Bioenergetics Intro - Slides & Notes PDF

1   bioenergetics: The conversion of macronutrients into biologically usable forms of energy.  energy: The ability to perform work.  The potential energy within the ATP molecules powers ALL of the cells’ energy‐ requiring processes...

1   bioenergetics: The conversion of macronutrients into biologically usable forms of energy.  energy: The ability to perform work.  The potential energy within the ATP molecules powers ALL of the cells’ energy‐ requiring processes  All other energy stores are used to replenish ATP by phosphorylation of ADP 22 Fig. 1.9. Haff et al. 2016. Essentials of Strength… Human Kinetics   Three basic energy systems exist in muscle cells to replenish ATP: Phosphagen (sarcoplasm) Glycolytic (sarcoplasm) Oxidative (mitochondria) 33 Fig. 6.3. McArdle et al. 2014. Exercise Physiology… LWW  Characteristics of the Various Energy Supply Systems ATP per Energy Oxygen Relative rate of Available Location ATP per second molecule of Capacity System necessary? substrate Phosphagen Sarcoplasm NO 10 1 100 days Tab. 2.3; Fig. 2.13. Kenney et al. 2012. 4 Physiology of Sport… Hum. Kin.   Exercise intensity determines the primary energy system utilized  Higher intensity – demands faster production of ATP  Lower intensity – can use slower, more efficient means of ATP production  At no time, during either exercise or rest, does any single energy system provide the complete supply of energy. Tab. 2.3. Baechle et al. 2008. 5 Essentials of Strength… Human Kinetics   This table assumes that you are maintaining that intensity and pacing yourself for the best possible time for a given event.  For example, you shouldn’t sprint the first lap of a mile and then walk the next 3 laps. This table assumes you are maintaining the same intensity.  Also note that the phosphagen system can last up to 15 seconds and does NOT run out after 6 sec Tab. 2.3. Baechle et al. 2008. 6 Essentials of Strength… Human Kinetics   The extent to which each of the three energy systems contributes to ATP production depends primarily on the intensity of muscular activity and secondarily on the duration.  At no time, during either exercise or rest, does any single energy system provide the complete supply of energy. 77  Primary Energy Systems Utilized by Different Sports 8 Tab. 5.1. Haff et al. 2016. Essentials of Strength… Human Kinetics   Know how the different energy systems rank in regards to speed of ATP production and efficiency of ATP production. Efficiency refers to the # of ATP produced per substrate used.  APPLY the bioenergetics information to different exercises and sporting events of varying intensities. 9   Haff & Triplett. Essentials of Strength Training & Conditioning, 4th edition. Human Kinetics, 2016.  Kenney, Wilmore, Costill. Physiology of Sport & Exercise, 6th edition. Human Kinetics, 2015.  McCardle, Katch, Katch. Exercise Physiology: Nutrition, Energy, and Human Performance, 8th edition. Wolters Kluwer Health, 2014. 10 10 Phosphagen system aka ATP‐PCr system Creatine Kinase reaction = PCr + ADP ‐‐> Cr + ATP Glucose (C6H12O6) + 6O2 ‐‐> 6CO2 + 6H2O 4 *Key Points of confusion* 1) This table represents the PRIMARY energy system being used during these time frames. It does NOT mean that it is the only system being used. 2) The INTENSITY of the exercise determines which energy system you are using (NOT the duration) 3) You do not transition between energy systems as you move to these different time frames (it depends on the Intensity) 4) An energy system does not simply “run out” and you move onto the next….it depends on the Intensity… 5) Note that the phosphagen system DOES NOT run out after 6 sec, but it can last to about 10‐15 sec of high intensity exercise. 5