The term “muscle memory” is, of course, something of a misnomer. Muscles don’t make or store memories. They respond to signals from the brain, where the actual memories of any particular movement are formed and filed away.But muscle memory — or “motor memory,” as it is more correctly referred to among scientists — exists and can be quite potent. Learn to ride a bicycle as a youngster, abandon the pastime and, 20 years later, you’ll be able to hop on a bicycle and pedal off.To date, most studies of the effect of exercise on memory have looked at more intellectual tasks, like memorizing lists of words. In those cases, regular exercise appears to improve the brain’s general ability to remember.

Exercise = Productivity.

It seems so simple.

I thought it's best to vary your exercise so your muscles are always challenged?

really you only have to do that every two months or so

Cool. So any exercise will help with memory?

aerobic is what was tested...

But the Copenhagen scientists wanted to see how exercise influences the development and consolidation of physical memories. So before having their volunteers master the squiggle test, they first had a third of the group ride a bicycle at an intense but not exhausting pace for 15 minutes. The other two-thirds of the group rested quietly during this time.

Then, after the computer motor-skill testing, a third of those who’d previously rested completed the same strenuous 15-minute bike ride. The others rested.

All of the volunteers then repeated the follow-that-squiggle test after an hour, a day and a week, to see how well they’d learned and remembered that particular skill.

Their scores for speed and accuracy of squiggle shadowing were almost identical at the one-hour point, although the group that had ridden the bicycle after the first computer practice session was a bit less accurate.

After a week, though, things looked different. The men who had exercised just after first learning the motor skill were noticeably better at remembering the task, with their tracing of the red line on the computer more agile and accurate. The men who’d exercised before learning the new skill were not quite as adept now, although they were better than those in the group that hadn’t exercised at all.

What this result suggests, says Marc Roig, a postdoctoral researcher at the University of Copenhagen who led the study with his colleague Kasper Skriver, is that physical exercise may help the brain to consolidate and store physical or motor memories.

Consolidating a memory is not instantaneous, after all, or even inevitable. Every memory must be encoded and moved from short-term to long-term storage. Some of those memories are, for whatever reason, more vividly imprinted than others.

It may be that physical, aerobic exercise performed right after a memory has been formed intensifies the imprinting, Dr. Roig says. It makes the memory stronger.

That makes sense -- more blood pumping through the brain intensifies the imprinting.

Cool.