Is there an idiom or expression for "if you are not improving, that means you are deteriorating"
Thank you
use it or lose it
Here's an example of usage:
For several decades, people have used the term "use it or lose it" to aptly describe the best way to off-set the problems that come with aging.
In other words: use your brain, or lose your brain.
I usually hear this with the imagery of a rowboat: Like rowing a boat upstream, if you stop moving forward you fall back.
(searching for that phrase in google tells me that's a chinese idiom; I did not until just now know that!)
The more general phrase is: Standing still means falling behind.
(or similar variations like: If you're standing still, you're falling behind.
You could quote from the Red Queen, of Carroll's Through the Looking-Glass, when she expresses the the idea that you have to run fast, just to keep in the same place:
"Well, in our country," said Alice, still panting a little, "you'd generally get to somewhere else—if you run very fast for a long time, as we've been doing."
"A slow sort of country!" said the Queen. "Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!" — 1, p. 46