Scientists did an experiment where they hid people away from daylight and other environmental cues that act as circadian hooks . The subjects were allowed to set their own sleep schedule which ended up deviating from the typical 24-hour cycle. This experiment has been done many times, but in this case the scientists measured the blood levels of growth hormone and followed when the pituitary gland released the hormone. They found the peak levels of hormone released during sleep decreased significantly . The first slow wave sleep (SWS) period of the night was shorter and the first REM period happened sooner.
For more muscle
mass - see Creatine
For more stamina - see Energy
Anti-aging - see Longevity
For better blood sugar control - Diabetes
For better sex - there are many herbal supplements mentioned at libido web page or see Passion Rx below, a powerful sex booster with ashwagandha , catuaba, cnidium monnieri, coleus forskohlii, horny goat weed, maca, mucuna pruriens, muira puama, passion flower, pfaffia paniculata, rhodiola, shilajit, tribulus terrestris, tongkat ali, but no yohimbe.
For better vision - see Eyesight herbal formula.
For cautious hormone replacement, see DHEA and pregnenolone - tiny doses of 1 or 2 mg may benefit some people