Exercise Physiology Lecture 2024 PDF

DPT-413 Exercise Physiology course Exercise Physiology Monira I. Aldhahi Week 4 Dr. Monira Aldhahi- -2024 All Rights Reserved Copyright so ...

DPT-413 Exercise Physiology course Exercise Physiology Monira I. Aldhahi Week 4 Dr. Monira Aldhahi- -2024 All Rights Reserved Copyright so  Contents Measurement of Anaerobic Metabolism The Anaerobic Exercise Response Dr. Monira Aldhahi- 2024 -2021 All Rights Reserved  Objectives of this class Discuss the interaction between aerobic and anaerobic ATP production during exercise. Describe the energy continuum as it relates to varying durations of maximal maintainable exercise. List the major variables that are typically measured to describe the anaerobic response to exercise. Dr. Monira Aldhahi- Copyright -2024 All Rights Reserved Explain the illustration  Relative Contributions of the ATP-PC, LA, and O2 Energy Systems to Maximal Exercise Both anaerobic systems respond immediately but neither can sustain the high level of ATP production needed. The LA system contributes more than does the ATP-PC by approximately 10 seconds. Conversely, the aerobic energy system (O2) is incapable of meeting the immediate energy demands but contributes to a meaningful degree quickly. Gastin (2001). Time-Energy System Continuum  Time-Energy System Continuum 1. All three energy systems (ATP-PC, LA, O2) are involved in providing energy for all durations of exercise. 2. The ATP-PC system predominates in activities lasting 10 seconds or less. Since the ATP-PC system is involved primarily at the onset of longer activities 3. Anaerobic metabolism (ATP-PC and LA) predominates in supplying energy for exercises lasting between 1 and 2 minutes. 4. By 2 minutes of exercise, the O 2 system clearly dominates. The longer the duration, the more important it becomes.  Time Course for the Utilization of PC and ATP and the Accumulation of Lactate in Muscle and Veins Muscle levels of ATP are maintained relatively constant during high-intensity, short-duration exercise at the expense of PC. The greatest depletion of PC occurs at 20 seconds of exercise, with the result that ATP is maintained. From 20 to 180 seconds, the decline in PC and ATP is both gradual and parallel Muscle lactate levels rise sooner and higher than do venous levels owing to the diffusion time lag and dilution. Source : Modified from Gollnick and Hermansen (1973). Reprinted by permission of Williams & Wilkins  Measurement of Anaerobic Metabolism One approach describes changes in the chemical substances either used in alactic anaerobic metabolism or lactic anaerobic metabolism (lactate). – chemical analysis of muscle biopsy specimens – blood samples (lactate analyzer) The second approach quantifies the amount of work performed or the power generated during short-duration, high-intensity activity.  Lactate Analyzer The blood sample may be obtained by venipuncture or by finger or ear lobe prick. an analyzer that requires a minimal blood sample (a 25-μL capillary tube obtained by a finger prick)  Lactate levels The two most common unite used report the L-are – millimoles per liter (mmol·L−1, sometimes designated as mM) – milligrams per 100 mL of blood (mg·100 mL−1, sometimes designated as mg% or mg·dL−1). One mmol·L−1 is equal to 9 mg·100 mL−1. Resting levels of lactate of 1–2 mmol·L−1 Peak value =8 mmol· L−1 or 72 mg·100 mL−1 is usually taken to indicate that an individual has worked maximally. Peak values as high as 32 mmol·L−1 or 288 mg·100 mL−1 have been reported.  Tests of Anaerobic Power and Capacity Energy system capacity is the total amount of energy that can be produced by an energy system. Energy system power is the maximal amount of energy that can be produced per unit of time. Sources: Bouchard et al. (1982, 1991).  Tests of Anaerobic Power and Capacity (1) the total mechanical power generated during high-intensity, short-duration work; (2) the amount of mechanical work done in a specific period of time (3) the time required to perform a given amount of presumably anaerobic work Two such tests are commonly used in laboratory settings: the Wingate Anaerobic Test (WAnT) the Maragaria-Kalamen Stair Climb sees  Performance Tests of Fast And Slow Anaerobic Power  These maximal effort power tests that rely on maximal activation of the intramuscular ATP–PCr energy reserves evaluate the time rate of doing work (i.e., work accomplished per unit of time).  The following formula computes power output (P): P = (F *D) /T where  F: equals force generated,  D: equals distance through which the force moves,  T: equals exercise duration.  Watts represent a common expression of power  Often tests of short-term performance tests of maximal effort for 1 to 10 seconds reflect energy transfer of the immediate energy system,  Tests of Anaerobic Power and Capacity Laboratory settings: Two such tests are commonly used Wingate Anaerobic Test (WAnT) Maragaria-Kalamen Stair Climb (power = D(m)*F(BW)/T(sec) ooooh Maragaria-Kalamen Stair Climb  Activity 4 ( 5 min) Dr. Monira Aldhahi- -2023 All Rights Reserved Copyright  The Wingate Anaerobic Test (WAnT) Athletes may need values as high as 0.10 kg·kg−1 of body weight, but the most common value used (as in the example that follows) is 0.075 kg·kg−1 body weight (Vandewalle et al., 1987). The revolutions (rev) of the flywheel are counted per second during the test, and from the mammam available information three variables are determined.  