Originally Posted by MikeM
So, what's the line? How much soreness is acceptable? Or is it all mental? If your brain isn't gung ho, then you call it and move on?
One thing that's important to learn is the difference between physical fatigue and CNS fatigue. When the CNS is tired or beat down, most warmup sets will feel like a ton. This is a red flag to me, and it's best to dial down the training for that day.
CNS fatigue could be from training, or it could be from something as simple as your body fighting a virus. If you've had some pretty heavy squat and deadlifts sessions within the last few days and the weights start to feel heavy on subsequent workouts, then it's probably lifting related.
Physical fatigue, on the other hand, is a more unique beast. Down days are not always from "over-reaching" while training. If you have 2 days in a row where you physically feel like a slug and your body feels like a wreck, it's likely the cause is from over-reaching and a few days off wouldn't hurt.
One thing you don't want to do is plan an extended deload period based on one bad workout or day. All too often you will see someone have an off day in the gym and post something like:
"Bad day. Couldn't hit any PRs and felt tired. Going to take a deload week."
Here are some truths I have learned over the years:
-1/4th of my workouts suck for no reason.
-When I feel like crap before a workout I often set PRs during the workout.
-When I feel awesome before a workout I often have a flat workout.
We have to be careful over-analyzing how we feel. It's not always a good indicator of athletic performance. If your CNS is making everything feel heavy, back off. Don't risk injury.
If you have 2 days in a row where you feel sluggish and your body feels beat down, take a few days off. Take things day by day and hit the gym when you feel mentally ready for a workout, but don't force a week long deload when it might not be needed.
Ignore your mental state or physical fatigue that isn't accompanied by CNS issues or by your body feeling beat down.
These are my own personal guidelines. Mileage may vary. Above all things, listen to your body.