(Breather) In this show, on the heels of the 21 insights around the circadian clock, you’ll learn just how destructive excess artificial light is to your health and your overnight restoration, and you’ll also gain a better understanding of the complex interplay between your hormones and your lifestyle habits.Before we begin, if you happened to miss part 1 or just want to refresh what we covered last week, click here to listen to that episode first. Now, onto part 2! Here are some key points we’ll go over during this episode:Many postmenopausal women find exercise training extremely frustrating due to the fact that hormone response alters as they age. In contrast, men usually don’t lose their Growth Hormone (GH) levels until they’ve reached 50-55 years of age. They’re also protected by their testosterone levels, which persist throughout life (that is, if they’re not already suffering from inflammation, as that directly lowers testosterone levels), and GH and testosterone are the key players that work to keep a man’s heart and muscles in shape.But what happens when step 20, the surge of prolactin, is broken in modern humans? This used to be a more frequent occurrence among diabetics, but, because of our very common tendency to indulge in excessive technology usage after the sun sets, it’s started to pop up in all people, not just diabetics. And it’s no wonder, considering just how bright artificial lights tend to be! They’re so bright that they disrupt the usual circadian signals that come from the hormone response, which is why post-sunset light exposure reduces/blocks that surge in prolactin that our body is supposed to experience. This ties into sleep issues, as chronic lowered prolactin surges are associated with lower growth hormone secretion during the anabolic phases of sleep. (Note: since prolactin shows up a lot here, check out this great resource for everything you need to know about it, in case you want to learn more or gain a better understanding of how it functions.)One thing that will have an affect on your cardiac and skeletal muscle function is lowered chronic GH secretion. This is because it directly affects the process of autophagy. When GH is not released in normal amounts, it decreases lean muscle mass and increases fat percentage, not just in your body, but in all your organs! This is something to take extremely seriously, as it leads to slowly declining organ dysfunction and poor body composition. But what happens in normal aging in step 21?According to Dr. Kruse, “Aging is among the most common features found in studies on modern humans when DHEA and GH craters on hormone panels.” He also notes that the loss of the prolactin surge is noticeably frequent among postmenopausal women. Now, most women who are in the 35-40 age range are still in peri-menopause. And the higher their HS-CRP levels are, the faster they will enter peri-menopause, and the quicker they enter menopause. Unfortunately, they also age more quickly on a cellular level due to the fact that their circadian chemical clocks are sped up! Dr. Kruse also notes that women are more likely to face issues with leptin resistance than men because they already have higher leptin levels.Many older women face challenges like cognitive haze, loss of body composition, poor sleep, and increased levels of heart disease after menopause. It’s also quite common for doctors to blame these issues on the loss of estrogen (from ovarian failure), but the culprit actually lies with the loss of growth hormone and progesterone production. Think of progesterone as the “off switch” with anything that is pro-growth. Interestingly, modern women are often estrogen dominant…yes, even after menopause, because of “mismatches” in circadian biology. Unfortunately, many post-menopausal women struggle with cognitive loss, as well as a loss of (on average) 1% of their bone mineral density per year. This is largely because of the lack of progesterone, which corresponds to sleep issues in women. But taking the step to replace progesterone in women is something that causes a major effect on their sleep and bone density, as well as improving their memories and boosting cognitive function.