Exercise Testing and Prescription Lab
Metabolic Calculation Lab
Use Appendix D, lecture materials, and the conversions below to help you complete this lab. This lab is for
purposes of practicing metabolic calculations related to estimating oxygen consumption, energy expenditure
and weight loss, and calculating workloads for a given MET level. It should compliment the Exercise Testing
and Prescription lecture. Remember to record and convert all knows first before trying to solve a metabolic
problem.
USEFUL CONVERSIONS
Resting Metabolic Rate (RMR) = 1 met = 3.5 ml O2/kg body wt/min = 1 kcal/kg/hr
1 Liter O2 = 5 kcal = 2153 kgm = 15,575 ft-lbs.
1 kgm = 9.807 joules 1 kg = 2.2lbs
1 mph = 26.8 meters/min
1 watt = 6.1 kgm/min
DERIVATIONS OF THE FICK EQUATION
VO2(ml O2/min) = Q(L blood/min) * AVO2 diff(ml O2/L blood)
VO2(ml O2/min) = HR(beats/min) * SV(L blood/beat) * AVO2 diff(ml O2/L blood)
VO2(ml O2/min) = HR(beats/min) * SV(L blood/beat) * (CaO2(ml O2/L blood) – CvO2(ml O2/L blood))
VO2(ml O2/min) = HR(beats/min) * SV(L blood/beat) * ((1.34(ml O2/g Hb) * [Hb](g Hb/100ml blood) * SaO2(% O2 sat.) * 10) –
(1.34(ml O2/g Hb) * [Hb](g Hb/100 ml blood) *SvO2(% O2 sat.) *10))
note: multiplying by 10 in the calculation of blood O2 content converts ml O2/100 ml blood to ml O2/L blood the unit on
the “10” in the above equation is: (ml O2/liter of blood/ml O2/100 ml blood)
REGRESSION EQUATIONS FOR ESTIMATING VO2 MAX FROM TIME ON TREADMILL
BRUCE PROTOCOL VO2(ml/kg/min) = 14.8 - 1.379(TIME)(min) + .451 (TIME2)(min) - .012 (TIME3)(min)
BALKE PROTOCOL VO2(ml/kg/min) = 1.444(TIME)(min) + 14.99
NAUGHTON PROTOCOL VO2(ml/kg/min) = 1.61(TIME)(min) + 3.6
EQUATIONS INVOLVING RELATIVE MEASURES OF O2 CONSUMPTION
EI (mets) = VO2(ml 02/min) /body wt(kg) / 3.5(ml/kg/min/MET)
EI (kcal.min) = EI(mets) * body wt(kg) * .0175(kcal/kg/min/MET)
GENERAL EQUATION FOR SPIROMETRY CALCULATION OF VO2
VO2(ml O2/min) = (VI (ml O2/min STPD) * FIO2) – (VE(ml O2/min STPD) *FEO2)
Q = cardiac output
AVO2diff = difference in volume of oxygen between arterial and venous blood
VO2 = maximum oxygen consumption
HR = heart rate
SV = stroke volume
EI = exercise intensity
[Hb] = concentration of hemoglobin
CaO2 = content (volume) of oxygen in arterial blood
VI = volume of inspired air
VE = volume of expired air
CvO2 = content (volume) of oxygen in venous blood
SaO2 = saturation (% expressed as a decimal) of arterial blood with oxygen
SvO2 = saturation (% expressed as a decimal) of venous blood with oxygen
FEO2 = fractional concentration (% expressed as a decimal) of oxygen in expired air
FIO2 = fractional concentration (% expressed as a decimal) of oxygen in inspired air
Name
Metabolic Calculations Lab– Physiotherapy Spring 13 (worth 25 of 100 points)
You must show all work to get full credit.
1. An individual exercises 25 minutes on the Monarch bike at 2.5 kg and 50 rpm, 20 minutes on the treadmill
(jogging) at 5.5 mph and 4 % grade, and 40 minutes on the Elliptical at 8.2 METS. He weighs 180 pounds.
Determine his total caloric expenditure for this workout.
2. A pulmonary patient has started training with you in your rehabilitation program and has an exercise
prescription to work 45 minutes at 6 METS 5 days per week. The client weighs 205 pounds. Calculate the
following:
a. The treadmill grade for a speed of 2.5 mph.
b. The Watts for an arm ergometer.
c. Total caloric expenditure per week.
3. What speed does a person need to jog on a treadmill at 0% grade if this person is to work at 13.5 METs?
4. Calculate the MET level of stepping up and down on an 12 inch step at 24, 4cycle steps per minute.
5. A person who needs to exercise at approximately 8 METs is going on a business trip and will only be able to
use the hotel hall steps, which are approximately 7 inches (0.20 meters). What step rate (per minute) should he
use?
6. A post bypass patient who weighs 195 lbs is entering your cardiac rehabilitation program and is participating in a study
concerning hemodynamic responses of cardiac patients to exercise. During his exercise sessions, he is to undergo invasive
hemodynamic monitoring that will facilitate the determination of cardiac output, stroke volume.
a. Calculate the speed at which you would set a horizontal treadmill to elicit a workload of 6.5 METS.
b. Calculate the % grade you would use to elicit the 6.0 MET workload if the belt speed was 2.7 mph.
c. Calculate the resistance that you would set one the Monarch® bike at 60 RPM to elicit a 7.0 MET
workload.
The following questions 7 -13 are based on the case study below.
CLIENT:
Male Age – 47
Height – 72 in.
MEDICAL HISTORY:
Total Cholesterol 223
Triglycerides
101
LDL
148
HDL
34
Glucose
126
Weight – 215 lbs
%Fat – 25
High Blood Pressure
MEDICATIONS:
Capoten, Pepsid, Metaprolol
GXT: (see attached ECG) Maximum Time on Bruce Protocol: 10:00
PREVIOUS ACTIVITY LEVEL:
Seldom does any type of cardiovascular exercise for a significant period of time
Plays golf (walks) 4 times per week (18 holes)
7. What is the client’s Maximum Oxygen Consumption?
8. Calculate the grade for a treadmill workout at 65% VO2max and 4.5 mph (walking).
9. Calculate the resistance for a cycle workout at 75% VO2max and 60 rpm.
10. Calculate the caloric expenditure of the above cycle workout if it lasted for 50 minutes.
11. Calculate the caloric expenditure per week if the this client exercises for 50 minutes on the bike 2
times per week (#10) and walks on the treadmill for 40 minutes at the above intensity (#8) 3 times
per week.
12. How many weeks would it take him to loose 8 lbs if his resting metabolic rate is 1,350 kcals/day
and he is eating about 1,250 kcals/day. Use only his exercise program from question number 11 to
help estimate exercise energy expenditure.
14. Calculate the equivalent workload (necessary) on a treadmill for a woman weighing 75 kg and is cycling at 240 Watts. She plans on jogging about 6.5 mph on the treadmill.