What Does Gym Chalk Do?One of the properties of a dry lubricant is the easy movement of particles between surfaces. If a dry material easily breaks down under sliding pressure, it facilitates movement and reduces the friction between two surfaces. This tendency, known as low shear strength, is one of the properties of talc. While gym chalk does not have the low shear strength of talc, it does put moving particles between your hands and the barbell or gripping surface. At least one study, focused on climbers, concluded that magnesium carbonate creates "a slippery granular layer" between the hands and a gripping surface. So what about chalk makes it useful for lifting?
What Does Gym Chalk Do?
The popularity of the new sport of weightlifting in Quebec City also brought comedy events. One of these events occurred when the new club began using sodium bicarbonate, a kind of white chalk athletes use to remove sweat in their hands during training or tournaments. The Hercule Gym was located opposite the Pelletier drug store; Maurice went to inquire on the possibility to get a small block. As it is usually used to soothe the stomach pains, the pharmacist sold him one block, which he sold very infrequently. However, the pharmacist became very upset when Maurice repeated his trick for several consecutive weeks. The pharmacist finished by recommending strongly to Maurice to see a doctor at the earliest, saying the problem was becoming very serious! Maurice explained to the pharmacist how the athletes were using of the sodium bicarbonate, which reassured him.
-from Yvon Chouinard, “Origins of Canadian Weightlifting” (available at https://cdnmastersweightlifting.org/documents/history/Origins%20of%20Canadian%20weightlifting.pdf)
A brief search into the history of chalk in barbell training reveals… not much, other than it seems to have been a staple of black iron gyms since at least the 1950s and possibly long before that. The earliest accounts we found mentioning its use in barbell training (usually for the sport of weightlifting) typically date to the 1950s and chalk seems to be ubiquitous after that.
Chalk, as the story above mentions, isn’t chalk in the classroom blackboard sense. It is a chemical compound (though it is most commonly a different compound than that mentioned above): magnesium carbonate (MgCO3).
In the 1950s, climber John Gill brought magnesium carbonate from gymnastics to climbing. John Gill would become a climbing legend and the father of modern bouldering. He was a gymnast and saw climbing as having the possibility to share the same aesthetic movement as gymnastics. His approaches to climbing and his importation of gymnastics chalk to the sport both spread internationally.
The use of chalk for lifting likely shares its origins in gymnastics, since modern gymnastics far predates modern barbell training. Gymnastics, as a concept of physical development, movement, and aesthetics, dates back to ancient Greece. Modern sport-gymnastics began in Germany in the 1800s and has been taught in United States universities since about the time of the civil war. Gymnastics was an event in the first modern Olympic Games in 1896, and it looked very similar to the modern sport of gymnastics as we know it. Weightlifting, in contrast, retained some of the flamboyance of its circus strongman roots even as an Olympic event. The 1896 weightlifting events involved style points and freestyle lifting, no weight classes, and no recognizable rules to current fans of the sport. It wasn’t until 1920 that the modern version of Olympic Weightlifting as a sport started to take shape and 1928 when it became (more or less) the sport we know.
However it was first discovered that chalk could keep hands dry without making them slick, it seems natural that the use of chalk would drift from one sport to another, coating barbells as readily as gymnastic apparatuses. Let’s look at how a powder can improve the safety and efficacy of training, and why it is worth the extra chalk dust in the air and the extra brushing you give your barbells.
Grip and Friction
Chalk improves contact with the bar. In each of the main barbell lifts, we want a stable, unmoving connection between our hands and the bar. For the deadlift, specifically, we want something that will help us hold onto the bar without artificially augmenting our grip strength. Presumably, chalk helps by drying our hands and increasing friction between our hands and the bar.
But does chalk improve friction or does it simply dry your hands? And, if it only dries your hands can you manage without chalk (there are other ways to keep your hands dry)?
Some studies have looked at the effects of chalk in gymnastics, climbing, and gripping situations. One used thermal imaging to measure the relative hand temperature during a basic gymnastics movement on the parallel bars with and without chalk. Gymnasts use chalk to decrease moisture and improve their grip. The researchers wanted to assess the danger of blisters without chalk as part of an overall analysis of the costs and benefits of chalk use, the costs being messiness, air quality, and cost of supplying chalk. The paper did not assess blister formation, but instead addressed the issue of palm temperature, positing that higher temperature of the palm would lend itself more readily to blister formation. The researchers found that palm temperature increased with the use of chalk, concluding that chalk did not protect against blisters. If we extrapolate just from measurements of palm temperatures, this might suggest that chalk increases the friction between the hand and a gripping surface. This, however, was not studied or commented on by the researchers.
The issue of friction is a little bit more complicated. Friction is a crucial component of grip force and grip strength. Friction not only makes the translations of two surfaces less likely but also is picked up by your sense of touch. Your central nervous system regulates grip force, and your ability to optimize grip force in different situations depends in part on the amount of friction you can sense against your skin. Studies that measure grip force tend to find what you would expect: clean, dry hands grip better than sweaty, dirty, or greasy hands, and “friction between the skin and a grasped object is a powerful determinant of the grip force used to hold the object against gravity.” So, if an increase in friction leads to a better grip, does that mean that the improved grip you experience when using chalk in barbell training is due to improved friction with the barbell?
