In contrast, anaerobic exercise-induced stimulation of testosterone production was explained by the effect of the anaerobic glycolytic pathway on the release of gonadotropin releasing hormone (GnRH) and LH . Cadoux et al. injected radiolabeled testosterone in men who underwent vigorous aerobic exercise for 50 min. Aerobic exercise can provide a large physiological stress to the body, resulting in a corresponding response of the neuro-endocrine system. Cumming et al. showed that both testosterone and luteinizing hormone (LH) synchronously peaked at 20 min of progressive intensity exercise on an ergometer. Daly et al. likewise showed that, despite rapid increases in T-Testo after 30 min of endurance running, the levels significantly decreased 90 min into the recovery. The results demonstrated that a combination of a moderate intensity, higher volume, and shorter resting periods between sets can acutely and significantly increase the post-exercise T-Testo. However, Charro et al. reported that, when the total volume of the load lifted is fixed, both the variable and constant exercise intensities produce similar acute changes in T-Testo in healthy young men. Arazi et al. studied young and middle-aged men who underwent an 8-week-long progressive resistance training program. All three groups exhibited an increase in T-Testo post exercise, with middle aged and older men showing similar relative testosterone concentration changes to younger men. Thus, whether exercise can still potentiate testosterone spikes in overweight and obese individuals is uncertain; and if present, they seem to be inferior to those seen in lean/normal weight men. Studies have investigated the associations between the degree of physical activity and basal plasma testosterone concentrations. Another study by Velasco-Orjuela et al. evaluated the acute effect of high-intensity, resistance, or combined exercise protocols on T-Testo in inactive overweight men. The sustainability of exercise-induced elevation of testosterone concentrations may not vary between endurance and resistance exercise; however, the underlying mechanisms may be different. This can be manifested by an initial rise in plasma testosterone concentrations secondary to a catecholamine surge and testicular stimulation, followed by increases in cortisol levels, a hormone that inhibits testosterone production . Galbo et al. reported that, in young healthy men, a significant increase in T-Testo (~31%) was observed after 40 min of maximum intensity (reflected by the individual’s highest oxygen uptake) during exhaustive treadmill running. These data support the notion that intensity is required to alter plasma testosterone concentrations. The study subjects in ergometer cycling studies included elite athletes, moderately active people, sedentary people, and people with obesity. Endurance or aerobic exercise refers to any type of cardiovascular conditioning where breathing and heart rates increase for a sustained period of time. Sudden elevations in cortisol can quickly reduce testosterone. Research often highlights the dangers of long-term stress, which can elevate levels of the hormone cortisol. Exercise is one of the most effective ways to prevent many lifestyle-related diseases. Testosterone is a steroid hormone that the body mainly produces in the testicles and ovaries. Our results suggested that an increase in physical activity greatly affected the increased serum testosterone levels in overweight and obese men during lifestyle modification. These results suggest that an increase in physical activity greatly affected the serum testosterone levels in overweight and obese men during lifestyle modification. Previous studies have suggested that aerobic exercise training resulted in increased serum testosterone levels in men. For the first time, we have shown that an increase of physical activity level has greater effects on circulating testosterone levels than calorie restriction during lifestyle modification-induced weight reduction (combination of aerobic exercise and calorie restriction) in the present study. However, it is unknown whether increased physical activity or calorie restriction during lifestyle modifications has a greater effects on serum testosterone levels.
