Effects of eight-week regular high-intensity interval training and hemp (Cannabis sativa L.) seed on total testosterone level among sedentary young males: double-blind, randomized, controlled clinical trial

Purpose This study aimed to investigate the effects of high-intensity interval training (HIIT) alone or in combination with hemp seed on total testosterone (TT) levels, sex hormone-binding globulin (SHBG), body composition, oxidative stress, and antioxidant capacity in sedentary young males. Methods Randomly, 48 young sedentary males were assigned among four groups (each comprising 12 individuals) as follows: HIIT + hemp seed (HH), HIIT + placebo (AT), hemp seed only (HS), and control. For eight weeks, exercise groups had HIIT three times per week. Hemp seed groups received 2 g of powder daily. The plasma levels of TT, SHBG, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), and also body mass index (BMI), body fat percentage (BF%), and muscle mass percentage (MM%) were measured. The analysis was based on the intention-to-treat (ITT) and per-protocol (PP). Results Based on ITT, BMI and BF% decreased, and MM% increased significantly post-intervention in HIIT groups ( p < 0.05). TT increased significantly in the HH [mean difference 0.45, 95% CI 0.1 to 0.7, p = 0.005] and AT [mean difference 0.37, 95% CI 0.1 to 0.7, p = 0.01]. The whole hemp seed components showed a significant antioxidant potential. However, none of the SOD, CAT, and MDA indices showed significant changes post-interventions ( p ≥ 0.05). Conclusion Finally, HIIT and hemp seed intake showed no significant effects on the antioxidant defense system. However, regular HIIT significantly increased TT levels and improved body composition in sedentary young males. Trial registration Iranian Registry of Clinical Trials (registration code: IRCT20140907019082N10).