From: CrossFit Journal
BY LON KILGORE
Reviewed: Bacon NT, Ryan GA, Wingo JE, et al. Effect of magnesium carbonate use on repeated open-handed and pinch grip weight-assisted pull-ups. International Journal of Exercise Science 11(4): 479-492, 2018. Available here.
Gyms have a love-hate relationship with chalk.
Trainees love to use it, but the people responsible for cleaning gyms hate it because a widespread dusting of white powder extends well beyond lifting areas even if a concerted effort is made to restrict its use to a portion of the gym. It takes time to sweep and mop it up.
Everyone “knows” chalk is used to improve their grip on barbells, pull-up bars and other equipment. Go to any CrossFit, weightlifting-friendly or powerlifting-friendly gym and you’ll see people applying chalk (aka, magnesium carbonate, magnesium alba, gym chalk and gymnastics chalk, among others) to their hands, thighs, shoulders, T-shirts at the front of the shoulders or the back, the backside of their shorts and so on. Frequently, liberalness of application approaches a bath of chalk.
We’ve all been told that using chalk increases the friction between bar and hand, thus making the grip more secure and slippage less likely. But do we actually know chalk does what we think it does? No research has been performed on chalk use and gripping a barbell. Actually, fewer than a dozen papers address chalk, and the majority relate to rock climbing. A new paper by Bacon and co-workers is also focused on rock climbing, but it does examine a very common gym exercise: the pull-up.
The paper itself was very small scale, with only nine subjects. Its authors conjectured that chalk use would increase the number of pull-ups completed using an assisted-pull-up machine loaded to 50 percent of body weight. Two conditions were tested: fingers wrapped over the top of climbing holds and fingers pinched on the climbing hold from below. A limitation: The use of climbing holds rather than a pull-up bar does restrict our ability to apply the findings to the common gym exercise, but a nugget of utility can be found.
As we are biased to believe, researchers discovered chalk use appeared to allow the completion of more repetitions in both conditions:
- Subjects completed roughly 23 repetitions with the top grip and chalk versus about 19 repetitions without chalk.
- Subjects completed roughly 14 repetitions with the pinch grip and chalk versus about 9 repetitions without chalk.
Kudos go to the lead author, an undergraduate student, for investigating an interesting but under-researched topic.
If we cautiously generalize the findings to lifting, chalk use appears to be beneficial for higher-repetition lifting. The singular focus on repetitions, however, limits these experimental findings—along with those in the earlier work of Kilgas (1)—in that they explored the effects of chalk on endurance-based grip. As such, the findings might not extrapolate to high-force-related grip performance on lifts such as heavy deadlifts, cleans and snatches.
We can find a bit of direction on single-effort lifts from a relatively carefully controlled comparison of the effects of chalk versus no chalk on bar grip (2). The study examined slide control of a vertically held steel bar, and the resulting data showed that chalk improved the ability of subjects to apply enough grip force to limit downward slippage of the bar. Although a barbell is held horizontally, this paper does provide evidence that chalk can be beneficial to grip performance on single efforts.
But not every one of the few papers on the topic demonstrated positive results.
Chalk is widely accepted as a means to reduce the incidence of blisters and calluses. This might or might not be supported with research. In one of the few papers available, chalk use appeared to increase palm-surface temperature on gymnasts using the parallel bars, with the researchers concluding that blister formation would be reduced if the athletes did not use chalk (3). It should be noted that this is conjecture only as the paper did not actually assess blister formation.
If we go back to an even earlier study, Li and associates examined various substances’ effects on coefficient of friction of the hand against various stone surfaces (4). While chalking produced negative effects, the researchers’ data suggested application of chalk, then removal of chalk, would enhance coefficient of friction and improve grip. Caked chalk on the palm essentially acts as a lubricant, with the chalk particles moving easily over themselves and the skin. By first applying chalk to absorb moisture and oils from the hand, then removing the chalk, friction between stone (possibly steel) and skin is optimized. This does provide some evidence to support the annoying habit of those who encase their hands in ludicrous amounts of chalk, then clap them hard, thus removing most of what was applied and making a mess.
Something few people consider is that gym chalk use can increase the particulate matter in the air inside a gym by about 2,400 percent over that seen outdoors, and about 14 percent of particulates inhaled when in the gym are retained in the alveoli (5). Although gym chalk does not have an established toxicity and has not been researched in this respect, it would be prudent to reduce chalk accumulations by regular cleaning and by advising trainees to use only enough to dry the hands. The action of chalking should not be an excuse to take frequent breaks, chalk should not be caked thickly, and chalk should not be wasted by creating plumes of airborne particles through theatrical chalking that increases respiratory risk.
- Kilgas MA, Drum SN, Jensen RL, Phillips KC, Watts PB. The effect of magnesium carbonate (chalk) on geometric entropy, force, and electromyography during rock climbing. Journal of Applied Biomechanics 32: 553-557, 2016.
- Yamaguchi T and Hokkirigawa K. Magnesium carbonate and rosin powders stabilize sliding motion between rubber-gloved human hand and grasped cylindrical bar. Journal of Advanced Mechanical Design, Systems and Manufacturing 9(3): 1-10, 2015.
- Pusnik I and Cuk I. Thermal imaging of hands during simple gymnastics elements on the wooden bar with and without the use of magnesium carbonate. Science of Gymnastics Journal 6(1): 67-72, 2014.
- Li FX, Margetts S, Fowler I. Use of ‘chalk’ in rock climbing: sine qua non or myth? Journal of Sports Science 19: 427-32, 2001.
- Alves C, Calvo AI, Marques L, Castro A, Nunes T, Coz E, Fraile R. Particulate matter in the indoor and outdoor air of a gymnasium and a fronton. Environmental Science and Pollution Research 21(21): 12,390-402, 2014.
About the Author: Professor Lon Kilgore is a longtime contributor to the CrossFit Journal and the fitness industry in general. He might be best known for his work with Mark Rippetoe as concept originator, co-author, illustrator, and book designer for “Starting Strength” and “Practical Programming” (first and second editions). He also co-created the Basic Barbell Training and Exercise Science specialty seminars offered through CrossFit in the mid-2000s. After a 20-year professorial career in higher academia, he currently creates and delivers vocational-education courses through the Kilgore Academy and works as a writer and illustrator.
Cover image: Matt Palmer/Koda CrossFit Norman