Example from the 1970s:
Circadian TT fluctuation…
Notice subject SFD. He is at the “pinnacle of manliness”, when men were men in terms of TT levels.
TEMPORAL VARIATIONS OF TESTOSTERONE LEVELS IN THE PERIPHERAL BLOOD PLASMA OF MEN in: Journal of Endocrinology Volume 61 Issue 1 (1974)
Here’s his daily variation with respect to max TT every day…
Notice anything strange?
Yes, correct. SFD’s INTRADAY PEAK is what many today have for a WEEKLY TROUGH (200-250 mg/week TC E7D):
take a look.