers may not be as prominant as previously speculated upon. Furthermore, elite rock climbers appear to have a significantly faster time to half recovery after both sustained and intermittent contractions-to-failure.

In conclusion, it would appear that the psychological responses assessed pre on-sight rock climbing may not be different between ability groups or ascent styles. Instead, ability group differences may be due to physiological adaptations caused in part by the significantly greater amount of training. Furthermore, elite rock climbers appear to be able to de-oxygenate and re-oxygenate faster and to a greater extent than lower ability level climbers due to an increased Δ BF and Δ HR during intermittent rest periods, as well as post-exercise. Further investigation focusing on aerobic/anaerobic contribution, determination of capillary density and muscle fiber type would aid in gaining a greater understanding of rock climbing performance.