Can a natural capsule help divers hold their breath longer?

This study is testing whether a supplement called beta caryophyllene, which comes from plants, can help elite freedivers improve their ability to hold their breath underwater. Fifteen experienced divers will take either the supplement or a placebo (a dummy pill) and then perform a single, maximum breath-hold test. Researchers will measure how long they can hold their breath and check some basic body signals to see if the supplement makes a difference.