Transcript Physiology of endurance presentation

Endurance
Endurance
Ability to work over time
More work in
equal time
More time doing
equal work
How can these variations be
measured between individuals?
Oxygen and Endurance
Exercise
Work
Muscle Contraction
glucose breakdown
ATP
Heart Rate
Oxygen to muscles
Blood Pressure
CO2 Production
Measures of
Endurance
Individual Variation
When work is equal, fit individuals can work longer
Fitness Level
Work
O2 Used
Time
More fit
Same
Less
More
Less fit
Same
More
Less
When time is equal, fit individuals do more work
Fitness Level
Time
O2 Used
Work
More fit
Same
Less
More
Less fit
Same
More
Less
Physiological Response to Exercise
Exercise = Work = Physiological Stress
Short –Term Changes
requires
ADAPTATION (or death)
Long–Term Changes
Blood Pressure
Heart Rate
Respiratory Rate
Respiratory Volume
Influences
Red Blood Cells
Blood Volume
Stroke Volume (heart increses in
size)
Capillary Density in muscle fibers
Slow Twitch:Fast Twitch Ratio
Mitochondria Density in muscle
fibers
Physiological Response to Exercise
Red Blood Cells
Blood Volume
Stroke Volume
Capillary Density
Cardiovascular System Adaptations
Improves O2 Delivery to Muscles
Slow Twitch:Fast Twitch Ratio
Mitochondria Density
Muscular System Adaptations
Improves Muscle Ability to
Use O2
Measuring Endurance
 Must measure work and
adaptation/response to
work
 Measuring work is easy
 Machines – treadmill, bike,
ergometer– measure work
output directly
 Real work – run, bike, swim
– measure work indirectly
by time
Measuring Endurance
 Must measure work and
adaptation/response to work
 Measuring response is harder
 Measure Cardiovascular
Response
 Changes in HR, BP, Respiration
 Short-term adaptations
influenced by long-term
adaptations
 Indirect data but easy to
measure
 Measure Gas Exchange
 CO2 production (our lab)
 O2 consumption
 Requires sophisticated
equipment/Harder to measure
Measuring Endurance – VO2 Max
 Volume of O2 consumed
at maximal heart rate
 Units are milliliters O2/kg
body weight/minute
 Allows comparisons
regardless of body size
 Influenced by
physiological adaptation
to exercise (ie. training)
Measuring Endurance – VO2 Max
 Direct Test
 Measures inhaled/exhaled
gas volumes
 Expensive and difficult
 Indirect Test
 Measures heart rate as
indicator of O2 consumed
 Cheap and easy
Measuring Endurance – VO2 Max
 Maximal Test
 Workload is increased to
maximal heart rate
 Difficult and/or dangerous
for non-trained individuals
Bleep Test
 Sub-maximal Test
 Workload is increased to
80% of maximal heart rate
 Maximal workload is
extrapolated to maximal
heart rate
Rockport Walk
Test
Measuring Endurance –
Rockport Walk Test
 Sub-maximal test for VO2 Max
 Walk (1) mile as fast as possible
 Measures workload
 Time to walk
 Measures response to workload
 Heart rate immediately on finish
 Equation predicts VO2 Max (ml/kg/min)
VO2 max (ml/kg/min) =
132.853 – 0.0769 (weight) – 0.3877 (age) + 6.3150 (sex) – 3.2649 (time) – 0.1565 (heart rate)
Measuring Endurance –
Population Norms