It takes a lot of work to get stronger, faster, and better at things. Getting skill, in other words, is hard. Our bodies are kind of thrifty and a bit reluctant to change. There is a threshold we have to exceed when we gain ability or skill. Importantly, much less work is needed to keep training effects.
Muscle, just like other tissue or systems, needs an overload to respond with an adaptation. That is, to get stronger. The bottom line is that our body systems are essentially lazy. Many scientists would actually say that a bit differently and call it "efficiency," but it really comes down to the same thing—your systems will generate large and meaningful adaptations only if they have to.
You and I operate in the same way, basically. When we have to do something, usually we try to do the minimum needed first. Only if that fails to work will we pick up our efforts to the next more difficult or least costly step. This carries on until we have achieved what we set out to achieve. Kind of like an ebay auction. You don't go all in unless you have to.
Your brain and spinal cord does something similar when it comes to physical skills. The hippocampus is the main home for memory formation and storage in the brain. Your hippocampus is found under the frontal part of the cerebral cortex (cleverly named the frontal cortex!). It is named from the Greek "hippos" and "kampi" meaning "horse that is curved" based upon the anatomical shape of this region.
That the hippocampus was the seat of memory formation and storage was brought to light in the 1950s. This was based on a number of studies on "Henry M." or more commonly "HM". HM had intractable epilepsy and underwent neurosurgery that involved cutting through the hippocampus on both sides of his brain. A result was that HM can recall events from before surgery but is unable to make new memories.
Information gets stored as memories when there is activity in many neurons at the same time. This leads to an enhancement of information flow across certain connections due to what is known as "long term potentiation" or LTP. LTP is the process by which the memories are laid down and stored and requires input from multiple sites within the hippocampus.
An umbrella term has been used to describe many neural processes like motor skill learning, memories, or just changes in activity in the nervous system. "Adaptive plasticity" refers to the remolding of connections in the nervous system due to activity that has occurred. This can occur through a variety of means but the basic principle was suggested by the Canadian neuroscientist Donald Hebb.
In 1949 he came up with a statement known now as "Hebb's postulate:" "When an axon of cell A is near enough to excite a cell B and repeatedly takes part in firing it, some growth process or metabolic changes take place so that A's efficiency of firing B is increased." There's a shorter version, by the way, and has a nice rhyme that's easier to remember. "Neurons that fire together, wire together."
Let's say you have had all the neurons firing and wiring up together to gain some skill. It took a lot of work to get there, but you've reached some level. When we get really, really good at some skill it has basically become automatic. You can actually learn some things so well they become hard to forget! Those aren't just learned, they are "overlearned".
Overlearning was originally described by William Krueger from the University of Chicago back in 1929. He initially did experiments on memorizing lists of words, how much was needed for learning, and how much was needed to keep those skills up. Later he studied motor skill in a maze tracking task. The key point for our chat right now is that when people really learned tasks well (or "overlearned" them), they could maintain that skill with a whole lot less practice.
A lot of skilled tasks used in sports and often using tools are ones that are the easiest for us to forget. A long time ago the US Army realized this was a major problem for essential skills that infantrymen learned in basic training. As an example, it is important that a soldier knows how to assemble and dissemble his firearm. But this is just one out of a huge set of motor skills and tasks that recruits need to master during their basic training. But there is only a limited time to devote to each task or skill.
The US Army found that practice time devoted to a skill, like putting together and then taking apart the M60 machine gun, was sufficient to gain mastery during training. This, though, was rapidly forgotten after basic training. It is expensive and difficult to have "refresher" courses after training. So, overlearning was explored as a way to counter forgetting. It worked pretty well, actually, and a key point was that using refresher courses could reinforce the learning and offset forgetting.
This effect of overtraining has a "half-life" of about 3 weeks. This means that regular practice, even just a little bit, dispersed over weeks helps maintain the learning that occurred. This is just like the idea of needing to do some strength or cardiovascular work in order to maintain the benefits you might have from training. This is the "use it or lose it" idea.
And it applies really well to just about anything. I tell my martial arts students that even 5-10 minutes of practice each day improves the ability to remember and better movement skills. This took me a long time to truly appreciate. Years ago I used to think training had to be for hours at a time and if it was less than that it wasn't worth it. As you read above and below, of course, I was wrong. But I was also 22. It happens.
The Okinawan karate master and school teacher we met in a previous post, Gichin Funakoshi, wrote that "Karate is like boiling water: without heat, it returns to its tepid state". This is a great metaphor (and title for this post) that gets at the idea of making sure you do something will always help you maintain what you already gained.
So, if you are used to a big run or a big workout but over the holidays are instead running off to visit family, I suggest instead you do a short run. Or take a walk with your family. Doing something is always better than doing nothing. Even if you cannot do exactly what you normally would do. Find a few minutes to fit something in. Your body and brain (including your hippocampus) will be better off, you'll be better able to ramp up your activities again later, and you'll feel good too. Just apply a little heat to that water from time to time and it will keep you warm later.
© E. Paul Zehr (2011)