Fatigue and the Recovery Process Unit 1&2 Kevin Browne

Depletion of energy resources In order to exercise we must break down the energy stored in our body and turn it to ATP (This is what provides energy to our cells and working muscles) sources of energy come from 1)Phosphocreatine 2)Glucose 3)Glycogen

We only have enough phosphocreatine (CP) to last us 10 seconds of maximal exercise We then switch to glucose for energy production We have 15-20g of glucose in blood stream 345g glycogen in our muscles and 110g stored in our liver

glycogen into glucose/ or the skeletal muscles glycogen to glucose When out blood sugar is low the liver converts its stores of glycogen into glucose/ or the skeletal muscles glycogen to glucose Overall the glycogen gets turned into Glucose These stores only last 2 hours so once these are used up the body becomes fatigued

Effects of waste products Lactic acid is the main waste product of anaerobic glycolysis Blood always contains a small amount of lactic acid, but during high intensity this increases sharply decreasing ph – 6.4 or lower means that neural messages an not be sent and prevents exercise being carried out.

How Neuromuscular fatigue happens The muscle are not able to receive signals from the CNS that stimulate the muscle to contract or the muscle tissue is not able to function properly Signals an be affected by a lack of calcium ions being release and acetylcholine which prevents the nervous stimulation of the muscle tissue/motor unit

Recovery Process After any bout of Exercise, the body has to recover and return to its pre exercise state After exercise we need to breathe in extra amounts of oxygen to return to pre exercise state. This is also know as Excess post- exercise oxygen consumption (EPOC) but is also known as oxygen debt

Its occurs when we have been using the aerobic system- as a result energy has been produced by the anaerobic energy system which as we know produces lactic acid When we stop exercising out breathing rates remain high in order to get rid of the lactic acid and break it down to CO2 and H20 Restock ATP, PC and glycogen Pay back any O2 from haemoglobin and myoglobin

The 5 musts After hard exercise five events must take place before the muscle can operate again ATP must be replaced PC Stores must be restocked Lactic acid must be removed Myoglobin must be replenished with 02 Glycogen stores must be restocked

How it happens The replacement of ATP and PC 3 mins Removal of LA= 20mins Myoglobin and glycogen stores = 24-48hrs The fitter you are the faster the recovery, and the quicker the debt can be repaid The debt is paid in 2 stages known as Alactacid debt (fast component) Alactacid debt (slow component)

Alactacid Debt This process does not involve lactic acid The aerobic system is used to produce ATP to restock the PC Stores and ATP Stores in the body Around 50% occurs in 30 seconds and is fully recovered by 3 minutes The oxygen debt needed for this is between 2-3.5l of O2 the fitter you are the greater the debt (more oxygen) because you will have more stores to replenish but it will also be quicker

Lactacid debt This process takes much longer and can last minutes to hours depending on the intensity of the exercise Oxygen is needed to break down the lactic acid back to Pyruvate. (LA +O2 = Pyruvate) Pyruvate can then enter the aerobic system and leave as CO2 and water Lactic acid can also be converted back into glycogen and stored in the liver or muscle What can an active recovery do?