An increased metabolism or a high metabolism can be characterized by a seemingly inability to gain weight, nervousness, insomnia, and a high body temperature (less prone to feeling cold). For people with a high metabolism who regularly feel warm and break out into sweats, it is especially important to consume fluids throughout the day to keep the body temperature in check.In men, increased levels of testosterone can also lead to a heightened metabolic state. Testosterone is anabolic which means it contributes to muscle growth and bone development. Recent studies have suggested that men can raise their testosterone levels by 45% by abstaining from ejaculation for a period of seven days. Weightlifting and sprinting have been demonstrated as other natural methods for increasing one's testosterone.