I think there is something to this and it has to do with hormonal function. More specifically, low testosterone/adrenal function.
I have suffered from low energy all the time and I just started on a herbal supplement regimen that is really starting to help. In fact, I feel like I did before this started. My sleep is improving, energy up/ strength up:


Jarrow Sensoril(boosts testosterone/adrenals/thyroid--reduces stress-enhances memory) 1x daily
Symbiotics Colostrum(boosts immune system/increases growth hormone/healing gi tract issues) 2 caps 2x daily
New ChapterWhole Foods Multivitamin(better absorbed than standard multi) -