Short & Long Term Effects of Exercise on the Energy Systems Unit 2 – Physiology of Fitness

Short – Term - Energy systems Aerobic systems working – able to produce enough O2 to meet body’s demands Start to exercise – O2 used up quickly to recycle ATP-ADP-ATP CV & Respiratory have to start to work harder to meet increase in demand for O2 This takes time............ ATP-PC system kicks in, doesn’t need O2 to produce energy Only lasts for 10-15 secs If exercise continues or intensity drops then......

Short-Term effects - Energy systems Lactic acid systems takes over Still doesn’t need O2 to produce energy Uses Carbohydrates to produce energy But without O2 also produces lactic acid If exercise continues or intensity lowers....... Back to Aerobic system There has been enough time for the CV and Respiratory systems to ‘up their game’ to get more O2 in

Long Term - Energy systems Increase in Aerobic & Anaerobic Enzymes Long term exercise increases the muscle’s ability to generate ATP More & bigger mitochondria = more aerobic enzymes that can recycle ATP Anaerobic enzymes control the breakdown of glucose Increased Use of Fat as Energy Source Body gets better at coping with exercise so exercise becomes less intense so use aerobic system more which is able to use fat as a fuel during low intensity exercise