They're one of the most efficient and natural ways to help your body produce more testosterone by itself, which makes the both safe and sustainable. (fitnessandpower.com)
On the opposite side, if you are in a form of high intensive physical activity your body will be producing more testosterone in order to support your muscles and their demanding activity. (fitnessandpower.com)
Men produce more testosterone when they are around women who are having fertile cycles. (faith.org.uk)