Feeling crap > feeling great

The single biggest issue I have with training is relating how I feel to the progress I am making. 

The whole point of doing workouts is to "damage" your body so that it reacts by repairing itself and getting stronger in the process.

So pretty much by definition if you are feeling 100% then you are not training hard enough.

However just how bad can you feel?  

The received wisdom in training bibles is not to overdo it. They emphasise the dangers of "overtraining".

The trouble is individuals clearly differ in terms of how much damage their bodies can absorb before this risk becomes a reality.

For me I can't say I have ever come close, despite some pretty extreme training levels. To the contrary the harder I work the better I feel. If I feel crap it quickly passes and I know its a good sign as I'll feel even stronger soon.

A case in point is earlier this week.  I felt run down but forced myself to complete my workouts and also double up with a max strength weight session setting a new PB for my deadlift.

Yesterday I did a "tired 20" and felt like a god. Easily pumped out the target 1500kcal in a couple of hours and was really strong during the 20 averaging near 300W. 

FWIW my personal opinion is that for amateur cyclists the fear of overtraining is a lot more debilitating than the reality.