After the third decade of life, men start to have ~1–2% decrease of testosterone per year (13). Estrogen promotes growth of uterine tissue and breasts, maintains libido and secondary sexual characteristics in females, whereas progesterone has a significant role in the female menstruation cycle and pregnancy. Moreover, they are also involved in other processes, such as regulating cholesterol levels and determining inflammatory response. A significant proportion of SCD events occurs in patients without any known cardiac disease, and even in the presence of diagnosis of a cardiac disorder, current knowledge on prediction of arrhythmic risk is limited (2). It is well-known that gender is an independent risk factor for some types of cardiac arrhythmias. Thus, the ability to monitor TL through objective measures may enhance understanding of individual training responses and reduce the risk of maladaptation (16, 21). Well-planned exercise training programs attempt to balance both acute and chronic training loads (TL) in order to maximize physiological adaptation and attenuate the risk of maladaptation (6, 16, 21). Assessment of HRVdaily may be a clinically valid proxy measure for monitoring hormonal changes throughout a training intervention. The FDA and pharmaceutical companies may want to consider testosterone replacement that would benefit testosterone-deficient women. However, these opinions are not substantiated or validated with any scientifically published data. Out of more than 3500 studies that were given to the committee to be reviewed, only a very small fraction, 13 studies, were considered in their final recommendations. Heart rate increases, variability decreases, and the normal autonomic flexibility is impaired (Galetta et al., 2022). During low-stress periods, these associations weakened, suggesting the relationship is most clinically relevant when the stress system is chronically activated (Pruett et al., 2010). This is healthy and does not suppress HRV when the system is functioning properly. Trans people who do not have access to insurance or the funds to pay out of pocket have been using DIY HRT for decades, in which people access hormones through unofficial channels and take them without doctor supervision. In recent years, microdosing — or taking a low dose of testosterone — has become increasingly popular as a treatment option for trans people looking to ease into the effects of HRT. An important thing to note is freezing your eggs after being on testosterone involves going off HRT and possibly starting another form of hormone therapy to make IVF extraction easier. This genetically-determined disease is characterized by the appearance of a coved-type ST segment elevation in the right precordial ECG leads, and puts the patients at significant risk for SCD in the absence of an underlying structural heart disease (61). As mentioned previously, estrogen, progesterone and testosterone have varying effects on these currents, which could explain the gender differences (7). Female sex is known to be an independent risk factor, as females have 10–20 ms longer QTc intervals. Likewise, testosterone replacement was shown to exert cardioprotective effects in orchiectomized rats (48). In fact, there are reports of increased (29), decreased (32), or indifferent calcium currents (ICa) in females as compared to males (27). Keeping track of these signs and speaking with a healthcare provider when they appear is important for staying safe while on testosterone therapy. This could be due to an increase in red blood cells, which thickens the blood and makes the heart pump harder. When testosterone levels rise, the body may respond by increasing its internal temperature. This can make the heart beat faster than normal, especially after taking a dose or during peak hormone levels. A fast heart rate can happen with other symptoms that may affect health and quality of life. Injections may cause the most sudden changes and lead to fast heart rate in some people. This can affect how much of the hormone is active in the body and may have unknown long-term effects on liver and heart function. Prostate cancer is the second most frequent malignancy in men worldwide.4 In 1941, Huggins and Hodges37 were the first to demonstrate the beneficial effects of castration and estrogen injections in men with metastatic prostate cancer. In contrast to the use of TRT in hypogonadal men, androgen deprivation therapy (ADT) is commonly used in the treatment of advanced prostate cancer. Questions also have been raised regarding the methodological validity and statistical analysis techniques in the study by Vigen et al.27 Some systematic reviews and meta-analyses have suggested that the conflicting associations, and subsequent lack of firm conclusions, may be due to study heterogeneity and low-quality evidence. Testosterone can be converted to dihydrotestosterone (DHT) or 17β-estradiol (E2). Synthetic hormones are more likely to be animal-based and different in molecular structure from women’s endogenous hormones. However, the FDA has not approved any custom-compounded bioidentical hormones. The U.S. FDA has approved some forms of manufactured bioidentical hormones, including bioidentical estrogens and progesterone. Bioidentical hormones are man-made hormones derived from plants, often soy and yams, that are chemically identical to those the human body produces. These effects depend on the person’s age, health, and how testosterone is given. Thicker blood can raise blood pressure and may increase the risk of blood clots. TRT is a hormone therapy used to treat low testosterone in men with confirmed hypogonadism.