Yeah Colin is spot on! Research shows that Arginine might not be that optimal to take PWO.
Though if I haven't totally forgotten the research it showed that:
(the numbers I don't remember, just using them as examples so the numbers really have no actual importance)
Arginine not in conjunction with working out= raise GH 3x
Working out =raise GH 4x
Arginine+working out= raise GH 2x (so lower than just working out but still raising)
Though sorry for not remembering, I might be TOTALLY OFF, so if I am I say sorry already...And hope someone will correct me if I'm wrong...
Edit: Found some abstract re. arginine and GH:
The subject ingested a dose of arginine (5, 9 or 13 g) or placebo (randomly assigned).
Mean resting GH values for the placebo, 5, 9 and 13 g day were 0.76, 0.67, 2.0 and 0.79 microg/L (n=6), respectively. Integrated area under the curve was not different with 13 g (197.8+/-65.7 min microg/L), yet it increased with 5 and 9 g compared with the placebo (301.5+/-74.6, 524.28+/-82.9 and 186.04+/-47.8 min microg/L, respectively, P<0.05). Mean peak GH levels were 2.9+/-0.69, 3.9+/-0.85, 6.4+/-1.3 and 4.73+/-1.27 microg/L on each day for the placebo, 5, 9 and 13 g days.
In conclusion, 5 and 9 g of oral arginine caused a significant GH response. A 13 g dose of arginine resulted in considerable gastrointestinal distress in most subjects without augmentation in the GH response. The rise in GH concentration started approximately 30 min after ingestion and peaked approximately 60 min post ingestion.