Sick..... Again

I have always been under the impression that overtraining is not a result of a specific amount of training, but rather your body's inability to adapt to the increasing demands being placed upon it.

 In other words:

 VT (not =) POT     [Volume of Training is not equal to the potential for overtraining]

 But rather

 DeltaVT = DeltaPOT     [Change in the volume of training is equal to the change in the potential for overtraining]

 Similarly

 DeltaIT = DeltaPOT     [Change in the intensity of training is equal to the change in the potential for overtraining]

Of course there are many other factors. Rest as mentioned is number one in my book with nutrition a close second. However, age plays an increasing role particularly when you get old and slow like me.

Are you working a lot of hours, getting less sleep than you should, or otherwise stressing yourself in addition to training?

I ask because everytime I get "run down", I get sick.  I know it's just anecdotal and not scientific, but I've had it happen many times when I'm taxing my body too much.