masturbation
 

Endocrine response to:-induced orgasm in healthy men following a 3-week sexual abstinence.
Exton MS, Krüger TH, Bursch N, Haake P, Knapp W, Schedlowski M, Hartmann U.
Source
Institut für Medizinische Psychologie, Universitätsklinikum Essen, Germany. [email protected]
Abstract
This current study examined the effect of a 3-week period of sexual abstinence on the neuroendocrine response to masturbation-induced orgasm. Hormonal and cardiovascular parameters were examined in ten healthy adult men during sexual arousal and masturbation-induced orgasm. Blood was drawn continuously and cardiovascular parameters were constantly monitored. This procedure was conducted for each participant twice, both before and after a 3-week period of sexual abstinence. Plasma was subsequently analysed for concentrations of adrenaline, noradrenaline, cortisol, prolactin, luteinizing hormone and testosterone concentrations. Orgasm increased blood pressure, heart rate, plasma catecholamines and prolactin. These effects were observed both before and after sexual abstinence. In contrast, although plasma testosterone was unaltered by orgasm, higher testosterone concentrations were observed following the period of abstinence. These data demonstrate that acute abstinence does not change the neuroendocrine response to orgasm but does produce elevated levels of testosterone in males.

PMID: 11760788 [PubMed - indexed for MEDLINE]

No wonder some of the guys i see in the gym aren't growing. I thought it was their poor diet and lack of rest. This puts a new slant on things.