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

2. 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 secs If exercise continues or intensity drops then......

3. 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

4. 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