15
The fi nal assumption addresses the issue of
mechanical effi ciency. Oxygen uptake at any given
work rate can vary by approximately 15% between
different individuals. Therefore, individuals vary
in the amount of oxygen they require to perform a
certain exercise workload. Some individuals are more
effi cient at performing a given task than others. As a
result, the average oxygen consumption associated
with a given workload may vary signifi cantly from
one person to another. Thus, VO
2 max
predicted by
sub-maximal exercise tests tends to be overestimated
for those who are mechanically effi cient and
underestimated for those who are ineffi cient.
The point to remember is that sub-maximal exercise
testing, though not as precise as maximal exercise
testing, is not without advantages. For example, the
results of such testing can provide a fairly accurate
refl ection of an individual’s fi tness status without
the cost, risk, effort (on the part of the subject)
and time involved in max testing. If an individual is
given repeated sub-maximal exercise tests and that
person’s heart rate response to a fi xed workload is
found to decrease over time, it is reasonably safe to
conclude that the individual has made improvements
in aerobic (cardiorespiratory) fi tness, irrespective of
the accuracy of the VO
2 max
prediction.
Pretest Screening
Prior to any exercise test (maximal or sub-maximal),
participants should complete a brief health/medical
questionnaire, have their resting blood pressure and
heart rate measured, and provide an informed consent
form. The Physical Activity Readiness Questionnaire
(PAR-Q) is an example of a valid health/medical
questionnaire for screening individuals prior to
sub-maximal exercise testing. Canadian health and
fi tness practitioners have extensively (and quite
successfully) used the PAR-Q to determine whether
individuals should be given an exercise test. A”yes”
answer to any of the following seven questions
taken from the PAR-Q would disqualify a participant
from taking part in an exercise test until appropriate
medical clearance was obtained.
Physical Activity Readiness
Questionnaire (PAR-Q)
1. Has your doctor ever said you have a heart
condition and recommended only medically
supervised physical activity?
2. Do you have chest pain brought on by
physical activity?
3. Have you developed chest pain within the
past month?
4. Do you tend to lose consciousness or fall over as
a result of dizziness?
5. Do you have a bone or joint problem that could be
aggravated by the proposed physical activity?
6. Has a doctor ever recommended medication for
your blood pressure or a heart condition?
7. Are you aware, through your own experience
or a doctor’s advice, of any other physical
reason against your exercising without medical
supervision?
Nautilus
®
Sub-maximal Fit Test
The Nautilus
®
Fit Test is a program that estimates
maximal aerobic capacity based on heart-rate
response to sub-maximal exercise.
The Nautilus
®
branching protocol is a series of
3-minute stages of continuous exercise at
increasing intensity. The fi rst stage is a warm-up
at approximately 4 METs. The intensity of the
remaining stages is based on the heart rate response
to the warm-up. The test is designed to raise the
steady state heart rate of the subject to at least
THE NAUTILUS FIT TEST PROGRAM
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