Phosphagen System Slides PDF

1   Stored ATP Cells contain a small quantity, so they must continually resynthesize it at its rate of use Provides ATP primarily for short‐term, high‐intensity activities (e.g., resistance training and sprinting) and is active at the start o...

1   Stored ATP Cells contain a small quantity, so they must continually resynthesize it at its rate of use Provides ATP primarily for short‐term, high‐intensity activities (e.g., resistance training and sprinting) and is active at the start of all exercise regardless of intensity Only 3‐5 sec @ maximal intensity 22 Fig. 2.4. Kenney et al. 2012. Physiology of Sport… Hum.Kin.   Phosphocreatine (PCr) CK is used to rapidly provide ATP by taking a phosphate (Pi) from PCr and adding it to ADP. Cells store ~4‐6x more PCr than ATP Muscles store enough PCr to last about 10 seconds at max intensity Phosphocreatine Creatine Kinase PCr + ADP Cr + ATP 33  4  Note that creatine kinase (CK) is a reversible reaction CK generates ATP during high‐intensity activity by taking a phosphate from PCr CK uses ATP to regenerate PCr in recovery from exercise Creatine Kinase PCr + ADP Cr + ATP High‐intensity exercise PCr + ADP Cr + ATP Recovery PCr + ADP Cr + ATP 4   ATP recovery utilizes oxidative phosphorylation in the electron transport chain (ETC) via the enzyme ATP synthase.  Recovery: 3‐5 minutes  PCr is restored by using ATP as a ATP synthase (in ETC) substrate in the creatine kinase rxn  Recovery: 8‐10 min Must recover your stored ATP first, however. PCr + Cr + ATP ADP Creatine Kinase 5   Why is the phosphagen system the preferred energy source at the start of exercise and for very high‐intensity activity? How long does it last?  Apply this information to different sports or events. Do these events have sufficient time for the phosphagens system to recover? Bioenergetically, what would it mean if your phosphagens system couldn’t recover?  Know the CK reaction in both recovery and high‐intensity exercise 6   Haff & Triplett. Essentials of Strength Training & Conditioning, 4th edition. Human Kinetics, 2016. 77