Peak Power (PP) The maximum power (force times distance divided by time) exerted during very-short-duration (5 seconds or less) work. (PP=rev × 𝑑(𝑚) × 𝑓(𝑘𝑔) Mean Power (MP) The average power (force times distance Total divided by time)=exerted pedal revolutions 45.25. during short-duration Highest (typically 5-sec relative peak power 30 = 55.50 kgm·min−1·kg−1 = 9.07 W·kg−1. Meanseconds) work. relative power = 40.84 kgm·min−1·kg−1 = 6.67 W·kg−1. Fatigue Fatigue index = Index (FI%) 1− (lowest 5 sec Percentage divided by highest 5 sec) × 100 = 46.34%. of peak power drop-off during high-intensity, short-duration work.  Field Tests No field tests are available to estimate the ATP- PC used or the lactate produced during exercise. Sport-specific tests are available, but two types of activities are commonly used: – vertical jump tests – Run testing  Vertical Jump Tests When the jump is performed on a force platform, actual power values can be calculated, and the test is considered a laboratory test. When the jump is performed as a field test on a normal surface, an estimate of work mmmm (force × distance), not power, is calculated. The height of the vertical jump and peak power as determined from force plate data has been shown to be highly correlated (r = 0.92). (Payne et al., 2000; Vandewalle et al., 1987).  Sprints, Shuttle, or Middle- distance RUN runners whose distance can be covered in a distinct time range (depending somewhat on age, sex, and training status) can be used as field tests of anaerobic metabolism (Cheetham et al., 1986; Thomas et al., 2002).  dashes of 40, 50, or 60 yd or m will take approximately 4–15 seconds and can be used as an indication of alactic anaerobic power and/or capacity.  Longer runs, probably between 200 and 800 m (or 220 and 880 yd) and lasting 30–120 seconds, can be used as an indication of lactic anaerobic power and capacity.  Factors Affecting Anaerobic Exercise Performance 1. Specific training: – training for brief, all-out exercise enhances the glycolytic system’s capacity to generate energy. 2.Buffering of acid metabolites: Anaerobic training might enhance short-term energy transfer by increasing the body’s buffering capacity(alkaline reserve). 3.Motivation: Individuals ability to “push” beyond the discomforts of fatiguing exercise accomplish more anaerobic work  Factors Affecting Anaerobic Exercise Performance 1. Specific training: – training for brief, all-out exercise enhances the glycolytic system’s capacity to generate energy. 2.Buffering of acid metabolites: Anaerobic training might enhance short-term energy transfer by increasing the body’s buffering capacity(alkaline reserve). 3.Motivation: Individuals ability to “push” beyond the discomforts of fatiguing exercise accomplish more anaerobic work  The Anaerobic Exercise Response 1. Oxygen Deficit and Excess Postexercise Oxygen Consumption  Oxygen Deficit and Excess Postexercise Oxygen Consumption A. a moderate submaximal bout The oxygen requirement for this exercise is 1.4 L·min −1. The individual has a VO2MAX of 2.5 L·min−1. Notice, there is an initial lag during which the oxygen supplied and utilized is below the oxygen requirement for providing energy. This difference between the oxygen required during exercise and the oxygen supplied and utilized is called the oxygen deficit.  Oxygen Deficit and Excess Postexercise Oxygen Consumption B. supramaximal exercise during heavy or supramaximal exercise, both the O 2 deficit and the EPOC are large. The heavier the exercise, the more the reliance on anaerobic glycolysis. (EPOC) is Oxygen consumption during recovery that is above normal resting values.  Factors appear to be responsible for EPOC a. Restoration of ATP-PC stores called the half-life restoration of ATP-PC. Full recovery requires 2–8 minutes b. Restoration of oxygen stores- Replenishment probably occurs completely within 2–3 minutes c. Elevated cardiorespiratory function d. Elevated hormonal levels e. Elevated body temperature (account for 60-70) f. Lactate removal g. Energy substrate shift from CHO to fat  Reference Exercise Physiology for Health, Fitness, and Performance by Sharon A.Plowman and Dr. Denise L. Smith PhD (Jan 26, 2010).Ch. 2 ,3(pp63-67). 3rd ed Gastin, P. B.: Energy system interaction and relative contribution during maximal exercise. Sports Medicine. 31(10):725–741 (2001). Bouchard, C., A. W. Taylor, J. A. Simoneau, & S. Dulac: Testing anaerobic power and capacity. In J. D. MacDougall, H. A. Wenger, & H. J. Green (eds.): Physiological Testing of the Elite Athlete. Hamilton, ON: Canadian Association of Sport Sciences Mutual Press Limited, 61–73 (1982). Vandewalle, H., G. Pérès, & H. Monod: Standard anaerobic exercise tests. Sports Medicine. 4:268–289 (1987). Payne, N., N. Gledhill, P. T. Katmarzyk, V. K. Jamnik, & P. J. Keir: Canadian musculoskeletal fitness norms. Canadian Journal of Applied Physiology. 25(6):430–442 (2000).  Lecture 3-4: Practical session Activity 1: Blood pressure measurement at different position Activity 2: Blood pressure measurement During isometric exercise Activity 3: Vertical jump Activity 4: – Wingate Anaerobic Test (WAnT) – Maragaria-Kalamen Stair Climb Equipment: Stopwatch , A sphygmomanometer , staircase, timer, Mate  Reference Exercise Physiology for Health, Fitness, and Performance by Sharon A.Plowman and Dr. Denise L. Smith PhD (Jan 26, 2010).Ch. 2 ,3(pp63-67). 3rd ed