<prompt> Immediate source of energy is -Corps cycleHMPATPTCA cycle  <response>: Ans. is c i.e., ATP o There are three energy systems to provide energy for muscular activities.Immediate energy system : Energy is provided by stored ATP and creatine phosphate.Anaerobic glycolytic system lactic acid system : Energy is generated by utilization of glucose or glycogen by anaerobic glycolysis. This energy is also generated early.Aerobic or oxidative system : Energy is generated by utilization of glucoseglycogen, and fatty acids through oxidative pathways, e.g. TCA cycle.o These three energy systems operate as a continuum: each system is always functioning, even at rest,o What varies is the relative contribution each system makes to total ATP production at any given time. Immediate energy systemAnerobic gly colytic systemOxidative aerobic sy stemSubstratesATP, creatine phosphateGlucose or glycogenGlucose or glycogen, fatty acidsEnergy productionVery fastFastSlowPeak at0-30 sec.20-180 sec.3 minLimiting factorDepletion of CrP, ATPLactic acid accumulationGlycogen depletionActivity examplePowerlifting weight lifting, short sprints Jumping, throwingLonger sprints Middle distance team sports Ball games Soccer, rugbyEndurance events Team sports Bail games Soccer, field hockey 