The chemistry-led quest to create the world’s best super chalk blends for climbers and weight lifters
Remember the sidewalk chalk you used to play with as a kid? Well, that’s not the stuff pro rock climber Sierra Blair-Coyle covers her hands with before scaling a difficult route.
Performance chalk—crucial for climbing, CrossFit, weightlifting, gymnastics, and bouldering—is a whole different beast that’s proven (and scientifically-modified) to give athletes a better grip, increase friction, stop sweat, and kill bacteria.
Manufactured from a solid, white inorganic mineral called magnesium carbonate, performance chalk contains compounds that are exceptionally good at absorbing the sweat from your hands and keeping your palms from slipping on the rock.
There's a reason you can't simply swap magnesium carbonate for cheaper blackboard or sidewalk chalk. "Magnesium carbonate is insoluble in water, so it doesn't dissolve,” says chemistry expert and Rice University Professor of Materials Science Andrew R. Barron. “But while calcium carbonate—or old-fashioned, traditional chalk—absorbs moisture, it also dissolves in water.” So if you’re lifting weights with sidewalk chalk on your hands, it’ll just run right off as soon as you start sweating. Not so with the high-end stuff.
But magnesium carbonate comes with its own set of problems. According to Blair-Coyle, extreme dryness and excess sweat are the most serious issues for climbers. "I've tried a lot of different types of chalk and...they’d either dry out my hands, or my skin, wouldn't last as long when I was climbing, or didn't give me the friction I needed on a hold," she says.
So scientists and athletes have turned to new additives like limestone, essential oils, and drying agents to make "super chalk" blends for weight lifters and climbers. The next time you're chalking up before a strength training session or climbing practice, remember—not all chalk is created equal. Here are five of our favorites.
SUNRISE Chalk Blend
SUNRISE Chalk blend includes premium-grade magnesium carbonate, plus the “perfect” drying agent (a trade secret) that provides max sweat absorption and friction. The blend comes in a powdered fine grind, chunk or nugget form, and block form.
SUNRISE crush chalk
It contains 100-percent natural fine-grained and chunk magnesium carbonate, no drying agents or chemicals added. The pro climber swears by its durability and drying properties.