Exercise Physiology Flashcards
At rest what are the needs of skeletal muscles
Low metabolic needs, 20-30% oxygen uptake
What are oxygen requirements of muscle mass at rest
75ml/min
What are oxygen requirements of muscle mass during severe exercise
300ml/min
Why are glucose anf fats mobilised for oxidation
To yield ATP for muscle contraction
Which systems undergo change in order to meet metabolic needs
- Cardiovascular system
- Respiratory system
- Endocrine system
How can the amount of work in a performance task be assessed
By measuring the increase in oxygen uptake compared to rest
What is VO2max
The measure of the maximum volume of oxygen that an athlete can use.
What si the single best measure of cardiovascular fitness
VO2max
What is isometric (static) exercise
Constant muscle length and increased tension
What is dynamic exercise
Rhythmic cycles of contraction and relaxation; change in muscle length
How does the body respond to isometric and dynamic exercise
Through adjustments to the cardiovascular system and respiratory system
What is moderate exercise
Steady state attained in 2-3 minutes, can talk comfortably
What is heavy exercise
Steady state not attained for 10-20 minutes, can talk but less comfortably
What is marathon pace
Heavy exercise
Where is the lactate threshold reached
During heavy exercise
What is severe exercise
‘Working on borrowed time’- fatigue is inevitable and highly predictable
Where is critical power/ speed
In severe exercise
What is extreme exercise
Maximum effort for 2 minutes or less
What are the two types of respiration
Aerobic and anaerobic
Which type of respiration is long term and happens during exercise such as swimming or cycling
Aerobic
Which type of respiration is short term and happens during exercise such as weight lifting or sprinting
Anaerobic
How does anaerobic respiration allow muscles to generate force in the absence of oxygen
The combined actions of ATP/ creatine phosphate and glycolysis
Why is anaerobic respiration less efficient
Lactic acid is produced
When is anaerobic respiration prevelant
During the early minutes of high-intensity exercise
How do muscles generate force during aerobic respiration
They use oxygen through oxidative phosphorylation
Which type of respiration yields more ATP
Aerobic
When is aerobic respiration the primary method of energy production
During endurance events
Which type of muscle fibres are in use during anaerobic exercise
Fast twitch muscle fibres
Describe the characteristics of fast twitch muscle fibres
- Large in diameter
- Light in colour (low myoglobin)
- Surrounded by few capillaries
- Relatively few mitochondria
- High glycogen content (have a ready supply of glucose for glycolysis)
Describe the characteristics of anaerobic exercise
- Sprinting, weight lifting
- Short duration, great intensity
- Creatine phosphate and glycogen from muscle fibres
- Fast-twitch muscle fibres: IIa/IIb
Describe the characterstics of slow twitch muscle fibres
- Red in colour (high myoglobin)
- Surrounded by many capillaries
- Numerous mitochondria
- Low glycogen content
- Also metabolise fatty acids and proteins- broken down into acetyl CoA that enters the Krebs cycle
Describe the features of aerobic exercise
- Long-distance running, swimming
- Prolonged but at lower intensity
- Fuels stored in muscle, adipose tissue and liver
- Major fuels used vary with the intesnsity and duration of exercise (glucose early, FFA later)
- Slow twitch muscle fibres
Which type of muscle fibres are used in aerobic exercise
Slow twitch muscle fibres