While other fans linger in the parking lot before a game, I’ve always liked heading into the stadium early to watch the players warm-up. To see them taking batting practice, practicing shots or passing the ball around makes them seem more accessible or mortal to me before the chaos of competition starts and I see how good they really are.

These pre-game preparations are certainly important for warming up the arms and legs, getting the heart rate up and loosening up muscles. But maybe more importantly, this skill repetition also gets the brain ready for the hundreds of actions it will need to perform soon after. The hours previously spent in practice honing the speed and accuracy of pitches, shots, passes, catches and hits has grown a database of motor programs that an athlete can call on during a game. Recent research has shown that all of this practice enables players to consolidate or “chunk” these skills into packages that are retrieved faster if the brain is prepped ahead of time.

Waking up these stored motor programs during warm-ups helps in both planned skill movements (like a quarterback working through his set of standard passes or a basketball player taking pre-game shots from around the court) and in unplanned, reactive skills (like a goalkeeper working through a progression of shots against). When the game begins, reaction times become critical to respond to the changing needs of the moment. A sub-second advantage over the opponent can be the deciding difference.

Researchers at Johns Hopkins University (JHU) have been studying how we acquire and adapt our motor skill inventory to get to the desired goal of “automaticity” or being able to execute skills without consciously thinking about them. Their primary, non-sports-related motivation is to help recovering stroke patients regain their functional lives by understanding and retraining those patients’ brains to relearn basic movements. Luckily for us, much of their work also translates to sports with the heavy emphasis on complex actions.

In our recent book, The Playmaker’s Advantage, we highlighted the research of Dr. John Krakauer in his BLAM Lab at JHU. He leads a multidisciplinary team of specialists designing video-game tools to help patients reconnect brain and body, often with new paths circumventing the traditional but damaged connections. As we learned from Dr. Krakauer, all physical movement starts with a command from the brain. “The point is that some people even said that thought is basically movement, planning without the movement,” said Krakauer. “And so, from an evolutionary standpoint, you can imagine that if we understood motor planning and simulation without the movement, very likely those planning processes were co-opted for higher-level thought.”

Several previous experiments from Krakauer’s lab as well as the Human Brain Physiology and Stimulation lab of Dr. Pablo Celnik, also at JHU, have found that our reaction time to a stimulus improves (decreases) when we practice the desired movement ahead of time. For example, if we are asked to move a computer mouse cursor to a target on the screen as soon as it appears, we get faster at it to the extent we’re allowed to practice the movement ahead of time. That makes logical sense as we’ve always heard that practice makes perfect and a rehearsed task will help us master it.

But why does practice reduce reaction time? What exactly is happening in our brains to help us become not only quicker but more accurate in our movements? By combining both the perceptual and motor functions into the total reaction time, we need to tease apart whether practice improves the sensing components of seeing the target and sending a signal to a motor command or if the advantage comes on the back end of a motor command being pre-loaded into working memory so that the access time is shorter after the eyes have given the green light.

Dr. Celnik, along with fellow researchers Adrian Heath, Daniel Lopez, and Firas Mawase, knew that previous experiments with transcranial magnetic stimulation (TMS), used to trigger and record brain responses, showed that if volunteers practiced a movement prior to the stimulation, they would tend to reproduce a similar movement after a TMS stimulation. With no chance to visually anticipate a needed movement, the test subjects showed that shorter reaction times after practice must be related to something else.

"These studies suggest that something other than anticipation might be happening with repetition," said Dr. Heath.

So, the researchers designed a new experiment that asked a group of 36 adult volunteers to point a mouse cursor at a target on a screen as soon as it appeared. Their reaction times were recorded as a baseline. Then, the volunteers were asked to practice a single mouse movement, up and to the right, hundreds of times in a row. After this mass repetition, they were tested again with the target appearing in random locations. Whenever the target was in the upper right location, their reaction time was reduced significantly from the original 215 millisecond baseline.

"The benefit you get is 20 to 30 milliseconds," said Dr. Celnik. "It sounds small, but when you're looking at performance that can make a difference in sports and other areas that require quick motor movements, that time increment might mean the divide between a winner and a loser."

But their goal was to eliminate anticipation, similar to the TMS studies, as a possible advantage. So, they conducted a second experiment with the same set-up except that the volunteers were asked to make their hand movements on every fourth beat of a metronome. They reasoned that if visual anticipation was causing quicker hand movements, the restriction on the reaction timing would nullify it.

"The subjects did have preferred directions for moving their hands when they had to guess, but it was mostly directions comfortable for right-handed people," said Dr. Mawase. "They either chose up and to the right or down and to the left, rather than in the direction they'd practiced."

The research was published in Cell Reports.

From these results, the new thinking is that practice helps with the backend of movement, the retrieval of stored motor programs prior to the trigger to help react quicker.

“Our study suggests the existence of a separate mechanism whereby recent movement history might influence motor performance—in this case through facilitating more rapid response preparation, that is, how quickly we generate a subsequent movement in response to a sensory stimulus,” concluded the research team.

Hours of deliberate practice teach the brain how to make a skilled sports movement. At gametime, it seems that priming the memory to pull up those known motor programs helps an athlete prepare for the upcoming competition where milliseconds make a difference. The next time you’re headed for a game, get there early and watch those players’ brain wake up and become activated.