PEAK 404 Lab Skills Page
1
PEAK 404
EXERCISE PHYSIOLOGY
LAB SKILLS
Basic Measurements, Units of Measure,
And Work/Power Calculations
1. Heart Rate at Rest (Palpation)
As will be discussed as this course progresses, heart rate (HR) can be a valuable
measure
used to indirectly estimate an individual’s current exercise effort level (%
.
VO2max) and assist in determining overall health status. Although palpation of HR is
a very basic concept and is quite routine, actual measurement of the pulse can be
difficult at times for certain individuals.
Skills Activity 1A.
Determine heart rate by palpating the pulse at the radial artery. Count the number of
beats within a 10 second (or 15 second) period. Count the first beat after you start
timing and the last beat just before time is elapsed. The pulse can be palpated by
placing two fingers over the radial artery on the wrist (thumb side). The Pulse can
also be palpated at the carotid artery in the neck just next to the laryngeal prominence
(Adam’s apple). Light pressure ONLY should be applied to determine the pulse
(heart rate can actually be altered if too much pressure is applied over the carotid
artery). Generate a “presentation table” that contains resting HR values for each
person in your group and their fitness ratings.
Table 1. Fitness ratings based on resting heart rate.
____________________________________________________________________
Resting HR
Fitness Rating
• < 60
excellent
• 60 - 69
good
• 70 - 79
average
• 80 - 89
fair
• > 90
poor
PEAK 404 Lab Skills Page
2
Table 2. Example presentation table of student fitness rating based on resting heart
rate.
____________________________________________________________________
Name
Resting HR
Fitness Rating
Joe Student
60
good
Josie Student
75
average
2. Blood Pressure at Rest (Auscultation)
Blood pressure is another very useful measure for overall health assessment. Resting
measures are frequently used to provide information concerning the baseline function
of the cardiovascular system and potential risk for cardiovascular disease and stroke.
Exercise measures are also useful for evaluating cardiovascular function during
different types of exercise (e.g., weightlifting vs. aerobic exercise).
Blood pressure literally is the pressure the blood exerts on the blood vessel wall from
the inside. It can be measured directly (intravascular) in almost any blood vessel.
However, it is more commonly and easily measured indirectly (noninvasive) at a
peripheral artery, usually the brachial artery in the arm. The method is referred to as
auscultation (sounds), sphygmomanometry or manometry, or the cuff method. In
general the procedure requires the technician to listen to the sounds within the artery
as blood flows through at varying cuff pressures. Initially, the cuff pressure is great
enough to completely occlude the artery so no blood passes through. As pressure in
the cuff is released, a point is reached at which time blood will be able to push
through the artery with each contraction of the left ventricle (systole). This causes a
vibration sound, which can be heard with the aid of a stethoscope. This sound is a
Korotcoff sound (phase 1). As the cuff pressure is further reduced, additional
Korotcoff sounds can be heard. The final two Korotcoff sounds of importance are
phase 4 (a muffling of the audible pulse) and phase 5 (complete disappearance of the
pulse sounds). Both these Korotcoff sounds represent the point at which blood flow
through the artery is becoming more streamlined and occurring even at cardiac
diastole. Phase 1, therefore, is used to indicate the systolic blood pressure (SBP),
and phase 4 and 5 are used to indicate diastolic blood pressure (DBP).
Skills Activity 2A.
Place the blood pressure cuff (bladder) around the left arm about one inch (2.5 cm)
above the crease of the elbow (antecubital fossa). The middle of the bladder should
be centered over the medial (inner) surface of the arm. The stethoscope diaphragm
should be placed over the brachial artery (anterior medial surface of elbow crease)
PEAK 404 Lab Skills Page
3
about one inch (2.5 cm) below the cuff. Often the pulse can be palpated to help
locate the position of the brachial artery. NOTE: the diaphragm should NOT be
under the cuff at all. Firm but light pressure should be applied to the diaphragm to
hold it in place.
Close off the bulb, and then inflate the cuff 30 to 40 mm Hg above the point where
the pulse cannot be heard. Gradually release the pressure via the bulb valve so that
the pressure decreases 2 - 3 mm Hg/s. Listen closely for pulse sounds. The point
where two consecutive pulses can be heard (sharp tap: phase 1) is the systolic
pressure. Continue to listen for the point when the sound muffles (phase 4) and then
completely disappears (phase 5). Record systolic and diastolic pressures in your
data table for each person in your group.
For general purposes, phase 5 is used for individuals over 12 years of age as the
diastolic blood pressure during rest, unless the pulse sounds do not disappear until 40
mm Hg. In this event, use phase 4 as the diastolic. For children, phase 4 is recorded
as the diastolic pressure.
NOTE: this procedure may take time to learn to perform successfully. Practice and
be patient.
