Fatigue and Recovery Unit 3 AOS 2

Key Knowledge and skills the multi-factorial mechanisms (including fuel depletion, metabolic by-products and thermoregulation) associated with muscular fatigue as a result of varied exercise intensities and durations passive and active recovery methods to assist in returning the body to pre-exercise levels. Key Skills explain the role the energy systems play in enabling activities to occur as well as their contribution to active and passive recovery explain the multi-factorial mechanisms associated with fatigue during physical activity and sporting events resulting from the use of the three energy systems under varying conditions compare and contrast suitable recovery strategies used to counteract fatigue and promote optimal performance levels.

Factors affecting fatigue Intensity Duration Type of contraction (Isometric, isotonic) Training status Nutritional status Environmental conditions Type of activity Hydration levels

Fatigue Mechanism = Fuel Depletion ATP-PC System Fatigue Maximal Intensity Fatigue Mechanism = Fuel Depletion ATP stores = 2 seconds PC Stores = 10-12 seconds Result of Fatigue = Will need to slow down after PC stored depleted as they will need to use Anaerobic Glycolysis and Aerobic energy sytems to produce energy which have a slower rate Best Recovery = Passive Rest This is so aerobic system can restore the PC stores

ATP-PC System Fatigue Passive Rest – PC restoration rate Recovery Time PC Stores Restored 30 70% 60 75% 90 93% 120 95% 150 97% 180 98% 5-10 minutes 100% Full Recovery

Repeated efforts Explain why a tennis player can’t maintain the same intensity in a game of periods of high intensity and some rest.

Anaerobic glycolysis system fatigue Maximal intensity 85-95% Fatigue Mechanism = Accumulation of Metabolic by Products H+ (Hydrogen ions) Pi (Inorganic Phosphate) Result of Fatigue = Build of Hydrogen ions increases the acidity of the muscle. This slows the actions of the glycolytic enxymes and rate of glycogen breakdown. Therefore limiting anaerobic glycolysis system and causing athlete to slow down. Build up of ADP and inorganic phosphate and ADP reduces contraction force of muscles. Best Recovery = Active Reovery (5-10 min of similar activity @ 35-65% MHR) EPOC stage Increases rate of lactate removal. Maintain the rate of breathing and heart rate to keep blood flow elevated to break down metabolic by products Creates a muscle pump and reduces venous pooling.

Aerobic system fatigue Submaximal intensity Fatigue Mechanism = Fuel Depletion Result of Fatigue = Glycogen stores deplete after 90min+ there fore the body increasingly relies on fats to cerate energy. Due to the fact that fats take longer and more oxygen to break down the athlete can not longer sustain the intensity and will eventually slow down. When fats are depleted the body then turns to breaking down protein for energy. When this happens you are in big trouble! Best Recovery = High GI foods

How to stop fuel depletion Glucose ingestion Carbohydrate loading Whole body cooling Training Hydration Caffiene

Gareth finished an half ironman in 6 hours and 5 minutes Describe Gareth relationship of carbohydrates and fats as an energy source over 6 hours of continuous exercise. What effect would this have on performance and why?

Hitting the wall When the body has depleted its glycogen stores and relies on predominantly on fats is called “hitting the wall” https://www.youtube.com/watch?v=LKf1eTzmK14

Aerobic energy system fatigue Submaximal intensity Fatigue Mechanism = Elevated Body Temp Leading to Dehydration, blood flow away from muscles Result of Fatigue = Increased body temp leads to sweating. To cool the core blood is redirected away from the muscles to the skin to cool the body. This reduces oxygen supply to the muscle and therefore the aerobic energy decreases and the athlete has to slow down. Best recovery/prevention Hydration Before: 0.5-1L 2 hours before During: 150-250mL every 15 min After: 1.5L for every kg lost during event