When i've been going at it for a long time yeah, cause practicing lots of legato just starts to your left hand tired and tense since that's all you are really using. I've learned to just take 5 minutes like every 30 minutes i'm practicing strictly legato, but you can do it ever 10 minutes or whatever works for you. And don't forget to breathe sometimes we just get so tuned out practicing a lick or w.e and don't realise we are holding breathe to focus, same idea as not forgetting to breathe when you're working out
@mericksonmusic