We often hear the term “Muscle Memory” used by fitness trainers…and this is actually a misnomer! The connections strengthened by repeated exercise reside not in the body’s muscles, but in the brain cells innervating them. Since repetitive training is required for learning a dance routine or riding a bike, we must repeat the new motions enough so that our brain’s striatum creates a “habit” of this motor routine. Once we’re expert enough at a particular movement, we can even do it “without thinking” (or at least, without deliberate attention to that task). We can walk and chew gum at the same time.
Scientists have learned quite a lot about which parts of the brain control movements by studying patients who have lost control of their bodies. Most notably in Parkinson’s disease, patients have trouble initiating a movement due to death of dopamine cells in their brain. However, even the most incapacitated Parkinson’s patient can still ride a bike or run from a burning building if someone yells “FIRE!” because these “reflex movements” are so well learned they occur in a different part of the brain that doesn’t require deliberate planning. They are more unconsciously motivated. See article here: “Cycling Provides a Break for Some With Parkinson’s“
For healthy people, varied movememts (or cross-training) are more beneficial than single-minded repetitions of one kind (e.g. jumping rope). Other factors like environmental stimuli, varied scenery and sensory inputs. may also be preferred to running a treadmill at home. You can try moving the treadmill in front of TV or just listening to headphones. These variants strengthen different connections of neurons than just the same old routine.
It’s not just about being ripped and flexing your bulging biceps at the gym. A recent study also reveals the mental health benefits of regular exercise “How Exercise Could Lead to a Better Brain” (from The NY Times). In particular, the brain’s natural chemicals are released during sustained cardio workouts, including growth factors that actually enhance memory skills and prevent neural death (e.g. Brain-derived Neurotrophic Factor), as well as mood lifters (i.e. dopamine and endorphins) that leave you feeling rewarded (or “high”) after a nice long run.
- How Exercise Can Prime the Brain for Addiction from NY Times blog
- How Exercise Can Help You Master New Skills in NY Times
- Exercise Can Be Too Much of a Good Thing for Some Men’s Fitness (on individual variability)
- Moderation As the Sweet Spot for Exercise from WSJ