Testosterone

Testosterone is the primary male sex hormone and an anabolic hormone involved in protein synthesis and tissue growth.^{1Rippetoe et al., Practical Programming for Strength Training, 3rd ed., p. 96.} It is also linked to neuromuscular efficiency, bone growth, glycogen reserves and red blood cell production.^{1Rippetoe et al., Practical Programming for Strength Training, 3rd ed., p. 96.} Women have about 15 to 20 times less circulating testosterone than men.^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 92.} The NSCA describes prepubescent boys as producing too little testosterone for noteworthy hypertrophy.^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 91.}

In young men whose testosterone was driven very low while other anabolic signals were left intact, strength and lean mass gains were smaller than in men with normal levels.^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 92.}

In practice

• In boys and younger men, testosterone can rise with large-muscle exercises such as the deadlift, power clean and squat; loads of 85 to 95% of 1RM; moderate to high volume; rests of 30 to 60 seconds; and two or more years of training experience.^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 91.} Total testosterone rose after deadlifts but not bench presses.^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 91.}
• In men, elevations have been found for up to 30 minutes after resistance training.^{4Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 118.}
• Most studies find no acute increase in women or a small increase, sometimes only in free testosterone.^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 92.},^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 91.} Their androgen receptors upregulate much faster than men’s, likely to make better use of the testosterone present.^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 92.},^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 91.}

Acute hormone responses

The NSCA calls the acute anabolic hormone response critical for performance and later adaptation.^{4Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 118.} Rippetoe describes limited evidence that any exercise raises testosterone, with weight-training studies showing increases, decreases or no change.^{1Rippetoe et al., Practical Programming for Strength Training, 3rd ed., p. 96.} Schoenfeld judges acute hormone elevations’ role in hypertrophy unclear and likely minor, placing more weight on chronic production.^{5Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 32.}