Muscle growth is more difficult to achieve in older adults than younger adults because of biological aging, which leads to many metabolic changes detrimental to muscle growth; for instance, by diminishing growth hormone and testosterone levels. Some recent clinical studies have shown that low-dose HGH treatment for adults with HGH deficiency changes the body composition by increasing muscle mass, decreasing fat mass, increasing bone density and muscle strength, improves cardiovascular parameters, and affects the quality of life without significant side effects.[unreliable medical source?]
The general strategy adopted by most present-day competitive bodybuilders is to make muscle gains for most of the year (known as the "off-season") and, approximately 12–14 weeks from competition, lose a maximum of body fat (referred to as "cutting") while preserving as much muscular mass as possible. The bulking phase entails remaining in a net positive energy balance (calorie surplus). The amount of a surplus in which a person remains is based on the person's goals, as a bigger surplus and longer bulking phase will create more fat tissue. The surplus of calories relative to one's energy balance will ensure that muscles remain in a state of anabolism.
Samuel states that Tantrism is a contested concept. Tantra yoga may be described, according to Samuel, as practices in 9th to 10th century Buddhist and Hindu (Saiva, Shakti) texts, which included yogic practices with elaborate deity visualizations using geometrical arrays and drawings (mandala), fierce male and particularly female deities, transgressive life stage related rituals, extensive use of chakras and mantras, and sexual techniques, all aimed to help one's health, long life and liberation.