Predicted VO2 max
Maximal Oxygen Consumption
What is it & Why measure it ?
• Greatest volume of oxygen that the body can
consume per unit time
• Regarded as “gold standard” of aerobic fitness
• Can be measured directly or estimated by use of
prediction tests
Direct Measurements
vs. Predictions
Direct Measurement
Used for:
 Research
 Development of regression
equations
Why:
 Accuracy
Predictions
Used for:
 At risk population
 Large field test
 Personal training
Why:
• Less Cost
– Equipment
– Training
– Of Running each Test
• Less Time
• Less Risk of Injury
– Because the test is
submaximal
Regression Equations
(Where do these prediction equations
come from?
• Large homogeneous sample populations
– College students, adults aged 30-45, >65
• Start with numerous variables
– e.g. Age, height, weight, sex, HR, lung capacity, MVC,
anaerobic capacity, sub max VO2, work load
• Determine which variable (or combination of
variables) best predicts VO2max
Regression Equations for
VO2max Prediction
1. Some prediction tests:

Are based on recovery HR after a specific submaximal
exercise test relates to VO2 max

Are related to speed in a running test compared to VO2
max

Include workload and HR
2. Equations usually differ based on gender and age
3. Equations can either predict to a relative or
absolute value
A Word of Caution in Predictions
• All prediction tests contain error known as the
standard error of estimate (SEE)
• SEE are expressed in measurement units used
for prediction or as a percentage
• Smaller SEE means the test is more useful
• Closely related to R2 value
Why Are Predictions
Based on HR?
• Data was gathered at several workloads
• HR plotted vs. VO2
• A line of best fit is extended through
predicted max HR for each person.
• Each person showed a very good R2 but
slopes of the lines differed for different
people based on fitness level
From HR to Regression Equations
• After recognizing the relationship between VO2
and HR
1.several people performed standardized exercise
regimens and recorded submax HR
2.These people also performed a true max test
3.Then Their VO2 max was plotted vs submax HR
(sometimes other variables were included) the
equation of this line is used to predict VO2 max
from the submax HR (the SEE is related to the
R2 value of this line).
Forestry Step Test
• Variables
– Recovery Heart Rate
– Step frequency
• Procedure
– Step up and down from a
chair for 5 min at a set
cadence (90 b/min or
22.5/min step rate)
– Measure HR from 15-30
seconds after completion
• Analysis
– Calculate relative VO2 max
from a regression equation
• Accuracy
– SEE is 12-15%
Astrand Cycle Test
•
Variables
–
–
–
–
•
Heart Rate
Load
Revolutions/Minute
Body Mass
Procedure
– Subject rides for 6 min at target
zone (table 14.2)-- 50rpm 2.5kg
women, 3.0kg men
– Load adjusted at 3 min if target
zone not likely to be achieved
•
Analysis
– Calculate power from load and
rpm
– Estimate absolute VO2 submax
and max using an equation
– Calculate Relative VO2 max