600mg/week a LOT of testosterone. From what I understand 200mg of enanthate/cypionate will typically bring a mid 20s male into high-normal levels and 300mg is definitely supraphisological. In the SCU study (Performance enhancement and urinary detection after short-term testosterone enanthate use) the subjects had significant gains in lean mass on 3.5mg/kg.

Supraphisiological doses of testosterone may inhibit collagen synthesis or it might not. W're still really not sure on that one. The winstrol brittle tendon theory is complete broscience. It's entire basis comes from one unconfirmed study in rats. LanceSTS knows more about that particular bit of bullshit than I do.

The truly frightening thing about the SCU study is that half the participants still had a T/E ratio < 4:1 while taking 300mg/week i.e. did not fail the WADA drug testing standard while taking a significant PED.