Forearm blood flow and vascular conductance improve after 18 weeks of bouldering training in novice climbers.

BACKGROUND

Indoor climbing can be associated with improvements in muscle strength and cardiorespiratory capacity. However, acute climbing sessions have shown to elicit an excessive hemodynamic response, and chronic vascular adaptations are still unknown. The aim of this study was to evaluate vascular adaptations and their association with grip strength and hangboard performance after an 18-week bouldering program in participants without prior climbing experience.

METHODS

Forearm blood flow (FBF) was measured with venous occlusion plethysmography. Muscle strength was assessed by handgrip dynamometry, muscle endurance by the dead-hang test, and body composition by air displacement plethysmography.

RESULTS

We enrolled 26 controls and 27 novice climbers. At baseline, there was no difference between controls and novice climbers regarding age, sex, body composition, FBF, muscle strength and endurance. Novice climbers showed greater delta improvement in left-hand [5.7 (IQR: -1.6-17.2) vs. -4.1 (IQR: -8.0-1.9) %; p = 0.001], right-hand grip strength [3.8 (IQR: -1.3-13.6) vs. -0.9 (IQR: -6.4-4.5) %; p = 0.011], and hangboard time [23.8 (IQR: 5.1-68.7) vs. 1.8 (IQR: -21.7-13.9) %; p = 0.005]. Novice climbers had better delta changes in FBF [34.0 (IQR: 2.8-54.5) vs. 0.1 (IQR: -23.1-23.6) %; p = 0.010] and forearm vascular conductance [26.5 (IQR: 6.7-66.7) vs. 0.3 (IQR: -23.1-20.2) %; p = 0.011]. A positive correlation was found between delta changes in hangboard time and forearm vascular conductance (r = 0.29; p = 0.041), along with left-hand grip strength (r = 0.28; p = 0.038).

CONCLUSION

In conclusion, an 18-week bouldering program improved handgrip strength, hangboard time and vascular function in participants without prior climbing experience, while gains in hangboard performance were associated with improvements in vascular function.