not feeling it

[Y_lifter]

I would never leave. I have been there and I usually:

Lower the weight and still do the Reps/Sets
Go do some cardio for 45 min or so and get real sweaty and pissed off at having to do cardio.(motivation)
Take a swim/sauna if you are able at the Gym.

It's kinda like not being able to get to sleep.
The longer you sit there trying, the harder it is.

Take a break and do something else until it comes back.

 

[The mann]

that's when you listen to your body and kick back a little.....you can't tain 100% all the time!

 

[CONTRACTION]

You will get more out of your workout if you are physically and mentally prepared. If you dont feel motivated or physically capable, just rest. Dont go deeper into an overtrained state. Usually I can tell by noon if it's a good day for me to workout and if I'm not up to it, I skip it. I usually feel 100% better the next day. IF I am already at the gym, I just make it a 20-30min workout and leave.