interesting study that showed that testosterone levels in men and women fluctuate seasonally. The highest levels are found in the fall for both sexes, but lowest during the summer. Interestingly, birth control eliminated these seasonal variations and resulted in a "flatter seasonal testosterone profile".
So, maybe mean cycle, but on a much different time scale? Interesting thought.
Testosterone levels fluctuate seasonally, with the peak production in the fall of the year. Contrast that with LH, with it's peak in the spring of the year. This study found that men with Klinefelter's syndrome had only seasonal fluctuations of testosterone, suggesting a testicular independent role. This is a small study.
This study looked at T:E2 levels in men for seasonal fluctuations. What is interesting, is that the T:E2 ratio is at it's lowest during the fall months and highest during the summer months. This does conflict somewhat with studies that have looked at seasons fluctuations of T alone. But, it does correlate with changes in body habitus and activity levels.
another article discusses the seasonal variation of testosterone. Again, testosterone levels are shown to be highest in the fall months and lowest during the summer months. This has been found to be the case in both sexes.
This study suggests that "salivette" devices alter saliva hormone concentrations. Salivette's are usually cotton rolls in saliva tubes. At Seasons, we do not use the Salivette rolls.
negative correlation found with total testosterone, free testosterone, SHBG, and BMI. No correlation with sperm quality noted. Of interesting note, the summer season was associated with a decrease sperm concentration.
football lineman found to have increased heart dysfunction (increased left ventricular hypertrophy and increased left ventricular mass) and hypertension, compared to all other positions, throughout one season.
weight loss shown to have hormone component. Decreasing progesterone associated with weight gain. Saliva progesterone used to follow women in this study.
Increased strength training associated with increased Total Testosterone and 3-alpha androstane idol levels in trained athletes. This was not found in free Testosterone levels.