Rune I will talk to Mike Smith from build a better runner fame to get you the most accurate answer on your question. Will try to update by tonight in night class now.
Edit:
Here is something to us started. I know this could be true for men too but I believe it is important to note the difference between a circuit (lots of distance coaches do this) Vs. a heavier/more intense type of lift.
Hormone Function in Resistance Exercise: Volume of Training
In resistance exercise, total volume is easily calculated by the number of reps x sets x weight that is performed in either a single session of resistance exercise or during a long-term resistance training program. Marx et al. (2001) examined the long term training (6-month training regime) adaptations associated with a low-volume (circuit) resistance training program versus a periodized high-volume resistance program in college-aged women. The study showed that the periodized higher volume resistance program had higher testosterone, insulin-like growth factor-1, and decreased levels of cortisol after the 24 weeks of training when compared to the circuit program. Greater increases in muscular strength, power, and speed were also seen in the high-volume group.
Smilios et al. (2003) examined the acute effects of the number of sets on testosterone, cortisol, and growth hormone responses after maximum strength (5 reps at 88% of 1RM, 3-min rest) and muscular hypertrophy (10 reps at 75% of 1RM, 3-min rest) protocols with 2, 4 and 6 sets of each exercise in 11 physically active (2-8 years resistance training experience) young men. Subjects also did a strength endurance (15 reps at 60% of 1RM, 1-min rest) protocol with 2 and 4 sets. In the muscular strength protocol, the number of sets did not affect the hormonal profile. In the muscular hypertrophy and strength endurance protocol, there was an increase in cortisol and growth hormone levels in four sets of exercise versus two sets. In this study, there was no significant increase in testosterone in any of the testing conditions. Contrariwise, Kramer and Ratamess (2005) summarize that protocols high in volume do tend to produce acute hormonal elevations in testosterone, as well as cortisol, and growth hormone.
"Nature hides her secret because of her essential loftiness, but not by means of ruse." -Albert Einstein