On skills and techniques - that is. It turns out that when we're unable to take part in our favorite outdoor activities, visualizing ourselves doing the activity could still yield improve results when we get back to it IRL.
In 1995 Dr. Pascual-Leone discovered that people visualizing how to play the piano learned a sequence just as well as those who actually practiced the sequence by hand. Neurologically, they had the same changes in their brain as people who practiced in real life.
But that's small, what about bigger things that require more muscle?
In the famous 1996 "free-throw" study, Dr. Blasotto tallied a bunch of free-throws from three study groups before and after 30 days of the following:
1. No touching, practicing, playing basketball
2. Practice shooting free-throws for a half hour each day
3. Go to gym, sit with eyes closed visualizing making and sinking free-throws for a half hour each day.
After 30 days of these activities, the first group showed no improvement.
The second group showed a 24% improvement.
And... the 3rd group... improved by 23%
The visualization group improved by almost the same amount as those who practiced with their muscles. It's as if their brain didn't get the memo. (or did it?)
It's no secret that many of the world's top athletes visualize success before something big happens, but what they don't tell you is what are they actually visualizing. Are they visualizing "winning everything" and "standing on top of that podium?" Maybe they'll admit that they did at some point, but that isn't the kind of visualization that got them up there in the first place.
I'll cite one more study from 2005 before making my point. Merely imagining flexing a muscle 15 minutes daily for 3 months increased the muscle's strength by 35% ! It should be noted that the muscle in the study was the little-finger - BUT STILL!
What winning athletes are really visualizing when they "win it all" is the activity itself - never the prize at the end. You're visualizing the process, the activity; because it's fun, and you want to be better at it. Turns out, when you're visualizing those things, very vividly, your brain is treating it as physical practice, and the muscle memory could yield results. I'm not sure of a full 35%, but if you're improving for you, then any improvement is worth while.
The trend for benefits in visualization do tend to be more technique based - even though the "little-finger" study is convincing for muscle gainz... Studies on activities like tennis and golf strokes, ice skating, and shooting a basketball seem to indicate that our brain can learn a technique by processing the visualization or "imaginary activity" as if it were real. As far as your brain is concerned, visualizing the technique is physical practice.
So, how would we make the most use of all this information?
First off, before you do an activity, even for the first time, I think you can benefit from visualization. Once you've visualized, it's time to do. Whatever you've visualized, it probably won't be exact until you have a real-life experience. (Like in the basketball study, if you've never touched a basketball a day in your life, I'm pretty sure the visualization is only going to be so helpful. I would argue that it matters if the person has ever thrown a successful free-throw ever before.)
But, once you've done it and have muscle memory of what it feels like, you're able to visualize those muscles firing! That is where visualization REALLY comes to life! Being able to very vividly visualize a technique will be more effective after your brain-body connection has done it a few times.
I do believe that our brains are very powerful, and neuroscience is only scratching the surface of what we're capable of. I'm not sure that the mechanisms behind why these studies work is as cut and dry as they suggest, however. I think that part of the improvements could just be from rewiring the brain to be more disciplined and focused. Stay with me on this one. It may not be the fact that you're visualizing flexing the finger that makes it stronger. It could be that you had the discipline to focus even when you didn't want to and therefore next time you wanted to quit, your mind was more focused and resilient. I'm just saying, that could be another reason why these studies show improvements. There are even studies that suggest we can imagine/visualize increasing performance and levels of immune cells in our bodies. It wouldn't hurt to try it.
AND, for the current Covid 19 outbreak, you can rest easy knowing that if you lay down, close your eyes, and visualize performing your favorite water sport activity for an hour you'll get better at it... Might as well tack on 15 min for some immune boosting visualization too!
Your brain doesn't know the difference.