Peter Brown (Make It Stick: The Science of Successful Learning) calls this the myth of massed practice. “Most of us believe that learning is better when you go at something with a singleminded purpose,” says Brown. “Faith in focused, repetitive practice of one thing at a time until we’ve got it nailed is pervasive among classroom teachers, athletes, corporate trainers, and students. Despite what our eyes tell us, this faith is misplaced.” The faith is misplaced because, in the short term, we can see and feel ourselves improving. But those gains are short-lived.
“If learning can be defined as picking up new knowledge or skills and being able to apply them later,” writes Brown, “then how quickly you pick something up is only part of the story. Is it still there when you need to use it out in the everyday world? The rapid gains produced by massed practice are often evident, but the rapid forgetting that follows is not.”
Massed or blocked training is repeating the same exact technique over and over—think hitting fifty reps in a row with your seven-iron or practicing the same soccer move without opposition fifty times in a row. The science tells us that when we block our training, with each subsequent repetition, our brain devotes less energy to going through the process of solving the problem before us.
For example, I saw Dr. Tim Lee, a leading researcher in this space, demonstrate this to a crowd of golf coaches with a simple math problem. He asked them to come up with the answer to the following multiplication problem: what is 21 x 14? Coaches went through the problem in their heads and slowly hands came up as they came up with the answer. Finally he called on a raised hand. “294!” shouted the coach. “Correct,” said Lee. “How did you come up with that?” The coach went on to explain how he went through the process of multiplying 21 x 10 and then 21 x 4 and then adding them together.
“Ok, next problem,” said Lee as he advanced his slide. The next problem came up: what is 21 x 14?
The audience chuckled, and someone shouted triumphantly, “294!” We all laughed, and Lee asked us about the process we went through to come up with that answer the second time around. We didn’t. We already knew the answer. “This is similar to what the brain does when we block our practices,” said Lee. Every time we repeat the same exact motion, we devote less time to going through the process. We shout out the answer, and this slows down learning as it allows the brain to divert its attention away from the skill you are trying to develop.
Research demonstrates that interleaved training—solving different math problems instead of the same ones repeatedly—promotes mastery and long-term retention when compared to massed practice. Interleaved training mixes and matches various techniques and skills, usually in a game-conditioned setting. Many practitioners call it “repetition without repetition.”
The main reason is that interleaved learning engages different parts of the brain. Neuroimaging has shown that motor skills learned from massed practice seem to be consolidated in areas of the brain used for cognitively simple and less challenging motor skills, what we might call factual knowledge. Interleaved learning is consolidated in areas associated with learning higher-order motor skills and provides conceptual knowledge, an understanding of when and how to deploy a skill in relation to its environment.
Writes Brown, “The varied and more challenging practice demands more brain power and encodes the learning in a more flexible representation that can be applied more broadly.” In other words, if you want to be able to call upon it more readily, it needs to be learned with more struggle.
If you are an ice hockey coach, for example, instead of doing an entire practice on skating or passing, you would incorporate multiple elements into your session. USA Hockey’s ADM is excellent at this, setting up six stations on a sheet of ice and having players learn something new at each one. In the short term, athletes may experience a feeling of frustration and think, I was just getting good at that, and we moved on. But in reality, the interleaving of these skills trades short-term satisfaction for long-term learning, and next week the hockey player will retain more of the previous week’s session than if he had only worked on one aspect of his game.
(John O'Sullivan is the founder of the Changing the Game Project and the host of the Way of Champions Podcast. His latest book, Every Moment Matters: How the World's Best Coaches Inspire Their Athletes and Build Championship Teams, from which this article was excerpted, came out in December of 2019. It is available in paperback and Kindle. His previous books are, Is It Wise to Specialize?: What Every Parent Needs to Know About Early Sports Specialization and its Effect Upon Your Child’s Athletic and Changing the Game: The Parent's Guide to Raising Happy, High Performing Athletes, and Giving Youth Sports Back to our Kids.)