Tuesday and Wednesday Labs |
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| Wed 9 am trained & untrained | ||
| Wed 11:30 am trained & untrained | ||
| Wed 12:30 trained and untrained | ||
| Click here for sample graph (from Lindsey) | ||
It has also been shown that myocardial oxygen consumption ( MVO2) is highly correlated to the product of heart rate and systolic blood pressure. This number, called the Rate-Pressure Product (RPP) or Double Product, can be used effectively in the evaluation of a cardiac patient's response to exercise since the magnitude of this value is also related to the onset of angina pectoris caused by myocardial ischemia (Robinson, 1967). Of added interest is the effect of static exercise on this index. It has been shown that static contractions can al so increase the double product disproportionately and thereby increase the demands on the heart. The extent of this increase is dependent on the relative force of the contraction as well as the duration of the event, but not to the absolute tension produced or to the bulk (mass) of the muscle activated.
PURPOSE
The purpose of this lab is to measure the heart rate and blood pressure
response to static and dynamic exercise and relate these changes to the
stress upon the heart as indicated by the Rate-Pressure Product.
MATERIALS
1. bicycle ergometer
2. stethescope and sphygomanometer
3. hand grip dynamometer
4. data sheet
5. work clock
PROCEDURE
Data will be collected as follows on a trained and sedentary individual.
1. Adjust the seat of the ergometer to the appropriate height. Determine 35% and 70% of MVC using the handgrip dynamometer. Attach the BP cuff to the upper n on-dominant arm.
2. Obtain resting HR, Systolic and Diastolic BP.
3. Have the subject ride at a moderate workload (1-1.5 Kp/min for females and 2-2.5 Kp/min for males) at a rate of 50 rpm for a period of six (6) minutes. Record HR and BP (systolic only) on alternate minutes (ie: 2, 4, and 6 min).
4. Without interruption, at the beginning of the seventh minute have the subject remove the foot from the pedal on the same side as the BP is being taken and rest it on the foot support so that he/she now pedals one-legged at the same workload. Record HR and BP each minute for two (2) minutes of one-legged pedaling.
5. Now, without interruption, have the subject return to two-legged pedaling for three (3) minutes. Record HR and BP for each minute.
6. Next, without interruption, have the subject hold a 35% maximal voluntary contraction (MVC) on dynamometer the handgrip with the dominant hand for one (1) minute. Record the HR and BP at 30 sec and one minute of this stage.
7. Release the grip and continue to ride for another 4 minutes while maintaining the same workload. Record HR and BP at 2 and 4 min.
8. Next, repeat the static contraction of step #6 using the 70% MVC on the dominant hand for one (1) min. Record the HR and BP at 30 sec and one minute of this stage.
9. Finally, have the subject pedal at the same workload for six (6) additional min. Record HR and BP at 2, 4, & 6 min.
CALCULATIONS
Compute the RPP and MVO2 for each minute according to the following
formulas:
RPP = HR x SBP x 0.01
MVO2 ml/100gLV/min = (0.16 x RPP) - 6.0
1. MVO2 vs time for your groups subject
2. HR vs. time for your subject
3. SBP vs. time for your subject
4. MVO2 of trained untrained vs. time
5. HR of trained and untrained vs. time
6. SBP of trained and untrained vs. time
1. Review the data which shows the response of the MVO2 to
the two-legged dynamic exercise, the one-legged dynamic exercise, the 35%
MVC imposed on the dynamic exercise, and the 70% MVC imposed on the dynamic
exercise. What is the effect of an isometric contraction by even
a small muscle mass upon the work of the heart? Is the re a difference
in the work of the heart between the trained vs. untrained subjects.
Give an explanation for your answers.
2. On the assumption that the same work was being performed with one leg as with two, what effect does the amount of muscle mass recruited to perform a task have upon the work of the heart when the total work accomplished by the individual is the same?
3. Describe in detail the procedures to measure blood pressure.
If you use our text book to answer the question, make sure you provide
a reference.
CARDIOVASCULAR REPONSE TO ISOMETRIC EXERCISE IN AN ENDURANCE-TRAINED
SUBJECT DATASHEET
SUBJECT _______________________________ DATE _________________
WL ___ Kp/min HR b/min SBP mm Hg RPP MVO2 ml/100gLV/min
Rest _________ ___________ ________ ____________
Exercise
2 min _________ ____________ ________ ___________ _
4 min _________ ____________ ________ _____________
6 min _________ ____________ ________ _____________
One-legged
1 min _________ ____________ _________ ______________
2 min _________ _____________ _________ ______________
two-legged
1 min _________ _____________ _________ ______________
2 min _________ _____________ _________ ______________
3 min _________ _____________ _________ ______________
35% MVC
3 0 sec _________ _____________ _________ ______________
1 min _________ _____________ _________ ______________
Exercise
2 min _________ _____________ _________ _______________
4 min _________ _____________ _________ _______________
70% MVC
30 sec _________ _____________ _________ _______________
1 min _________ _____________ _________ _______________
Exercise
1 min _________ _____________ _________ ________________
2 min ___ ______ _____________ _________ ________________
3 min _________ _____________ _________ ________________
CARDIOVASCULAR RESPONSE TO ISOMETRIC EXERCISE
IN A SEDENTARY SUBJECT DATASHEET
SUBJECT _______________________________ DATE _________________
WL ___ Kp/min HR b/min SBP mm Hg RPP MVO2 ml/100gLV/min
Rest _________ ___________ ________ ____________
Exercise
2 min __ _______ ____________ ________ ____________
4 min _________ ____________ ________ _____________
6 min _________ ____________ ________ _____________
One-legged
1 min _________ ____________ _________ ______________
2 min _________ _____________ _________ ______________
two-legged
1 min _________ _____________ _________ ______________
2 min _________ _____________ _________ ______________
3 min _________ _____________ ________ _ ______________
35% MVC
30 sec _________ _____________ _________ ______________
1 min _________ _____________ _________ ______________
Exercise
2 min _________ _____________ _________ _______________
4 min _________ _____________ _________ _______________
70% MVC
30 sec _________ _____________ _________ _______________
1 min _________ _____________ _________ _______________
Exercise
2 min _________ _____________ _____ ____ ________________
4 min _________ _____________ _________ ________________
6 min _________ _____________ _________ ________________
Estimation of Myocardial Work
Table 1: Estimated work of the heart during cycling in a trained and
untrained subject by rate-pressure-product.
________________________________________________________________________
Untrained RPP Trained RPP
________________________________________________________________ ________
Two-leg (6 min)
One-leg (8 min)
35% MVC
70% MVC
Two-leg (20 min)
________________________________________________________________________