Learning a new skill doesn’t depend so much on how much practice you do, but how you practice. The key is to subtly vary your training with changes that keep your brain learning. By changing up your routine, new research says, you can cut the time to acquire a new skill by half.

Acquiring new motor skills requires repetition, but iterative repetition is much more effective than just doing the same thing over and over. A new study from Johns Hopkins found that modifying practice sessions led participants to learn a new computer-based motor skill quicker than straight repetition. The results suggest that a process called reconsolidation is at work.

Reconsolidation is a process in which “existing memories are recalled and modified with new knowledge.” The new study, led by Johns Hopkins University professor Pablo Celnik, demonstrated that reconsolidation is also key to learning motor skills, a process about which little was previously known.

“What we found is if you practice a slightly modified version of a task you want to master,” said Celnik, “you actually learn more and faster than if you just keep practicing the exact same thing multiple times in a row.”

Eighty six volunteers were trained to manipulate a cursor on a computer screen by squeezing a small device. Three groups each trained for a 45-minute session. Then, six hours later, one group repeated the same exercise, while another group performed a modified version, with slightly different squeezing force required. Both these groups repeated the first task the next day, and a control group only did one session per day.

The control group did worst, roughly half as well as the group that simply repeated the training. The group that switched things up did best of all, performing almost twice as well as the repetitively trained group.

The trick to making this work is to make small variations in practice sessions, “akin to slightly adjusting the size or weight of a baseball bat, tennis racket or soccer ball in between practice sessions.” Bigger changes seem not to help.