I've had the same issue when I first did my "leg day."
I've read that the reason your muscles feel weaker or unresponsive is due to high levels of lactic acid created during your previous workout. The acid dissipates after a while, but while it's there it blocks signals to your nerves from your brain so you aren't able to use your muscles as ably as you normally would.
I've read that the reason your muscles feel weaker or unresponsive is due to high levels of lactic acid created during your previous workout. The acid dissipates after a while, but while it's there it blocks signals to your nerves from your brain so you aren't able to use your muscles as ably as you normally would.