Objective: To examine the effects of long-term low-to-intensive cycling training on seminal cytokines and semen parameters in male road cyclists.
Design: Repeated measures design.
Setting: The Exercise Physiology Laboratory of the Urmia University.
Participants: Twenty-four healthy nonprofessional male road cyclists (23.1 ± 6.2 years) participated in this study.
Interventions: All subjects participated in a 16-week low-to-intensive cycling training. The semen samples were collected, respectively, at baseline (T1), immediately (T2), 12 (T3), and 24 (T4) hours after the last training session in week 8; immediately (T5), 12 (T6), and 24 (T7) hours after the last training session in week 16; as well as 7 (T8) and 30 (T9) days after the last training session in week 16.
Main outcome measures: Semen volume, sperm motility, sperm morphology, sperm concentration, and number of spermatozoa as well as seminal interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α in seminal plasma from male road cyclists.
Results: The levels of seminal IL-1β, IL-6, and IL-8 increased (P < 0.008) and remained high after 30 days of recovery. Semen volume, sperm motility, sperm morphology, sperm concentration, and number of spermatozoa decreased (P < 0.008). All of the above-mentioned variables (with the exception of semen volume, sperm motility, and sperm concentration) remained low after 30 days of recovery (P < 0.008).
Conclusions: A 16-week low-to-intensive cycling training may have deleterious consequences for spermatozoa and hence may have an impact on male fertility among cyclists.
Clinical relevance: Given that exercise can affect reproductive system among male cyclists, hence cyclists may routinely employ sufficient rest after their training sessions to ensure that the sperm healthy parameters and seminal immunological profiles have properly recovered from the last training sessions.