I do early morning weight training two to three times a week. When I get a good workout I noticed the sleepiness in the afternoon too, but I still do not sleep

I do early morning weight training two to three times a week. When I get a good workout I noticed the sleepiness in the afternoon too, but I still do not sleep like my kids. To be clear, I don't have insomnia or a very difficult sleep, but the article is in general about sleeping less as you age. Leading a healthy lifestyle will definitely help get a better sleep, but now being around 40 years old, I just don't sleep like when I was a child, teenager or even in my late twenties. I don't need an alarm anymore for instance, I'll just wake up at 6am 6:30 no matter what I do.