Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
FATIGUE |
A decline in muscle force, contraction rate and muscular power. The impairments must be reversible in recovery as to be distinct from damage |
|
FATIGUE MECHANISMS |
1. Fuel Depletion 2. Accumulation of metabolic bi-products 3. Thermoregulatory 4. Neuromuscular Factors
|
|
CENTRAL FATIGUE |
Mechanisms operating outside the muscles that inhabit activation and reduce force production. (Within the Central Nervous System, thought to prevent muscle damage) |
|
PERIPHERAL FATIGUE |
Mechanisms operating within the muscle that affect the ability of the muscle itself to produce force. |
|
TYPES/LEVELS OF FATIGUE |
1. LOCAL - in specific muscle groups 2. GENERAL - in all muscle groups 3. CHRONIC - unhealthy level of fatigue, caused by a breakdown of body's defences |
|
FATIGUE MECHANISM - FUEL DEPLETION |
- Intramuscular ATP - Phosphocreatine - Muscle Glycogen - Blood Glucose |
|
FATIGUE MECHANISM - NEUROMUSCULAR EVENTS |
- Decreased firing of the Central Nervous System (CNS) - Impaired Sodium and Potassium gradients |
|
FATIGUE MECHANISM - THERMOREGULATORY |
- Hyperthermia and Hypothermia - Increased rates of dehydration - Redistribution of blood to assist cooling |
|
METABOLIC BI-PRODUCTS IN ATP-PC SYSTEM DOMINANT EVENTS |
- Reduced force production - Increased Pi - slows Ca2+ release/uptake; slows contraction speed - Increased ADP - slows ATP breakdown and resynthesis |
|
METABOLIC BI-PRODUCTS IN ANAEROBIC GLYCOLYSIS SYSTEM DOMINANT EVENTS |
- Increased Lactic Acid Production and lactate levels - produced at 85% Max HR - Increased H+ ions - inhibit enzymes glycolysis; slows rate of energy systems; slows rate of ATP resynthesis; prevents myosin cross bridges from attaching with actin. -Pi is believed to be the largest contributor to the fatigue process in exercise of any duration. |
|
METABOLIC BI-PRODUCTS IN AEROBIC EXERCISE |
- Peripheral fatigue - less force - Increased lactate levels - Increased H+ ions - inhibit enzymes glycolysis, slows rate of energy system, slows ATP resynthesis. |
|
RESPONSES DEPEND ON |
- Type, Intensity and Duration - Fitness levels and mental state - Muscle Fibre usage and contractions - Bi-Product Production - Hydration Levels |
|
MUSCLE FIBRES - FAST TWITCH |
- Fast reaction time that relies on PC stores - These deplete quickly - Reduced oxygen supply in comparison to the aerobic slow twitch fibres |
|
MUSCLE FIBRES - SLOW TWITCH |
- High stores of glycogen and triglycerides help produce energy - Eventually reserves are depleted or the neuromuscular process breaks down. |
|
ISOTONIC MUSCLE CONTRACTIONS |
- Muscle length changes throughout a range of movement - Concentric = Muscle shortens - Eccentric = Muscle lengthens - E.g. sit-ups, throwing, sports |
|
ISOMETRIC MUSCLE CONTRACTIONS |
- No change in muscle length while force is developed. - Can cause in increase in blood pressure - E.g. Plank hold, wall sit |
|
ISOKINETIC MUSCLE CONTRACTIONS |
- High speed contraction through a full range of motions. - Needs specialist training equipment. |
|
FATIGUE IN ANAEROBIC ENERGY SYSTEMS |
- Depletions of ATP and then PC are the most common causes of fatigue in the ATP-PC system. - Fuel depletion does not cause fatigue during the anaerobic glycolysis system. |
|
FATIGUE IN AEROBIC ENERGY SYSTEM |
Depletion of glycogen stores, the fats. |
|
LACTATE INFLECTION POINT |
The last point of balance before lactate production exceeds lactate removal |