You are overtraining. Sounds pretty bad, doesn't it? Except, overtraining is a BEAUTIFUL thing...why?

An easy correlation can be made to a guy who runs

You can be in great shape, but if you're flippin' tired, you can't perform that well. Unfortunately, it takes ALOT OF HARD WORK to get in great shape, and that causes fatigue to accumulate.

Your FITNESS might dictate that you can PERFORM a bench of 300 lbs, but because you're FATIGUED (tired), you can only PERFORM a bench of 250

Eventually, you get to the point where you are thoroughly busting your ass and you are starting to see that fatigue overtakes you (overreaching/overtraining phase). So at this point, fatigue has "won" (albeit temporarily) so many trainers will just quit for awhile (a week, sometimes weeks, sometimes several months). This is the ultimate in "missed opportunities"

The thinking man's trainer decides to take advantage of this by PLANNING to do this, using "Dual Factor theory". He increases his fitness levels using increasing levels of volume and/or weight and/or frequency and once he reads that fatigue has overtaken his body's recovery ability, he drastically cuts back on his frequency and/or volume and/or intensity. This allows for an active rest, so fatigue dissipates. however, he is STILL TRAINING, and his fitness levels continue to climb (or at least stay the same) while he 'rests'.

After a period of time...perhaps a "cruise" of 1 or 2 weeks, or perhaps an "active deload" of 3 weeks, or a "strategic deconditioning" period of 10 days, you are still "in shape" because you've been training, but you are well-rested, and you are ready to attack the weights again.