Muscle Adaptation to Exercise PDF (Dar Al Uloom University)

C o ll e g e o f Muscle Adaptation M e d ic n i e to Exercise – ‫ك‬ ‫ل‬ ‫ية‬ ‫ا‬ ‫ل‬ Dr Moizuddin Khan ‫ط‬ ‫ب‬ C o ll Objectives e g 1. Strength, power, and endurance of muscles e o 2. Effect of athletic training on muscles and muscle performan...

C o ll e g e o f Muscle Adaptation M e d ic n i e to Exercise – ‫ك‬ ‫ل‬ ‫ية‬ ‫ا‬ ‫ل‬ Dr Moizuddin Khan ‫ط‬ ‫ب‬ C o ll Objectives e g 1. Strength, power, and endurance of muscles e o 2. Effect of athletic training on muscles and muscle performance, Muscle f M hypertrophy e 3.d Fast-twitch and slow-twitch muscle fibers ic 4.i Respiration in exercise, Oxygen consumption and pulmonary ventilation in n e exercise – 5. ‫ك‬ Effect of training on vo2 max ‫ل‬ 6. Cardiovascular system in exercise ‫ية‬ 7.‫ا‬ Work output, oxygen consumption, and cardiac output during exercise ‫ل‬ 8. ‫ط‬ Effect of training on heart hypertrophy and on cardiac output ‫ب‬ 9. Role of stroke volume and heart rate in increasing the cardiac output 11/20/2022 2 10. Body heat in exercise & heatstroke  Strength, Power, & Endurance of Muscles Muscles Strength can be define as the amount of force a muscle can produce. Maximal contractile force is influences by the size of the Loading… muscles (3 -4 kg/cm2). dicine – ‫كلية الطب‬ 11/20/2022 3 C o ll Strength, Power, & Endurance of Muscles e g o e Muscles Power is the amount of work that the f M e muscle performs in period of time ( kg-m/min). d ic i Ability to generate force quickly( combination of n e – strength & speed) ‫ك‬ ‫ل‬ ‫ية‬ Performance is limited without power ‫ا‬ ‫ل‬ ‫ط‬ ‫ب‬  Strength, Power, & Endurance of Muscles Muscles Endurance: Ability of muscles to sustain repeated contractions against a resistance for period of time. Loading… It depends on energy stored (glycogen) in the muscle. dicine – ‫كلية الطب‬ Types of Muscles Endurance: 1. Dynamic endurance: is defined as a muscle’s ability to contract and relax repeatedly. 2. Static endurance: is a muscles ability to remain contracted for a long period. C o ll e Physiological Effects of Strength Training g e o f Increases the following: M e Muscle mass and size of muscle fibers d ic i Utilization and coordination of motor units n e – Strength of tendons, ligaments, and bones ‫ك‬ ‫ ل‬ Storage of fuel in and blood supply to muscles ‫ية‬ ‫ا‬ Improvements in blood fat levels and biochemical ‫ل‬ ‫ط‬ processes ‫ب‬ 11/20/2022 6  Benefits of Muscular Strength and Endurance Improved performance of physical activities Prevention of injury Improved body composition dicine – ‫كلية الطب‬ Enhanced self-image and quality of life Improved muscle and bone health with aging Prevention and management of chronic disease 11/20/2022 7 C o Effect of Training on Muscles and Muscle ll e Performance g e o Maximal Resistance Training: f M 6 maximal muscle e d ic contractions X sets 3 days X i n e one week increase in muscle – ‫ك‬ strength, without muscle ‫ل‬ ‫ية‬ fatigue. ‫ا‬ ‫ل‬ BUT ‫ط‬ ‫ب‬ Muscles function under no Approximate effect of optimal resistive exercise training on increase in muscle strength over a training period of 10 weeks. ‫كلية الطب – ‪dicine‬‬ ‫‪11/20/2022‬‬ ‫‪9‬‬ C o ll Muscle Hypertrophy e g e With training muscles hypertrophied 30- 60 % o M f Due to increase: The diameter of the muscle fibers with e d some increase in number of fibers. ic i n e – ‫ك‬ ‫ل‬ ‫ية‬ ‫ا‬ ‫ل‬ ‫ط‬ ‫ب‬  What are the Changes in the hypertrophied muscle fiber? There is increase in the following: Both the aerobic & anaerobic metabolisms Myofibrils dicine – ‫كلية الطب‬ Loading… 120 % in mitochondrial enzymes ATP and phosphocreatine 50 % increase in stored glycogen 75 -100 % increase in stored triglyceride. The efficiency of