The effect of technique and ability on the VO₂–heart rate relationship in rock climbing

Previous studies have speculated that the disproportionate rise in heart rate for a given VO₂ may be due to anxiety, increased time spent in isometric contraction and the possible presence of the metaboreflex. The current study measured time spent in isometric contraction, rest time, pre-climb anxiety, heart rate and VO₂ responses in advanced (n = 11) and intermediate (n = 11) rock climbers performing at or near their maximum self-reported on-sight grade (19/22 Ewbank). Results showed a non-significant difference (p > 0.05) between groups for climb time, pre-climb heart rate and state anxiety. Throughout the majority of the climbs, it was observed that the intermediate group’s heart rate per VO₂ ratio was significantly greater (p < 0.05) than that seen in the advanced group. Advanced climbers spent a significantly greater period of time (p < 0.05) in an isometric position but interestingly spent a significantly greater period of time (p < 0.05) shaking out and actively resting the arms. It would appear that pre-climb anxiety played no part in the disproportionate rise in heart rate per VO₂. However, the significantly increased rest time (p < 0.05) and the ability to make tactical route decisions may have increased recovery forearm blood flow, reducing metabolites and the presence of the metaboreflex.