Exhaustive endurance exercise such as cycling has been shown to decrease testosterone levels for up to 72 hours after exercise [ 1 1
Other research has suggested a link between endurance-trained athletes and low resting testosterone levels [ 2
[1] Anderson, T., Lane, A. R., & Hackney, A. C. (2016). Cortisol and testosterone dynamics following exhaustive endurance exercise. European journal of applied physiology, 116(8), 1503–1509. https://doi.org/10.1007/s00421-016-3406-y
[2]
Daly, W., Seegers, C. A., Rubin, D. A., Dobridge, J. D., & Hackney, A. C. (2004). Relationship between stress hormones and testosterone with prolonged endurance exercise. European Journal of Applied Physiology, 93(4), 375–380.
https://doi.org/10.1007/s00421-004-1223-1
