lecture 5-6 Flashcards
Physiological demands of sport: considerations
Considerations Duration of the event Rest periods Rotations/substitution Closed or open environment Environmental conditions
Physiological demands of sport- team sport
- Time motion analysis
Repeated sprints
Endurance
Physiological demands of sport- individual sport
Individual demands
○ Power lifting
○ Tennis
○ Running – speed or endurance
how does ATP contract a muscle
ATP is the energy currency of the body regardless of the activity undertaken Power or endurance It is all about muscle contraction Energy is released when a phosphate molecule is cleaved from ATP to form ADP + Pi + Energy
how is ATP replenished
ATP is recycled ADP + Pi + energy = ATP But where does this energy come from? Via breakdown of macronutrients in the food we eat Carbohydrate Fat Protein
what are the 3 main pathways to replenish ATP
- ATP-PCr
Lactic acid system
Aerobic energy system
ATP-PCr system
PCr splits releasing energy which can then be used to recycle ATP
Like ATP, PCr is also in limited supply
~300-600g
Enough stored for 3-15 s of high intensity exercise
Thus is the main source of energy in activities such as sprinting
Lactic Energy System
Anaerobic glycolysis Does not require oxygen Break down of CHO to produce energy for ATP production The by-product of this process is Lactate lasting 30-60 s
Aerobic Energy System
Requires Oxygen to ‘burn’ fuel to produce ATP
Is the most economical energy system producing large amounts ATP,
although it is not as rapid as the anaerobic pathways
What limits the energy system?
- Fuel availability Oxygen availability Removal of waste products Cardiac output Mitochondria Buffering capacity
Adaptation to Anaerobic training
Muscle fibre type changes Increased levels of anaerobic substrates Enzymatic changes that enhance glycolysis Increased capacity to generate high levels of Lactate
Aerobic training methods
- Continuous aerobic training
Fartlek
Interval
Usually >30 min at an intensity below the LT
In athletes, the duration is generally greater than the performance time
○ Exceptions may be marathons or prolonged team games
During these sessions there is no significant accumulation of Lactic acid
measuring energy systems
- VO2max
Beep test
Yo-Yo
Timed run (1600m – 5000m)
What is VO2max?
The highest rate at which oxygen can be taken up and utilised by the body during severe exercise
What are the Rate Limiting
Factors of VO2max?
Cardiac Output - Improved with training Oxygen Delivery - Hbmass increased with training Oxygen Extraction - Increased capillary and mitochondrial function Metabolic waste removal?
Strength
The amount of force a muscle group can exert against a resistance in one maximal effort