Chapter 8 Flashcards
Fatigue (29 cards)
local fatigue
experienced in a muscle or group of muscles. usually during the performances
-muscles are heavy, tingling, cramping
general fatigue
occurs after a training session or an event
-muscles are weakened and psychologically fatigued
chronic fatigue
break down of the immune system. can last up to 7 years and is usually to do with overtraining
-leads to increased susceptibility to illness, persistent muscle soreness and lack of motivation
fatigue
refers to the inability to continue to exercise at a given intensity, can occur during maximal activity (lasts for a few seconds) or submaximal activity (last for a few hours)
refers to a decline in muscular power (concerned with intensity that can be sustained), strength and shortening
the onset and development of fatigue can depend on
intermittent/continuous activity
fast/slow twitch fibres (slow twitch are more likely to fatigue)
types of contractions (isometric cause fatigue)
intensity and duration (anaerobic work is more fatigue inducing)
various training adaptations and fitness levels
fatigue is either found in
central nervous system (central fatigue)
at muscle site (peripheral fatigue)
central fatigue
is the exercise induced inability to properly and fully contract or activate a muscle
associated with change in the CNS that results in the disruption of the message to the muscles
acts as a protective mechanism to protect our body’s from irreparable muscle damage
peripheral fatigue
originates from the muscle and ultimately results in a reduction of muscular power during exercise
this fatigue can occur because of
-fuel depletion
-accumulation of metabolic by-products (H+ ions, Pi, lactic acid)
-loss of muscle fibre activation (changes in Na+, K+ and Ca 2+)
most likely cause of fatigue in ATP-PC system
- accumulation of ADP and Pi
- depletion of ATP and PC
most likely cause of fatigue in aerobic glycolysis system
- accumulation of H+ ions
- due to working above LIP
most likely cause of fatigue in aerobic system
- depletion of blood glucose
- depletion of muscle/liver glycogen
- depletion of fats
- decreased motor unit recruitment (CNS related)
- elevated core temp, dehydration, increased sweat, loss of electrolytes, blood flow to skin
- not enough O2 is supplied to muscles
aerobic fatigue
refers to insufficient delivery of oxygen and nutrients to working muscles and reduced removal of waste products
overall fuel depletion
- involves using nearly all of a particular fuel such as PC
- there is usually 400g in the muscles but can be improved with training
- as a result the athlete must change fuel source or energy system that may not be preferred
- the slower the rate, the lower intensity the athlete can work at
example of overall fuel depletion
when PC runs out at 10 seconds, it relies on anaerobic/aerobic glycolysis which has slower rates meaning there will be a reduction in intensity
overall accumulation of metabolic by-products
- involves the accumulation of fatigue inducing by-products
- Pi can cause fatigue by interfering Ca2+ ions in muscular contractions thus reducing muscle output
- Lactic acid, H+ ions increase the acidity of the cell thus, interfering with enzymes and their role in muscle contractions meaning intensity must decrease
aerobic dehydration
- refers to a loss of bodily fluid which occurs during exercise due to us breathing out H2O and sweating
- decreased water in blood causes the blood volume to decrease and as a result the blood plasma reduction causes the blood to be thick meaning the heart has to work harder and less oxygen can be carried
- at VO2 max hydration declined but didn’t impact hugely. dehydration has more effect during prolonged activity in heat
- elevated core temp=activation of sweat
- water loss results in lower brain functioning; decrease in decision making
aerobic thermoregulation
- increased bodily temp
- linked to reduce blood flow to brain, limited supply of fuels and removal of waste (CO2)
- elevated skin temp=decrease in stroke volume and blood volume but increased HR
- thermoregulatory model states that the onset of fatigue will occur as core temperatures reach a critical 40 degrees
- fatigue occurs due to failure of CNS to supply constant impulses (enzymes begin to denature)
- above 40 degrees athletes collapse
neuromuscular fatigue
-as exercise intensity increases the release of the neurotransmitter (acetylcholine) decreases across the junction from nerve to muscle thus less electrical and muscle stimulation
if there is not enough time to resynthesise, acetyl choline muscles will contract less forcefully
eg in ultra marathons, hiking in hot country
loss of electrolytes
sodium and chloride, water balance and nerve impulses
potassium, conducts nerve pulses
calcium, crucial to synthesis of glycogen, contractions of muscles
magnesium, helps muscles to relax after contractions
delayed onset muscle soreness (DOMS)
occurs 24-48 hours after exercise result of micro tears in the muscles due to eccentric loading on muscles microtears are crucial to make our muscles stronger because as they repair, the muscles grow in size you can help to reduce DOMS by- -warming up/cooling down -staying hydrated -foam rolling -active recovery
overtraining
- refers to the decrease in performance despite training or prolonged attempts to improve performance
- overloading and not enough recovery time
- quite severe because it can have long term effects on performance
- recovery can take several weeks or months even
symptoms of over training include:
- elevated resting HR
- increased infections
- chronic fatigue
- changes on mood/apetite
- loss of motivation for training
- increased overuse injuries
- continued muscles soreness
- reduction in performance
- disturbed sleep patterns
recovery
-refers to the returning of the body to pre-exercise levels and ultimately reversing the effects of fatigue
-using recovery effectively can enhance training adaptations, and prepare athletes for the next training or event
-insufficient recovery will delay removal of fatigue factors and possible adaptations can lead to overtraining
eg ice baths, 10 degrees
-reduces inflammation
-causes vasoconstriction at periphery which causes vasodilation internally which aids the removal of metabolic by-products
passive recovery
involves the technique of sitting/standing after high intensity, short duration activity
key in replenishing CP stores, during passive recovery (this is done aerobically)
eg shot put, weightlifting, highjump etc
