Following exposure to heat stress at 41°C for 12 h is significant increase in clusterin mRNA expression in rats’ Sertoli cells. In addition, heat stress affected individual hormone levels and reduced steroidogenic enzymes, Cyp11a1 and Hsd3b1, in Leydig cells. When you keep your testicles at the right temperature, they produce testosterone at much healthier levels than when they are repeatedly exposed to heat. And for males, cold water swimming resulted in increased testosterone levels. In most studies investigating the effects of sauna on the hormonal system, PRL levels increased 2- to 10-fold (Jezova et al., 1994; Jokinen et al., 1991; Kukkonen-Harjula et al., 1989; Latikainen et al., 1988; Leppäluoto et al., 1986; Sirviö et al., 1987Vescovi et al., 1990, 1992). Other studies demonstrated a less significant increase in COR levels in young women on day 14 of daily sauna use, which suggests that the body becomes familiarized with a hot environment (Pilch et al., 2003, 2007). The above could indicate that intermittent exposure to hot and cold stress partially stabilizes blood COR levels and alleviates stress in men who are regular sauna users. Serum COR levels decreased significantly, whereas a significant increase in TES was not observed during repeated thermal stress and cold water immersion. The aim of this study was to analyze the basic responses of the endocrine system in young healthy men with moderate and high levels of PA, who were exposed to heat during four 12-min sessions in a Finnish sauna. According to Kukkonen-Harjula and Kauppinen (2006), sauna is an ancient habit in both cold and warm climates, which is why cooling factors such as cooling time, temperature and the cooling environment (water or air) should be taken into account when analyzing changes in the hormonal milieu. There is a general scarcity of published studies investigating the impact of thermal stress on hormonal changes in men with different physical activity (PA) levels who are regular sauna users. If you’re taking hormone replacement therapy, you’ll need regular follow-up visits with a healthcare provider. As a result, your testicles make too little or no testosterone and sperm. Primary hypogonadism happens when your testicles aren’t making normal levels of testosterone. Healthcare providers consider testosterone levels below 300 nanograms per deciliter (ng/dL) as low in adults. Special cells (called Leydig cells) in your testicles make this hormone. The students declared the number of minutes dedicated to PA (minimum 10 min) during an average week preceding the study. The IPAQ was used only to select a homogenous sample of male students, and the results were presented only in terms of Metabolic Equivalent of Task (MET) units indicative of the participants’ PA levels. The participants’ PA levels were evaluated using the standardized and validated International Physical Activity Questionnaire (IPAQ) (Lee et al., 2011). The participants did not consume any foods or other fluids until after the final body measurements. They were asked to drink at least 1 L of water on the day of the test and 0.5 L of water 2 hr before the session. The study was performed on student volunteers who signed an informed consent statement. The cited authors did not observe significant changes in PRL levels during physical stress. Cumming et al. (1983) reported that an increase in the pharmacological doses of COR decreased TES production in humans. Cortisol affects metabolism by maintaining blood glucose levels at a sufficiently high level during physiological stress. COR is a catabolic hormone that is secreted by the adrenal cortex in response to physiological stress. For example, immersing the wrist in cold water for less than two minutes before a 20-minute cycling session led to increased levels of both testosterone and luteinizing hormone. By lowering inflammatory markers, cold therapy could help maintain healthier testosterone levels in the long run. This suggests that regular cold exposure may promote hormonal balance through improved body composition rather than directly increasing testosterone. While the research focused on young women and involved only partial cold exposure, it paved the way for more extensive studies involving whole-body cold water immersion, especially for older women. As we explore the interplay between cold exposure and testosterone, it becomes apparent that our environment, even the chill of an ice bath, can have deep implications for our hormonal health. Underwear held the testicles and scrotum very close to body, which heated them up significantly. Even a single session in a sauna will expose sperms to very high temperatures. One study found that placing a laptop at the level of your knees can increase the temperature by 1degC within 11 minutes.
