There is a lot of research out there. Brief, High Intensity, exrcise will increase HGH as well as Test levels.
Researchers from Pennsylvania State University reported in the August 1996 issue of the "Journal of Applied Physiology" that subjects performing high-intensity resistance exercises, such as the bench press and the jump squat, experienced increased testosterone levels after they exercised.
Research on exercise and testosterone indicates that it’s more than going through the motions of weight lifting. What seems to optimally affect testosterone levels is to use the greatest volume of existing muscles to your maximum level of intensity within each exercise. That means using multiple muscle groups within each exercise to the point where your muscles fail – i.e., you cannot complete another repetition with acceptable form.
Eat Fat! A diet that includes about 30 percent fat, and not much less. Your body needs dietary fat to produce testosterone.
Sleep! Seven to eight hours of sleep a night and BLAMMO! Your testosterone levels are higher in the morning after a good night's sleep.
Do not overtrain – if you don't allow your body to recuperate adequately between training sessions -- your circulating testosterone levels can plunge by as much as 40 percent, according to a study at the University of North Carolina. The symptoms of overtraining are hard to miss: irritability, insomnia, muscle shrinkage, etc.
To avoid overtraining, make sure you sleep a full eight hours at night, and never stress the same muscles with weight-lifting movements two days in a row.
My diet is basically paleo now (been weaning myself off carbs). I know I need to up my fat intake though, so I am gonna get a load of almonds/walnuts/almond oil/almond butter/coconut today. I generally try to get as much fat into my diet as I can but I dont always have enough of it or enough sources of it in the kitchen.
Yep, sleep is a huge one, and I tend to sleep 7-8 and my body clock keeps my sleeping patterns regular.