<Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (February 2008) (Learn how and when to remove this template message) </Td> </Tr> <P> The benefits of weight training include greater muscular strength, improved muscle tone and appearance, increased endurance and enhanced bone density . </P> <P> Many people take up weight training to improve their physical attractiveness . There is evidence that a body type consisting of broad shoulders and a narrow waist, attainable through strength training, is the most physically attractive male attribute according to women participating in the research . Most men can develop substantial muscles; most women lack the testosterone to do it, but they can develop a firm, "toned" (see below) physique, and they can increase their strength by the same proportion as that achieved by men (but usually from a significantly lower starting point). An individual's genetic make - up dictates the response to weight training stimuli to a significant extent, training cannot exceed a muscle's intrinsic genetically determined qualities, but clearly polymorphic expression of Myosin heavy chains is possible . </P> <P> Workouts elevate metabolism for up to 14 hours following 45 - minutes of vigorous exercise . </P>

Exercise training to improve muscular strength should be performed