Adaptations to Physical Activity PDF

9/13/2023 Physical Activity DEFINED: ANY BODILY MOVEMENT PRODUCED BY SKELETAL MUSCLE CONTRACTION THAT RESULTS IN A SUBSTANTIAL INCREASE IN ENERGY EXPENDITURE (ABOVE REE). INCREASE IN ENERGY EXPENDITURE MUST BE SIGNIFICANT ENOUGH TO ELICIT HE...

9/13/2023 Physical Activity DEFINED: ANY BODILY MOVEMENT PRODUCED BY SKELETAL MUSCLE CONTRACTION THAT RESULTS IN A SUBSTANTIAL INCREASE IN ENERGY EXPENDITURE (ABOVE REE). INCREASE IN ENERGY EXPENDITURE MUST BE SIGNIFICANT ENOUGH TO ELICIT HEALTH BENEFITS 1 ATP (Adenosine Tri-Phosphate) is the immediate energy source used for muscle contraction. A P P P PHOSPHATES HELD BY HIGH ENERGY BONDS P A P P BOND BREAKS AND ENERGY IS RELEASED FOR EXERCISE. 2 3 1  9/13/2023 4 5 MUSCLE CONTRACTION   ATP DEMAND   O2 AT CELLULAR LEVEL  HEART RATE STROKE VOLUME  A-VO2 DIFFERENCE VO2 = HR X SV (A-VO2 DIFFERENCE) 6 2  9/13/2023 CARDIAC OUTPUT INCREASES CARDIAC OUTPUT = HR X SV 5 LITERS/MIN AT REST, 20-25 LITERS/MIN AT MAXIMAL HR MUSCLE PERFUSION INCREASES BLOOD VESSELS OF THE WORKING MUSCLE DILATE (VASODILATION) BLOOD VESSELS OF THE LESS ACTIVE MUSCLES AND ORGANS CONSTRICT (VASOCONSTRICTION) OXYGEN EXTRACTION (A-VO2 DIFFERENCE) INCREASES THREE TO FOUR FOLD! WHY DO THESE RESPONSES OCCUR? 7 RESPIRATORY RATE INCREASES SYMPATHETIC NERVOUS RESPONSE METABOLIC BYPRODUCTS INCREASE IN MINUTE VENTILATION TIDAL VOLUME X RESPIRATORY RATE INCREASE IN BLOOD PRESSURE INCREASE O2 EXCHANGE AT ALVEOLI WHY DO THESE RESPONSES OCCUR? 8 BLOOD PRESSURE SYSTOLIC BLOOD PRESSURE INCREASES DURING EXERCISE DUE TO AN INCREASE IN CARDIAC OUTPUT DIASTOLIC BLOOD PRESSURE SHOULD REMAIN THE SAME OR MAY SLIGHTLY DECREASE DUE TO VASODILATION OF THE VESSELS 9 3  9/13/2023 PHYSICAL CARDIAC CHANGES INCREASED LEFT VENTRICULAR WALL THICKNESS INCREASED LEFT VENTRICULAR CHAMBER SIZE INCREASED CONTRACTILITY WHAT AFFECT DO THESE CHANGES HAVE ON: STROKE VOLUME? Notice the RESTING HEART RATE? difference in HR HR DURING SUBMAXIMAL EXERCISE? 10 Blood vessels Respiratory Improves vascular flexibility Increased alveoli surface area Increase in EDRF Increased tidal volume Endothelium derived relation ventilation factor Increased during high intensity exercise Decreased at rest and during moderate exercise 11 INCREASED MITOCHONDRIA INCREASED CAPILLARY DENSITY INCREASED STORES OF GLYCOGEN INCREASED OXIDATIVE USE OF GLYCOGEN INCREASED STORES OF TRIGLYCERIDES INCREASED OXIDATION OF FATS 12 4  9/13/2023 SUBMAXIMAL EFFORT 13 LET’S DISCUSS! 14 15 5