Transcript File
Fatigue & Recovery Causes of Fatigue • Depletion of energy stores • ATP CP stores • Glycogen stores • Lactic acid accumulation (and hydrogen ions) • Dehydration & reduced electrolyte concentrations • Increased muscle temperature • CNS Inhibition • Transmitter tiredness • Mental fatigue Depletion CP Stores • ATP CP system dominant between 0-6 secs • Much power is quickly developed by using this system • Creatine phosphate stored in muscle is rapidly depleted • Predominant energy system then becomes anaerobic glycolysis system • Between 10-20 secs. PC stored in muscles Depletion of Glycogen Stores • When the aerobic system is used continually during exercise glycogen stores are reduced • Fats then become the dominant fuel source which requires greater amounts of oxygen to break down & produce ATP & fatigue sets in • Have between 60-90 minutes of glycogen stored within the body during continuous activity Metabolic By Product Accumulation • As the rate of anaerobic glycolysis increases so does H+ and LA accumulation within the muscle fibres & in the blood • The presence of H+ and LA inhibits muscle contraction & fatigue occurs • H+ and LA cause the burning sensation in the muscles Dehydration (& reduced electrolyte concentration) • The body looses fluid through sweat • Sweat contains electrolytes, salts & water • Dehydration can cause fatigue to coordination, endurance & decision making Increased Muscle Temperature • Causes blood to be redirected away from the working muscles to the skin in an attempt to cool the body • Therefore oxygen supply to the working muscles is reduced • Increased body temperature can affect decision making CNS Inhibition • Central nervous system inhibition • When brain detects fatigue in the muscle it reduces the number and intensity of the messages to the muscle to decrease the contractions to prevent muscle damage Transmitter Tiredness • Fatigue causes the release of the chemical acetylcholine (Ach) to decrease • Acetylcholine is the chemical that travels across the neuromuscular synapse (the junction between the nerves and muscles) which assists in the stimulation of the muscle to contract • Less acetylcholine means the muscle contracts less Mental Fatigue • Tends to be associated with other forms of fatigue • Can make the athlete focus more on feeling tired rather than concentrating on their performance • In some instances boredom can also lead to mental fatigue Recovery Possibilities • • • • • • • • Active cool down Diet Fluid Ice Massage Hot/cold showers Water session Stretching Active Cool Down Recovery • Eg low intensity jogging • Undertaking low intensity active recovery increases speed of LA removal compared to passive recovery • Active recovery breaks down 50% blood LA in 10-15min. compared with 30 min. if passive) • Active recovery prevents venous pooling • Assists in reducing muscle soreness Diet (replenishment of fuel stores) • Following exercise athlete should consume high glycemic foods to replace glycogen quickly • Later continue with low glycemic foods • Foods high in protein can assist muscle regeneration Fluid Intake (rehydration) • Drink before, during and after training or competition • Sports drinks are good during because contain some carbohydrate and electrolytes • To increase desire to drink ensure it is flavoured, cool and contains some sodium Ice • Apply ice to bruised/sore/injured soft tissue area to prevent blood flow to area and reduce swelling • Ice also prevents inflammation (redness) and reduces pain • Ice vests can assist in reducing temperature to more normal levels Massage • Massage can assist blood supply to an area, decrease soreness and return muscle to normal length • However an injured area should not be massaged before 48-72 hours after the injury (apply ice) Hot/Cold Showers • Some athletes alternate hot and cold showers (eg 1 min hot, 1 min cold, 1 min hot etc) • This can stimulate the nervous and vascular activity to the muscles removing lactic acid and bringing nutrients to the muscles improving recovery Water Session • Eg swimming pool walking, swimming activities • This reduces the stress on the joints whilst allowing the athlete to move freely • Spas can also be used to massage and increase blood supply to the muscles Stretching • During cool down and in the days following competition & training • Prevents muscle stiffness, reduce soreness and returns muscle to it’s normal length