为什么肌肉锻炼很重要？

Resistance training or weight training is probably the main component of skeletal muscle fitness. the American College of Sports Medicine and the American Heart Association recommend that adults engage in resistance training at least twice a week, to improve muscle strength and endurance.

 why strength training is so important to our overall fitness,  first we need know about our body composition. Our body can basically be divided into two components. Fat mass consists of the body's fat store, while fat-free mass is a combination of non-fat tissue such as muscle, bone, internal organs, and so on. A significant part of fat-free mass is lean body mass, which is essentially muscle.

Muscle is metabolically active tissue. The importance of skeletal muscle as an organ cannot be overestimated, accounting for approximately 42% of human body mass and up to 93% of whole body metabolism depending upon level of physical activity in young adults. This means that it utilizes calories to work, repair, and refuel itself. Fat requires very few calories—it just kind of sits there. As we enter our mid to late twenties, we slowly start to lose muscle as part of the natural aging process. This means that the amount of calories we need each day starts to decrease, and it becomes easier to gain weight. (39, 90).  By engaging in regular strength training exercise, it is possible to decrease this loss of lean muscle tissue and even replace some that has been lost already.

 Strength training to increase lean body mass, decrease fat mass, and increase resting metabolic rate  (a measurement of the amount of calories burned per day), in younger and older adults. While strength training on its own typically does not lead to weight loss, its beneficial effects on body composition may make it easier to manage one's weight and ultimately reduce the risk of disease, by slowing the gain of fat—especially abdominal fat.

Another beneficial effect of resistance training pertains to bone health. In addition to weight bearing cardiovascular exercise, weight training has been shown to help fight osteoporosis.

Finally, in older populations, resistance training can help maintain the ability to perform functional tasks such as walking, rising from a chair, climbing stairs, and even carrying one's own groceries. An emerging area of research suggests that muscular strength and fitness may also be important to reducing the risk of chronic disease and mortality, but more research is needed.

Many people are intimidated by the idea of resistance training or are afraid of injury.

Reference

Haskell WL, Lee IM, Pate RR, et al. Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association. Med Sci Sports Exerc. 2007; 39:1423–34.

 Hunter GR, McCarthy JP, Bamman MM. Effects of resistance training on older adults. Sports Med. 2004; 34:329–48.

 Williams MA, Haskell WL, Ades PA, et al. Resistance exercise in individuals with and without cardiovascular disease: 2007 update: a scientific statement from the American Heart Association Council on Clinical Cardiology and Council on Nutrition, Physical Activity, and Metabolism. Circulation. 2007; 116:572–84.

 Schmitz KH, Hannan PJ, Stovitz SD, Bryan CJ, Warren M, Jensen MD. Strength training and adiposity in premenopausal women: strong, healthy, and empowered study. Am J Clin Nutr. 2007; 86:566–72.

  Engelke K, Kemmler W, Lauber D, Beeskow C, Pintag R, Kalender WA. Exercise maintains bone density at spine and hip EFOPS: a 3–year longitudinal study in early postmenopausal women. Osteoporos Int. 2006; 17:133–42.

 Gale CR, Martyn CN, Cooper C, Sayer AA. Grip strength, body composition, and mortality. Int J Epidemiol. 2007; 36:228–35.