Do you struggle to remember your mental shopping list or forget people’s names right after you’re introduced? A new study reveals a “handy” trick that can help—and all you need to be able to do is make a fist.

Background: Previous research has shown that when a person clenches his or her right fist, the frontal lobe on the left side of the brain shows increased activity. Similarly, clenching the left fist activates the right side of the brain. There is a lot we don’t know about how the way the brain works, but some experts believe that the left frontal lobe is important to encoding (creating) memories, while the right frontal lobe is associated with retrieving (recalling) memories. So if hand clenching increases activity in different parts of the brain, researchers theorized, then clenching the right hand would activate the left side of the brain, where memories are encoded…and clenching the left hand would activate the right side of the brain, where memories are recalled.

To test the concept: 51 right-handed people were recruited to participate in the study. (Left-handed people already have superior memories, according to research, so they weren’t included in this study.) All of the participants were shown a series of 36 random words, with each word being displayed for five seconds…then later, they were asked to write down as many of the words as they could. Prior to reading and recalling the words, however, the participants were divided into five groups. In one group, each member was told to tightly squeeze a small rubber ball (to ensure a fist-clenching action) in his right hand for 90 seconds before seeing the words, then squeeze the ball in his left hand for 90 seconds before trying to recall the words. A second group did the opposite (left before reading, right before recalling). Two other groups used their right hands both times…or used their left hands both times. The fifth group didn’t clench their fists at all—they simply cupped the ball gently in both hands.

Results: People who were able to recall the most words correctly were those who had squeezed with their right hands before trying to memorize the words and with their left hands before trying to recall the words. These people remembered almost 15% more words, on average, than the second-best performing group, which was the group that did not clench their fists at all. You don’t consider a 15% improvement in memory such a big deal? Well, think of it in test-scoring terms—it could be the difference between an A and a C. Curiously, the three groups that did the “wrong” kind of clenching did even worse than the no-clenching group.

Give it a whirl: You don’t need a ball. If you want to remember things better, simply clench your right hand for a minute and a half before you try to commit something to memory—a shopping list, a to-do list, a train schedule or the spot at the mall where you parked your car. Then clench your left hand for a minute and a half before you try to recall that list, train schedule or parking spot number.

Just remember to clench right to learn, left to recall (ironically, the “R” and the “L” mnemonics are opposite). Careful—if you swap those, you could wind up recalling less than you would have if you had done no clenching at all.