Following 24-h sleep deprivation, creatine supplementation had a positive effect on mood state and tasks that place a heavy stress on the prefrontal cortex.

Rock climbing is a popular adventure sport with an increasing research base. Early studies in the field did not make comparisons of ascents using different styles of climbing. More recently, differences in the physiological responses for an onsight lead climb and subsequent lead climb have been reported. The purpose of the present study was to examine the effect of style of climb (lead climb or top rope climb) on the physiological and psychological responses to rock climbing. Nine intermediate climbers volunteered for, and completed, two randomly assigned climbing trials and a maximum oxygen uptake (VO 2max ) test on a separate occasion. The climbers ascended the same 6a (sport grade) climb for both trials. Before climbing, heart rate, perception of anxiety (Revised Competitive State Anxiety Inventory-2), and blood lactate concentration were measured. Climb time, heart rate, VO 2 , lactate concentrations, and task load (National Aeronautics and Space Administration Task Load Index) in response to each trial were also recorded. Results indicated significant differences (PB0.05) between the trials for climb time, blood lactate concentration immediately after and 15 min after climbing, and heart rate 1 min after climbing. During lead and top rope climbing, mean VO 2 and represented 44% and 42% of treadmill VO 2max and mean heart rate represented 81% and 77% of maximum heart rate, respectively. There were no significant differences in feelings of anxiety before either climb, although climbers reported the lead climb to be physically and mentally more demanding, requiring more effort and resulting in greater frustration (P B0.05) than the top rope climb. Our results indicate that the physiological and psychological responses of intermediate climbers are different for a lead climb and top rope climb.

Objectives: To examine how different safety rope protocols impact on subjective anxiety and self-confidence levels and plasma cortisol concentrations and the relationship between subjective states and cortisol during rock climbing. Methods: Participants (n = 12) were tested in three climbing conditions that were designed to invoke low, moderate and high physical and mental stress. Plasma cortisol concentrations were collected before and after climbing and participants reported subjective anxiety and self-confidence states for each climb.Results: Repeated measures analysis of variance showed significant differences between conditions for somatic anxiety (F 2, 22 = 7.74, p = 0.009), self-confidence (F 2, 22 = 9.52, p = 0.001) and change in plasma cortisol concentration (F 2, 22 = 3.71, p = 0.041). Preplanned polynomial comparisons showed that these were linear effects; somatic anxiety was higher in the higher stress conditions whilst self-confidence was lower. Plasma cortisol concentration change was also linear. Regression analyses showed cubic relationships between plasma cortisol concentration and cognitive anxiety (R 2 = 0.452), self-confidence (R 2 = 0.281) and somatic anxiety (R 2 = 0.268). Conclusions: There is a relationship between plasma cortisol concentration and subjective anxiety and selfconfidence states during rock climbing. Changes in the way the safety rope is organised can impact on anxiety, cortisol concentration and self-confidence during rock climbing.

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