Resistance Training Physiology

more than performance and aesthetics

it impacts locomotor organ and metabolic organ, “when you run out of muscle you die” no more stores of amino acids to help with recovery

resistance training outcomes

lower total and abdominal adiposity, lower weight and adiposity gain, healthier levels of MetS components and lower incidence of MetS, lower risk of developing HTN, lower insulin resistance, lower chronic inflammation, lower all cause mortality by 15%, cardiovascular disease mortality by 19%, and cancer mortality by 14%

adaptations to resistance training

maintains muscle mass and strength (prevents sarcopenia, frailty, and metabolic consequences)

sarcopenia: muscle atrophy, loss of function of skeletal muscle (associated with mitochondrial dysfunction)

mitochondrial biogenesis, function, RT causes mitochondrial biogenesis and also increase in mitochondrial function and function in muscle, RT prevents and reverses mitochondrial dysfunction (aging), sarcopenia, and glucose regulation/insulin sensitivity

maintains bone mineral density, prevents osteopenia and osteoporosis, falls, and fractures, LV hypertrophy in cardiac muscle (product of pressure load, sarcomere in parallel, increased chamber size (also with RT but a small amount, volume load, sarcomere in series)

maintenance of muscle cells, size, and type II motor units (muscle mass, strength, speed, power, quality of life (as we age we lose type II muscle fibers and less reinnervation of type I fibers. type II becomes type I, but we also just lose muscle fibers but exercise can prevent this

glucose and insulin adaptation to RT

glucose regulation, insulin sensitivity, acute exercise increases acute insulin-dependent and -independent glucose uptake, chronic exercise improves insulin-dependent and -independent glucose regulation, this happens for both aerobic and RT but the difference is the type of muscle contraction (RT or aerobic)

key in preventing, managing, reversing diabetes and insulin resistance (exercise that include the most musculature), squat and leg-press vs leg extension, main adaptations also increase GLUT4

more muscle mass, more ability for glucose regulation and insulin sensitivity (hypertrophy and muscle mass), skeletal muscle is the primary tissue contributing to glucose uptake (~80% of whole body glucose uptake), muscle mass influences the body’s ability to regulate blood glucose levels, low muscle mass increases the risk of insulin resistance, increased muscle mass is associated greater insulin sensitivity (may even reduce the risk of development of T2D), each 10% increase in skeletal muscle index (the ratio of total skeletal muscle mass to total body weight) associated with 11% relative reduction in insulin resistance, 12% relative reduction in pre-diabetes prevalence

older adults RT

acute disease of inactivity leads to sarcopenia more (numerous periods of inactivity compounded), RT can rebound (recover) some of the muscle loss,

the lower the muscle mass, and the lower the muscle strength = drastically increasing all-cause mortality risk

youth RT

it is appropriate and has positive effects, it does not stunt growth unless you have a fracture on the growth plate, just supervise it to be safe, don’t go too heavy but learn to lift safely and with good posture, and do both