Our ancestral human woke in the morning to the rising sun. The sun’s light and warmth and the cortisol spike stop melatonin production and wakes up the brain and body. The blood pressure rises and the body temperature increases. Interestingly, testosterone peaks as well. This is interesting because cortisol and testosterone are said to have an antagonistic effect. Studies have shown that injected cortisol will drop testosterone levels. And there is mild to moderate association of increased cortisol from exercise correlating with decreased post workout testosterone. But it seems the science is not really settled on the matter, and it is a complex topic. The same science does show an almost matching curve in the daily fluctuations of both testosterone and cortisol when cortisol is averaged. It is usually shown as a smooth curve rather than the actual major zig-zags of the ups and downs. But both tend to peak in the morning and decrease during the day.
© 2025 Troy
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