Predicting Endurance Performance

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Predicting Endurance Performance
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Maximal Oxygen Uptake

• Has been shown to be the single most important
  factor in predicting distance running success
  (and for other endurance events)
• Costill, D. 1967. The relationship between
  selected physiological variables and distance
  running performance. Journal of Sports Medicine
  and Physical Fitness, 761-66.
• Foster, C. 1983. VO2max and training indices as
  determinants of competitive running performance.
  Journal of Sports Sciences, 11338-44.
• Kenney, W. and J. Hodgson. 1985. Variables
  predictive of performance in elite
  middle-distance runners. British Journal of
  Sports Medicine, 19,207-209.

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Other Predictors

• Lactate/Ventilatory Threshold
• Exercise Economy

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Lactate Threshold

• Exercise intensity where blood lactic acid levels
  begin to accumulate above resting levels (gt 2
  mmol/L) or systematically increase
• Correlate with endurance performance
• Can provide an estimate of maximal steady state
  speed (2 miles to marathon) optimal training
  stimuli
• Can also be used to assess training adaptations
  (esp. in those with high VO2max values)

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Assessing Lactate Threshold

• Test specificity
• Protocol similar to max test, with small changes
  in intensity from stage to stage
• Blood samples obtained from an indwelling
  catheter
• Lactate in mmol.L-1 plotted against VO2 and the
  breakpoint is determined
• Often expressed as a percentage of VO2max

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Determining Lactate Threshold
Lactate Threshold
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Ventilatory Threshold

• Is used as a non-invasive estimate of lactate
  threshold
• Respiratory response to increased CO2 from
  buffering of lactic acid
• Related to fatigue and performance

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Determining theVentilatory Threshold
Ventilatory Threshold
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Exercise Economy

• Oxygen cost at a given work rate
• Determined by plotting oxygen uptake at several
  STEADY-STATE speeds

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Economy
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Predicting Endurance Success

• Ex distance running (10,000 m)
• Assess economy and VO2max, lactate/ventilatory
  threshold
• Use results to estimate maximal race pace

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Lactate Threshold
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Predicting Race Pace

• Determine speed at Lactate threshold
• Divide distance by speed (10,000m / 200 m/min)
• 50 min.
• Other factors
• Research specific to event
• Environmental factors
• Motivation
• Fuel storage
• Anaerobic contributions in shorter runs

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Velocity at VO2max (vVO2max)

• Speed at which an individual can run at VO2max
• Based on economy and VO2max
• Plot VO2 against several submaximal speeds and
  develop a line of best fit

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Predicted vVO2max
vVO2max
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Critical Power

• Based on the idea that athletes can maintain a
  specific submaximal power output for a long
  period of time without fatigue (Hill, 1993,
  Hughson et al., 1984, Kolbe et al., 1995)
• Critical power would be the power output that can
  be maintained indefinitely

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Critical Power and Performance

• Significant correlation between critical power
  and endurance performance lasting from 3 to 100
  minutes (r 0.67 0.85)

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Assessing Critical Power

• Series (5-7) of timed exercise trials to
  exhaustion over several days
• Length of time at a given running speed is
  plotted
• Critical power determined by the point at which
  power/time curve plateaus

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Critical Power
Critical Power
Adapted from Powers, SK and Howley, ET. Exercise
Physiology. McGraw Hill Boston. 2001. P.
393.
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Mixed-Endurance Assessment

• Test should last between 60 120 seconds
• Treadmill tests
• Speed
• Fitness level

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Anaerobic TM Testing

• Supramaximal (125 of aerobic capacity)
• Measure time spent at prescribed speed and grade
  (6 mph and 20 grade)
• Comparative scores
• College aged men 78.4 seconds (mixed)
• College aged women 36.8 seconds
  (power-endurance)