Variations of serum testosterone concentrations after physical exercises of different duration

• Published in: International journal of sports medicine Vol. 5; no. 5; p. 246
• Main Authors: Guglielmini, C, Paolini, A R, Conconi, F
• Format: Journal Article
• Language: English
• Published: Germany 01.10.1984
• Subjects: Adolescent; Adult; Humans; Locomotion; Physical Endurance; Physical Exertion; Running; Testosterone - blood; Time Factors
• ISSN: 0172-4622
• DOI: 10.1055/s-2008-1025914

Serum testosterone concentration was determined before and after physical activities of different duration. The subjects under study were: (1) 7 competitive walkers before and after a 20-km race (average race time 1 h 30 min); (2) 9 middle-distance runners before and after 1-h training; (3) 16 marathon runners before and after a marathon run (average running time 2 h 33 min); (4) 30 ultramarathon runners before and after a 107-km race (average running time 14 h). Serum testosterone increased by 51.8% (NS) in competitive walkers, by 38.2% (P less than 0.05) in middle-distance runners, and by 44.9% (P less than 0.01) in marathon runners; it decreased by 31.9% (P less than 0.001) in the ultramarathon runners. These findings, and similar variations of serum testosterone observed in an ultramarathon runner during a 6-h training session, suggest that serum testosterone increases during physical activities lasting up to 3 h and decreases to or even below the pre-exercise values for longer physical efforts. The possible mechanisms responsible for these differences are discussed.