Maybe this is far fetch but lets see, for istance how healthy is the athelete before he starts his course or after 8 weeks on...
Is he falling ill ? If so, is it something that will clear up with a good course of antibiotics ? Remember, a gear course will first drop your immune system, so if you are sick now you will be worse shortly after and this will build up and maybe reach break point for some at week 8 and maybe only at week 12 for others. Most infections can easily be killed off using a course of antibiotics. Indeed there is the high possibility that you are a carrier. What is a carrier?
A carrier means that you carry a virus in your body at a level, which your immune system can control but it cannot put out the fire.As soon as you get on the gear your immune system drop and you can not fight the virus anymore...
How many times have you seen atheletes trying to gain muscle for two years without no success. Mostly they feel rundown, unmotivated, having problems sleeping. When studie someone who got all these symptoms blood you will mostly pick up that he is a carrier, his thyroid will be low to mid-normal and his globulin will be elevated, a clear sign of someone fighting an infection.
So my theory is that the 8 weeks will be determined by your immune system can this be...?