Weight lifting increases muscle mass starting with the structure of muscles. Hormonal and physical stress increases the amount of sarcomeres and myofibrils in a given muscle, increasing the size of the fibers but not the quantity. The three types of muscle fibers are used in different kinds of activity. The fast fibers contract quickly because of how fast they can produce ATP. Aerobic fibers produce a lot of ATP efficiently and can store some oxygen to be used later. Anaerobic fibers use glycolysis to produce less ATP per glucose but at a faster rate. Weight lifting is fast and intense so it uses a lot of fast glycolysis fibers and is known to make muscles big. Endurance activities don’t do that. Instead they lead to improved blood circulation in order to get oxygen for contraction. Weight lifting also increases the amount of connective tissue supporting the muscle and strengthens the tendons. In order to increase muscle size, you have to lift at a higher weight than before. Too much too fast can tear muscle fibers and lead to soreness. Weight lifting also increases bone density, which can help combat the effects of osteoporosis. Muscles, tendons, and bones all work together to be strong enough to lift heavier things. With the right combination of intensity and regularity, weight training can give you not only a chiseled physique, but also a stronger, more resilient body.
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Weight lifting increases muscle mass starting with the structure of muscles. Hormonal and physical stress increases the amount of sarcomeres and myofibrils in a given muscle, increasing the size of the fibers but not the quantity. The three types of muscle fibers are used in different kinds of activity. The fast fibers contract quickly because of how fast they can produce ATP. Aerobic fibers produce a lot of ATP efficiently and can store some oxygen to be used later. Anaerobic fibers use glycolysis to produce less ATP per glucose but at a faster rate. Weight lifting is fast and intense so it uses a lot of fast glycolysis fibers and is known to make muscles big. Endurance activities don’t do that. Instead they lead to improved blood circulation in order to get oxygen for contraction. Weight lifting also increases the amount of connective tissue supporting the muscle and strengthens the tendons. In order to increase muscle size, you have to lift at a higher weight than before. Too much too fast can tear muscle fibers and lead to soreness. Weight lifting also increases bone density, which can help combat the effects of osteoporosis. Muscles, tendons, and bones all work together to be strong enough to lift heavier things. With the right combination of intensity and regularity, weight training can give you not only a chiseled physique, but also a stronger, more resilient body.