Not necessarily. One of the properties of a dry lubricant is the easy movement of particles between surfaces. If a dry material easily breaks down under sliding pressure, it facilitates movement and reduces the friction between two surfaces. This tendency, known as low shear strength, is one of the properties of talc. Talc used to be the main ingredient in baby powders due to its drying and lubrication properties. While magnesium carbonate does not have the low shear strength of talc, it does put moving particles between your hands and the barbell or gripping surface. At least one study, focused on climbers, concluded that magnesium carbonate creates “a slippery granular layer” between the hands and a gripping surface. (F.-X. Li, S. Margetts & I. Fowler (2001): Use of ‘chalk’ in rock climbing: sine qua non or myth?, Journal of Sports Sciences, 19:6, 427-432.) That paper performed its study in a laboratory used artificial sliding surfaces. A later study hypothesized that “the granular layer effect hypothesized by Li et al. (2001) is probably canceled out by the force intensities encountered during rock climbing,” meaning that in real-life, non-lab settings chalk seemed to benefit the climbers’ grips. Arif Mithat Amca, Laurent Vigouroux, Serdar Aritan & Eric Berton (2012) The effect of chalk on the finger–hold friction coefficient in rock climbing, Sports Biomechanics, 11:4, 473-479, DOI: 10.1080/14763141.2012.724700. Some climbers have taken the first study to suggest that the only benefit of chalk is to keep your hands dry and that climbers should find other ways to dry their hands, using towels or even dirt from the surrounding rock face. The takeaway is that magnesium carbonate has some general lubrication properties, but some factors cancel those properties out.
In barbell training, there are two significant factors that mitigate any lubricating properties of magnesium carbonate. The first is the nature of your grip. We are mainly concerned with holding onto a deadlift as the test of the efficacy of chalk. In the deadlift, the grip is only partially dependant on friction. The weight of the bar is pulling the bar to slide out of your hands, but it is also rolling out of your hands, trying to extend your fingers and overcome your gripping muscles. This is why you feel much more secure holding the bar with a mixed grip, with one hand supinated, where the bar is rolling into both hands. The mixed grip takes one of the dimensions of grip strength out of the situation. But we still have to contend with friction. While it hasn’t been studied the same conclusion of Mithat et al, if applicable, may apply to barbell training. The force intensities of your grip in barbell training are likely to negate the powder’s sliding particles between your fingers. While magnesium has a low shear strength, it is not classified as a dry lubricant.
Second, the texture of the barbell may also help negate the potential lubricity of the power. A smooth and flat surface would provide more contact area between your hand and the lubricating particles of the chalk, but the texture of the knurling of the barbell reduces that surface contact area negating at least some of its lubricating properties. (See Cadoret and Smith, “Friction, Not Texture, Dictates Grip Forces Used During Object Manipulation,” Journal of Neurophysiology, Vol. 75 No. 5 (1996).) Whatever the reason, we do not experience a lubrication effect when using chalk.
That is, in part, because chalk is excellent at keeping your hands dry for a heavy work set. Sure you could try drying your hands without chalk before stepping up to the bar, but if you are deadlifting heavy enough for it to matter, you will be sweating. Chalk makes a difference. If you aren’t using it already, here are a few tips:
- Don’t break the chalk: Lifting chalk comes in blocks and should stay that way as long as possible, this allows you to apply chalk to your hands in reasonable amounts, in the right places, without making a mess.
- Ask forgiveness, not permission: If your gym doesn’t provide chalk, you can bring your own. Climbing bags make for great chalk carriers.
- Liquid chalk in a pinch: Liquid chalk, like Liquid Grip sold at Rogue Fitness, isn’t as good as a big block of magnesium carbonate, but it will get the job done. It has the added benefit of being discreet and less prone to messiness than regular chalk.
- Don’t be excessive: While chalk is beneficial for your grip, you don’t need to bathe in it. Nor do you need to clap, just to see that white cloud before you lift. Apply it, rub your hands, and lift. Simple.
There’s a reason chalk has such a long history with lifting. It works. It’s not sticky like rosin. It improves friction by keeping your hands dry long enough to finish your set, and it doesn’t break down and cause the bar to slip or slide in your grip. This makes it both useful and necessary for safe lifting and effective training.
 One of the arguments against lifting chalk is that it affects the air quality of the gym. While nothing has shown magnesium carbonate to be toxic—it’s been used as a food additive for over a century—talc is considered toxic if inhaled. For that reason, most baby powders today are made with cornstarch instead of talc.
 “There are only a few muscles in your hand and forearm that contribute to grip strength. The Flexor Digitorum Superficialis and Flexor Digitorum Profundus flex or “curl” your fingers at the proximal/medial and distal phalanges respectively (“digitorum” refers to your digits or fingers). The muscles that flex your thumb are the Flexor Pollicis Brevis and the Flexor Pollicius Pongus (“pollicis” refers to the thumb). These muscles are extrinsic to the hand, meaning their muscle bellies are located on your forearm. There are some muscles intrinsic to your hand that contribute to grip strength, but they are smaller and dedicated more to fine motor functions rather than blunt grip force. Since we are more concerned with grip strength function than with training individual muscles, the real question is how do we make the coordinated force production of these muscles stronger.” (from Training Your Grip)