Lecture 23: Effect of Exercise on Skeletal Muscle Office hours: Tuesday and Thursday 1-2pm in Gittings 108 or by appointment Extra office hours posted on D2L Claudia Stanescu, Ph.D.Objectives: pg. 317, sec. 10.7 1. List and describe the effects of exercise training on muscle. 2. Define muscle hypertrophy and muscle atrophy.Basic principle of exercise and response of muscle: Muscle will change in response to the stresses it encounters. Adaptations: 1) Increased capillary density 2) Increased mitochondrial density 3) Increased cross sectional area Exercise effects on muscleIncreased capillary density capillaries Before exercise After exercise Green H, et al (1998) Regulation of fiber size, oxidative potential and capillarisation in human muscle by resistance exercise. Am J Physiol. 276 R591-R596.Increase mitochondria density Aerobic exercise Broskey NT . Skeletal muscle mitochondria in the elderly:. J Clin Endocrin Metab, 99: 1852-1861, May 2014MRI shows increased cross sectional area (CSA) with resistance training Increased cross sectional area Coronal Axial Quadriceps VL Quadriceps VL Skeletal muscle hypertrophy and structure and function of skeletal muscle fibres in male body builders. J Physiol , 2006 , vol. 570 no. 3 611-627With training each muscle fiber increases in diameter increased # of myofibrils More sarcomeres in parallel = more cross bridges = more force Muscle hypertrophy and atrophy Training hypertrophy Detraining atrophyChanges after strength vs. endurance training hypertrophy capillary density # mitochondria hypertrophy capillary density # mitochondriaSuggested Learning Activities • Create a table listing the training adaptations that occur with endurance vs. strength
View Full Document
Unlocking...