I really like this advice. I haven't felt sore in the gym in a while and that's when I know it’s time to lift HEAVY! I always have high volume in my routine but once i start losing that soreness, I know it's time to shock the muscles and lift till failure.

Like Scott says this is the best time to have a spotter because towards the end you should definitely be failing and yelling at the weight to get it up!

All the comments here are great advice. Good job everyone!

I've been working out for quite some time as well, and when i'm not getting sore from my workouts, I know it's time to switch up the routine, throw some new exercises in there, and even switch up the weight or throw in some drop sets or super sets!  The body is such an amazing mechanism and it adapts so well to everything we throw at it! So keep switching up the routines pretty often and I guarantee you'll not only be sore, but the progress and gains you'll make will surprise you! 

Keep working hard and smart!

Cheers,

Mike