Unit 9: Anaerobic Performance Flashcards
Why is the yield of ATP through anaerobic energy turnover important for children
their activities involve bursts of energy expenditure
-the energy needs of children can not always be met by the O2 transport system and the oxidative properties of the working skeletal muscles
What does anaerobic performance depend on
local characteristics of a skeletal muscle or muscle group
What are the three components of anaerobic performance
Short term
intermediate
long term
Instantaneous muscular engagements
characterized by an almost 100% anaerobiosis
-in a 3 second contraction, the anaerobic system meets nearly 100 of energy needs
For how long does the anaerobic system contribute to maximal exercise
few seconds to about 3 min
What % of ATP in a 90 sec max contraction comes from the anaerobic system
50%
-other 50% aerobic contribution
What are the 4 primary energy sources that a child relies on
- ATP stored in the resting muscle
- Rapid phosphorylation of ADP to ATP through the creatine kinase enzyme pathway and the phosphocreatine pool
- Anaerobic glycolysis from glycogen to lactate
- Aerobic energy turnover using fatty acids, glucose, and glycogen as sources, together with oxygen
What is the goal of all energy pathways
to produce ATP to support muscular contraction in the form of ADP + P + heat
Use of ATP storage
-First and Fastest system (immediate source)
-Used in first 3 seconds of exercise
Use of ATP and Creatine system
-second pathway
-quickly creates ATP to support muscle contrcation
Glycolytic pathways
Converts glycogen, fatty acid, or glucose through more complex steps in metabolic pathways using O2
-more complicated processes take longer to turnover ATP
How does the complexity and speed change across the different primary energy sources
increases in complexity and decreases in speed down the list of energy sources
Determinants of anaerobic performance
related to body size (fat-free mass and muscle mass)
-age-associated and sex-associated variation more related to muscle mass differences than other factors
What are the 10 Anaerobic performance tests
- Margaria Step-running test
- Vertical jump-Sargent test
- Vertical Jump-force platform
- Isokinetic single joint test
- Force-velocity cycling test
- Quebec 10-second and 90-second cycling test
- Wingate Anaerobic test
- Isokinetic cycling test
- Sprinting-motorized treadmill
- Sprinting-nonmotorized treadmill
Margaria Step-Running Test
-First introduced in 1966, this test assesses peak mechanical power of a person who runs up the stairs at max speed
-Power (Kgm/s) = m(kg) x height (m) / t (sec)
-start 20 ft back go steps 3-6-9
Advantages of the margaria step-running test
easy to administer
can be preformed in a school or gym
Disadvantages of the margaria step-running test
-Performance is dependent on the skill of the participant
-participants may need to practice the skill several times to become proficient
-step-running requires many muscle groups, can’t isolate and measure just one
Vertical Jump-Sargent Test
-First test to ever yield reliable information on short term maximal muscle performance
-participant crouches momentarily, swings arms and jumps as high as possible
-measured variable is the net vertical elevation (highest point reached minus standing)
-multiplies by body mass is proportional to the power generated at takeoff
Vertical jump-Sargent test advantages
does not require equipment
can be performed at a school or gym
can be tested on both adults and children
Vertical jump-Sargent test disadvantages
-more children younger than 7-8 years old do not perform the test adequately (basic movement patterns for the vertical jump is not yet fully developed)
- Among children in the 4th-7th grades (9-13) about 40% do not perform the vertical jump with mature pattern
-This inability may limit the utility of the vertical jump as a measure of anaerobic power
Vertical jump-force platform
-participant takes off from a platform that electronically records forces
-by multiplying the vertical velocity at that instant, the mechanical power can be calculated
Advantages of vertical jump-force platform
quick to complete
Disadvantages of vertical jump-force platform
-The power produced by this test is only 50-60% of the peak power generated during the first 5-10 seconds of all out cycling
-Requires la equipment
Isokinetic single joint test
-uses isokinetic dynamometer
-participant will preform repeated maximal extensions or flexions across a single joint
-mechanical power is calculated as the product of the predetermined angular velocity and the measure of highest torque in each extension or flexion
-variables such as peak power, total work and fatigue index can be calculated
Force-Velocity Cycling Test
-test consists of several brief (5-7sec) cycling sprints on an ergometer
-each sprint is performed against a different braking force
-rationale for using several trials: mechanical power will be different at different braking forces
-only one force will yield actual peak power
Force velocity cycling test graph axis
x- force, kg
y - velocity, rpm and power, watt
Advantages of force-velocity cycling test
-the main asset of the force-velocity test is that it identifies the actual peak power
-peak power is less likely to occur with 1 single trial
Disadvantages of force-velocity cycling test
-can take around 45min to complete several sprints with adequate rest periods in between
Quebec 10-second test
-requires the participant to ride on a cycle ergometer all out for 10 seconds
-provides measure of total work output in 10-seconds
-has been used in children 9 years and older
-braking force set relative to body mass but is manually adjusted during the test so pedaling speed reaches about 10-16 m/sec
-reliability of test performance repeated within 7 days is above 0.95
Quebec 90-second test
-requires a ride to exhaustion
-has been used in boys and girls 10 years old & above
-braking forces set relative to body mass
-participant must pedal maximally for 90-seconds
-only one trial is given
-reproducibility of the test within 7days is 0.96
Wingate anaerobic test
-developed in the mid 1970s at the wingate institute in Israel
-most commonly used test for assessment of short term and medium term anaerobic performance
-30 sec cycling or arm cranking at max speed at a predetermined braking force
-force high enough to induce fatigue within several seconds
-power is calculated periodically or continuously (force x velocity)
-indices of performance are peak power (highest power achieved at any 3 sec period) and mean power (average power throughout 30-sec)
Disadvantage of the wingate test
lack of an easy way to determine the optimal braking force that would yield the highest possible power
Isokinetic Cycling test
requires a constant cycling velocity, where the changes in power are driven from the changes in the force exerted on the pedals
-test offers research opportunities regarding muscle contractibility and fatigability
Sprinting- Motorized treadmill
-The time that a person can keep sprinting on a motorized treadmill has been used as an index of intermediate-term anaerobic performance
-can also calculate the mechanical power or work performance based on body mass, running velocity, treadmill incline
-test based on several assumptions that have not been validated
-used with children and adults to estimate “total-body” anaerobic performance
-tends to evoke fear of falling causing early termination
-use harness to prevent falling
Sprinting - non-motorized treadmill
-Treadmill driven by the walking or running person
-participant tethered with a cable around waist
-horizontal cable connected to sensor to monitor horizontal traction forces and vertical displacement
-running velocity is determined by treadmill
-indices of performance include maximal velocity, peak power, mean power over a predetermined time, kinetic and potential energy, and the time to exhaustion
-little research on the sustainability of these treadmills with children
Recovery after anaerobic exercise in children
- Researchers have long had the impression that children recover faster than adults after a strenuous physical task
-Experiment on rate of recovery after wingate test boys (9-12 years) vs men (19-23 years) investigated % peak power recovery and H+ ion accumulation
Age differences in % peak power recovery
the time needed in between attempting another wingate test - and what % they could preform
-boys could perform 100% after 2 min recover while men could only perform 80% at that point
-10 min recovery for men to be able to perform 100%
