A basic question, not really related to the diagnosis issue: What is the best way to manage muscle fatigue that interferes with tasks you need to do?

For example, when you get fatigued, is it OK to rest until you can go back to the task, or is that not good in the long run? .... let's say you are chopping veggies and your arm muscles fatigue. Is it sufficient to wait until you can pick up the knife and chop some more, rest, chop, rest, chop until the job is done? Or is the short recovery, intermittant rest technique going to get me into more trouble -- like a more generalized fatigue? When that happens I can get winded very easily. It's a little scary, actually.

Thanks for any and all responses. I'm trying to get an idea of what it is like to live with this...

Happy holidays, all!
-Shari