I notice that the ECA stack seems to be more potent while on a cycle. This may be due to:
1) enhanced beta receptor sensitivity or increased receptor # in response to androgens.
2) blood concentrations of ECA remain higher during a cycle because your liver is somewhat compromised by anabolics, especially fina or orals.
I always use EC sparingly (25-50 mg, 2 or 3x/wk) on and off a cycle.