Resting Blood Pressure Health/Fitness Rating:
• <120 / <80
very low risk
• 120 – 129 / 80 – 84
low risk
• 130 – 139 / 85 – 89
moderate risk
• 140 – 159 / 90 – 99
high risk
• 160 – 179 / 100 – 109
• ≥180 / ≥110
(optimal)
(normal, average)
(high normal)
(mild hypertension)
(moderate hypertension)
(severe hypertension)
3. Calculation of Work and Power During Cycle Ergometry
Movement increases energy expenditure above rest. Being able to measure energy
expenditure and power are crucial to a physiologist’s knowledge of an exerciser’s
physiologic demands and limitations. Some simple formulas are listed below along
with example calculations.
PEAK 404 Lab Skills Page
4
Work is the product of force times the distance it is applied.
Work = Force x Distance
or
W=FxD
One kilogram of force applied over a distance of 100 meters would equal 100 kg m
(kilogram meters) of work.
W = 1 kg x 100 m
W = 100 kg m
A device that measures work is called an ergometer. A stationary bike that allows the
measurement of work performed while riding is a cycle ergometer. A tensioned belt
applies a measured force against a flywheel. The flywheel travels a distance of 6
meters for every revolution of the pedals. A person pedaling 100 times (revolutions
of the pedal) will perform an amount of work equal to the force of the belt times the
distance the flywheel turns during the time they pedal.
Work = 1 kg x 6 meters/rev x 100 rev
Work = 600 kg m
Power is used to describe the amount of work performed per unit of time.
Power = Force x Distance
Time
or
Power = Work
Time
The rider of a cycle ergometer will pedal against a known resistance, with a particular
cadence (pedal revolutions/min), and for a designated period of time. When these
values are known, both work and power can be calculated.
Work = 1 kg x 6 meters/ rev x 100 rev/min x 5 minutes
Work = 3000 k gm
While
P = 1 kg x 6 meters/rev x 100 rev/min
P = 600 kg m/min
PEAK 404 Lab Skills Page
5
Conversion Factors allow one to move from one type of unit to another.
The unit for work is called a joule (1 kg m = 9.8 joules).
600 kg m x 9.8 joules / kg m = 5880 joules
The unit for power is called a Watt (1 Watt = 6.12 kg m/min)
600 kg m/min x 1 watt / 6.12 kg m/min =
98.0 Watts
Skills Activity 3A.
Calculate the work in kg m and joules and power in kg m/min and Watts for the
following situations:
1) Tension at 1.5 kg, pedaling cadence at 40 rev for 1 minute
2) Tension at 2.25 kg, pedaling cadence at 80 rpm for 3 minutes
3) Tension at 3.0 kg, pedaling cadence at 50 rpm for 5 minutes
4. Heart Rate and Blood Pressure Measurement During Exercise
Heart rate and blood pressure changes during exercise are the physiologist’s gauge of
how hard the exerciser is working, be it a normal response or an abnormal response.
The normal response can be used to indicate fitness while the abnormal response can
be a cue for the exerciser to seek medical advice. The skills of measuring these
physiologic responses are the physiologist’s “tools of the trade” and must therefore be
practiced routinely.
Skills Activity 4A.
Each group will have one subject perform cycle ergometry, while the other group
members will be responsible for data collection. Heart rate will be measured by
palpation and blood pressure will be determined by auscultation (as described in part
2 of this lab). Once the subject has been appropriately prepared (blood pressure cuff
placement), the subject will quietly sit on the Monark Cycle Ergometer for 3.0 min,
during which resting measures will be made during the last 15 seconds of each
minute, and then recorded. Next the subject will ride the cycle ergometer for
approximately 6.0 min, with increases in work rate occurring at the end of each
minute. Specifically, each subject maintains pedal cadence at 50 rpm. Exercise
begins with a resistance of 0.5 kg and increases of 0.5 kg increments up to 3.0 kg at
PEAK 404 Lab Skills Page
6
beginning of 6.0 min. Heart rate and BP measurements should be made during the
last minute of each stage. Recovery measurements should be made for 2 minutes of
post exercise cycling at 0 kg m and for 2 minutes of quiet rest. (1) Record the
stages, work rates, HR, and BP on the data table below. (2) Plot HR (dependent
variable – Y axis) vs. work rate (independent variable – X axis) on one line
graph and (3) plot both SBP and DBP (dependent) vs. work rate (independent)
on another line graph. Each graph should be on a single page and labeled
appropriately. Each should be titled, “Figure __ - Influence of ____ on ____.”
Be specific about the type of exercise used to influence a physiological function.
Although these skill activities are not graded, they will serve to give you practice in
the skills needed to be successful in this class. Practice them often, especially when
your group must wait to use equipment.
Rest Rest Rest
2
3
1
Ex
1
Ex
2
Ex
3
Ex
4
Ex
5
Ex
6
Rec
1
Work
Rate
HR
SBP
DBP
Compare your answers in part 3A to the following.
1.
2.
3.
W=360 kg m, W=3528 joules, P=360 kg m/min, P=59 Watts
W=3240 kg m, W=31752 joules, P=1080 kg m/min, P=176.5 Watts
W=4500 kg m, W=44100 joules, P=900 kg m/min, P=147 Watts
Rec
2
Rec
3
Rec
4