Testosterone, Growth Hormone and IGF-1 Responses to Acute and Chronic Resistive Exercise in Men Aged 55-70 Years

By Ty Sevin, Aug 31, 2021

< Back to Benefits of Strength Training on Hormonal Responses in Older Adults

B.J. Nicklas, A.J. Ryan, M.M. Treuth, S.M. Harman, M.R. Blackman, B.F. Hurley, M.A. Rogers, Department of Kinesiology, University of Maryland, College Park, MD 20742, Endocrinology Section, Gerontology Research Center, Baltimore, MD 21224.


The investigators tested the responses of a variety of anabolic hormones to a single bout of heavy strength training and to a 16 week strength training program, in 13 men aged 55-70. Body composition and muscle strength were assessed before and after the training program. Fasting blood samples were taken on 2 consecutive days prior to training and again on 2 consecutive days after the last day of exercise. To determine single bout responses, blood was also drawn immediately before and 10 minutes after a single exercise session during the last week of training.


The training program resulted in a 37% increase in upper body strength and a 39% increase in lower body strength. Lean body mass increased and percent fat decreased. In response to the single bout of exercise, testosterone levels remained unchanged but growth hormone levels increased 18 -fold immediately after training. The baseline levels of testosterone, growth hormone, and insulin like growth factor I were unaffected by the 16 week training program.


Results indicate that a single bout of strength training causes a substantial human growth hormone response in older men, but 16 weeks of progressive resistive training does not affect beginning concentrations of growth hormones or any other anabolic hormones. This confirms the results of other studies which show that the immediate increases in growth hormone levels after training are not maintained or built upon. Instead these levels return to beginning levels shortly after each training bout.

Keiser Equipment Used

Leg press, chest press, leg curl, lat pull down, leg extension, shoulder press, hip abductor & adductor, upper back, triceps press, lower back, and abdominal machines.

Published in International Journal of Sports Medicine, vol. 16 pgs.445-450, 1995 Abstracts #7 & 8 -Bone Density also refer to hormonal responses.

Link to Original Research

About the author

Ty Sevin

Director of Human Performance, Education and Research

Articles by Ty Sevin >

With over 25 years of coaching experience at both the collegiate and Olympic levels, Ty Sevin is one of the most influential track and field coaches in the country. Ty has worked for the United States Olympic Committee, serving as the Director of the Track and Field Residency Program at the USOC Olympic Training Center in Chula Vista, CA. He has also served as an assistant coach for Team USA on three separate occasions, for both the men’s and women’s teams. Ty himself was a four-time U.S. Olympics Trials qualifier in javelin. Ty most recently spent four years as the Associate Head Coach at the University of Texas at Austin for both the men’s and women’s track and field teams. Prior to that, he led the men’s and women’s track and cross-country teams at the University of New Orleans and McNeese State.

Currently, Ty applies his vast industry experience to the role of Director of Human Performance, Research and Education for Keiser Corporation, where he consults with college and professional sports teams regarding the utilization of Keiser strength equipment. He is also responsible for creating educational curriculum relating to human performance and overseeing Keiser research projects