New research supports climbing chalk.
We've known since we began climbing that ALL climbers need chalk. Some can get away without using it on some rock types (sandstone) or in the gym where holds can be extra grippy when new... But MOST of use use it because we feel like it really helps... But does it?!
Climbers chalk (Magnesium Carbonate) is the main product on the market. Used as liquid chalk and as really does help us to apply more load and to slide less while doing so. Original research in 2012 told us that there was no benefit to climbing chalk. Used on a variety of climbing surfaces (slate, granite, sandstone), the research did not point to any real data to back up our claims. They concluded that climbers chalk had no physical benefit and went on to say that its utility may only have been of 'psychological benefit.'
In 2016 in the Journal of Applied Mechanics, researchers Klingas et al. set out again to test this exact question again using apparatuses that were slightly more climbing specific. They tested 19 'experienced' rock climbers wondering about the scientific questions of geometric entropy, force, and electromyography. During this study, investigators assessed chalk’s coefficient of friction while participants were statically hanging from a hang board. Participants hanged until failure while force plates attached to the hang board measured loads. The hand was in essence laid flat (pronation) on a flat surface.
Although there were no differences in the coefficient of friction (P = .748), geometric entropy (P = .359), the ratio of the vertical forces between the hands and feet (P = .570), or muscular activity (P = .968), participants were able to hang longer after the use of chalk 62.9 ± 36.7 s and 49.3 ± 25.2 s (P = .046). So...to learn from this research, if it's not friction that makes us hang longer, what is it?! Or IS it friction but we are just not able to calculate it correctly?
Another study (2018) by Bacon, et al was published in the International Journal of Exercise Science. Titled "Effect of Magnesium Carbonate Use on Repeated Open-Handed and Pinch Grip Weight-Assisted Pull-Ups" studied this correlation trying to be as specific as possible to replicate outdoor usage patterns. Using climbing specific holds (pinch vs open hand) anchored to a pull-up bar using a physiologically similar body position to climbing (as compared to internally rotated as in the 2016 study). (see link for images), Similar variables were measured using a small trial of only 6 recreational climbers. They also used intraclass correlations for test-retest of the open-handed (R = 0.99) and pinch grip (R = 0.96). Weight assisted pull-ups evidenced reliable values.
When compared to the non-chalked trials, chalk improved both openhanded (mean = 22.8 ± 4.53 vs. mean no chalk = 19.7 ± 4.39 reps; p = 0.006,) and pinch grip (mean = 14.4 ± 4.47 vs. mean no chalk = 9.1 ± 4.83 reps; p = 0.007) in a weight assisted pull up. Intraclass correlations indicated a reliable measurement, while chalk improved performance for both open-handed and pinch grip weight assisted pull-up when compared to no chalk trials. They also found that the climbers had much harder time with the pinch grip setup and were unable to use the hold as much as they were for the open hand position on the machine. It is interesting to mention that before and after this trial, the grip strength on these 'recreational climbers' was the same. This means that they were actually trained for climbing and the researchers state this in their research paper also pointing out that the tested subjects showed a enhanced vasodilatory capacity.
Possible future questions in regards to chalk research:
1. If we change temperature and/or humidity, at what level does chalk work best? My favorite researcher Laurent Vigouroux (Amca, et al) wrote in the Journal of Sports Biomechanics that their team could not find a difference in their 2012 research. However they also noted that suggested that additional parameters should be considered in order to understand the effects of climate on finger friction in rock climbing.
2. For those who perspire more than others (terror, excitement, etc), how does chalk compare? And liquid chalk at that? (Perhaps we could scare climbers, or make them watch an intense video and then compare the amount of slip vs. dry conditions. This would be impossible to do as a double blind study).
3. What preparation technique is best to assist the coefficient of friction, should we wash with a certain soap, use anhydrous solution, or clean our hands with rubbing alcohol?
Also, once we set this baseline, we can now ask, does one texture or style of chalk work better than another? Research says keep it thin and don't use too much.
As a group we are THANKFUL for all the researchers who are spending their time asking these questions. It's NOT all in our head and we'd love to have as much information as we can especially when we are attempting something that has a fall risk or an element of danger to it. Keep healthy and climb on!!
2012. Li FX, Margetts S, Fowler I. Use of ‘chalk’ in rock climbing: sine qua non or myth? J Sports Sci. 2001;19:427–32.
2016. Kilgas MA, et. al The effect of magnesium carbonate (chalk) on geometric entropy, force, and electromyography during rock climbing. J Appl Biomech. 2016;32:553–557.
2018. Bacon N.T. et al. Effect of Magnesium Carbonate Use on Repeated Open-Handed and Pinch Grip Weight-Assisted Pull-Ups Int J Exerc Sci.; 11(4): 479–492.
2012. Amca AF, Vigouroux L, Aritan S, Berton E. The effect of chalk on the finger-hold friction coefficient in rock climbing. Sports Biomech. 2012;11:473–79.