the oxidative metabolic system 11/20/2022 11 C o ll g e Muscle Fibers e o f 1. Slow-twitch fibers M Fatigue resistant e d Don’t contract as rapidly and forcefully as fast twitch ic i fibers n e Rely primarily on oxidative energy system – ‫ك‬ 2. Fast-twitch fibers ‫ل‬ Contract rapidly and forcefully ‫ية‬ Fatigue more quickly than slow-twitch fibers ‫ا‬ ‫ل‬ Rely more on non-oxidative energy system ‫ط‬ ‫ب‬ 11/20/2022 12  Slow-Twitch vs Fast-Twitch Muscle Fibers Slow-twitch muscle Fast-twitch muscle For prolonged muscle for forceful and rapid activity dicine – ‫كلية الطب‬ contraction. e.g. soleus muscle in the e.g. gastrocnemius muscle lower leg muscle for used for jumping standing. achieves maximal power in Provide endurance, very short periods of time prolonged strength of 11/20/2022 13 contraction minutes to hours. C o ll Respiration In Exercise e g Oxygen consumption & pulmonary ventilation in e o f exercise increase about 20-fold between the resting state M e and maximal intensity. d ic i n e – ‫ك‬ ‫ل‬ ‫ية‬ ‫ا‬ ‫ل‬ ‫ط‬ ‫ب‬ Effect of exercise on oxygen consumption and ventilatory rate. (Redrawn from Gray JS: Pulmonary Ventilation and It Physiological Regulation. Springfield, Ill: Charles C Thomas, 11/20/2022 1950.) 14  Cardiovascular System in Exercise Work Output, Oxygen Consumption, and Cardiac Output During Exercise All are directly related to one another, muscle work dicine – ‫كلية الطب‬ output increases oxygen consumption, and increased oxygen consumption in turn dilates the muscle blood vessels, thus increasing venous return and cardiac output. C o ll e Cardiovascular System in Exercise g e o Effect of Training on Heart Hypertrophy and on f M e Cardiac Output (COP): d ic Training increase COP about 40 % greater than i n e untrained persons So, – ‫ك‬ heart chambers of marathoners enlarge about 40 ‫ل‬ ‫ية‬ percent in contrast to non trained. ‫ا‬ ‫ل‬ ‫ط‬ Heart size of marathoner larger than normal person. ‫ب‬  Cardiovascular System in Exercise The cardiac output increases from its resting level of about 5 L/min to 30 L/min. The stroke volume increases from 105 to 162 milliliters, an increase of about 50 percent dicine – ‫كلية الطب‬ Whereas the heart rate increases from 50 to 185 beats/min, an increase of 270 percent. The heart rate increase a greater proportion of the increase in cardiac output than does the increase in stroke volume why ? 11/20/2022 17 C o ll e g e o f M e d ic i n e – ‫ك‬ ‫ل‬ ‫ية‬ ‫ا‬ ‫ل‬ Approximate stroke volume output and heart rate at different levels ‫ط‬ ‫ب‬ of cardiac output in a marathon athlete.  Body Heat In Exercise Almost all the energy released by the body's dicine – ‫كلية الطب‬ metabolism converted into body heat. Remainder converted into  What will happen if sweating mechanism cannot eliminate the heat dicine – ‫كلية الطب‬ ???? 11/20/2022 20 C o ll e g e o f M e d ic i n e – ‫ك‬ ‫ل‬ ‫ية‬ ‫ا‬ ‫ل‬ ‫ط‬ ‫ب‬ 11/20/2022 21  Heatstroke During endurance training body temperature rises 37° to 40°C. Hot and humid conditions body temperature rise to 41° to 42°C High temperature is destructive (-ev)to tissue cells mainly (brain cells) dicine – ‫الطب‬ ‫كلية‬ Symptoms: Body weakness, exhaustion, headache, dizziness, nausea (disgust), sweating, confusion, uncontrolled gait, collapse, and unconsciousness and may lead to death C o ll e Treatment of Heatstroke g e The most practical way : o f M Remove all clothing e d ic Maintain a spray of cool i n water on all surfaces of e – the body or continually ‫ك‬ ‫ل‬ sponge the body. ‫ية‬ ‫ا‬ ‫ل‬ Blow air over the body ‫ط‬ ‫ب‬ with a fan. Physicians prefer total  References Text Book Of Physiology by Guyton & Hall, 11th edition Review of Medical Physiology by Ganong, 24th edition dicine – ‫كلية الطب‬