Lab 4 YMCA Bicycle Ergometer Functional Assessment

YMCA Bicycle Ergometer Functional Assessment Introduction Graded exercise tests, such as the YMCA bicycle ergometer protocol, provide essential information of functional aerobic capacity according to changes seen in heart rate and blood pressure response. We use submaximal testing to determine an appropriate exercise prescription according to the changes seen during a graded exercise test. Submaximal testing is valuable in that it is a low risk test and does not require subjects to exercise at maximal level, but with this comes the disadvantage of less accurate results when compared to maximal exercise testing (Mangum, 2013). There are four assumptions for submaximal exercise testing. One, individuals of the same age should have similar HRmax. Two, a steady state heart rate is obtained during each stage of the test. Three, a linear relationship exists between heart rate and VO2. And finally, mechanical efficiency is consistent for all subjects (Mangum, 2013). The purpose of this experiment was to assess functional aerobic capacity via the YMCA bicycle ergometer test. It was hypothesized that as the exercise workload increased over time, the subject’s heart rate and blood pressure would increase. Procedures Ambient conditions for the lab and demographics of the subject were recorded to begin the experiment. The Age Predicted Heart Rate Max was calculated using the equation: 207 – (0.69*Age) and 85% of the Age Predicted Heart Rate Max was also calculated to serve as a stopping point during the test. Pre-GXT data necessary to provide a comprehensive view of the subject’s cardiovascular risk such as, resting blood pressure, resting heart rate, health history, and the PAR-Q, was collected. Once the bicycle ergometer was calibrated, the subject received a complete explanation of the purpose of the procedure. The metronome was set to 100 clicks per minute and the subject was instructed to pedal so that one foot is in the “down” position with each click at 50 revolutions per minute through the entire test. The subject warmed-up for 2-3 minutes at an intensity of 0.5 kp. The clock was started to begin and the subject began to exercise for 3 minutes at an intensity of 0.5 kp. After 1 minute of exercise the heart rate was recorded. After the second minute, heart rate, blood pressure, and the Borg RPE rating was recorded. After the third minute, heart rate was recorded. Since the heart rate was within 6 bpm after the second and third minute, the subject advanced to the second stage. The intensity for the second stage increased to 1.5 kp. After 1 minute of exercise the heart rate was recorded. After the second minute, heart rate, blood pressure, and the Borg RPE rating was recorded. After the third minute, heart rate was recorded. Since the heart rate was not within 6 bpm after the second and third minute, the subject pedaled for an additional minute and a 6 bpm difference was achieved. The subject then advanced to the third stage. The intensity for the third stage increased to 2.0 kp. After 1 minute of exercise the heart rate was recorded. After the second minute, heart rate, blood pressure, and the Borg RPE rating was recorded. After the third minute, heart rate was recorded. Since the heart rate was within 6 bpm after the second and third minute, the subject advanced to the fourth stage. The intensity for the fourth stage increased to 2.5 kp. After 1 minute of exercise the heart rate was recorded. After the second minute, heart rate, blood pressure, and the Borg RPE rating was recorded. After the third minute, heart rate was recorded. Since the heart rate was within 6 bpm after the second and third minute, the subject advanced to the final cool down stage. The intensity for the cool down stage decreased to 0.5 kp. After 1 minute of exercise, the heart rate, blood pressure, and Borg RPE reading was taken and the subject was allowed to stop pedaling, completing the test. The same procedure was repeated for another subject. Once the data was gathered, each subject’s VO2max was calculated using the equation: VO2 ml/kg/min = [1.8 * (WR/BM)] + 3.5 + 3.5, where WR is the max work rate in kgm/min and BM is the body mass in kg. Results Table 1: YMCA Cycle Ergometer Data Sheet Subject: 1 Age: 31 Weight: 200 Resting BP: 120/84 mmHg Stage Stage 1 Resting HR: 78 bpm Age Predicted HRmax: 186 Time (min) 1 2 Heart Rate (bpm) 90 84 3 90 4 5 78 96 6 108/114 7 8 84 102 9 102 10 11 96 102 2.5 kp Cool Down 12 108 50 rpm/ 1 96 50 rpm/ 0.5 kp Stage 2 50 rpm/ 1.5 kp Stage 3 50 rpm/ 2.0 kp Stage 4 50 rpm/ 85% Age Predicted HRmax: 158 Blood Pressure (mmHg) RPE 120/86 7 122/88 11 120/84 12 126/88 13 128/82 7 0.5 kp Table 2: YMCA Cycle Ergometer Data Sheet Subject: 2 Age: 22 Weight: 200 Resting HR: 72 bpm Resting BP: 122/80 mmHg Age Predicted HRmax: 192 Heart Rate Blood Pressure RP (mmHg) E 1 2 (bpm) 96 96 124/80 6 3 102 4 5 96 108 126/84 8 6 108 7 8 102 114 128/84 11 9 96/102 10 11 102 108 128/86 14 12 120/120 1 102 126/80 7 Stage Time (min) Stage 1 50 rpm/ 0.5 kp Stage 2 50 rpm/ 1.5 kp Stage 3 50 rpm/ 2.0 kp Stage 4 50 rpm/ 2.5 kp Cool Down 50 rpm/ 0.5 kp 85% Age Predicted HRmax: 164 YMCA Maximum Physical Working Capacity Prediction 200 190 180 170 Heart Rate (bpm) 160 150 140 130 120 110 100 90 150 300 450 600 750 900 1050 1200 1350 1500 1650 Workrate (kgm/min) Figure 1: Heart Rate progression for subject 1 There was a significant heart rate response during stage 1 and stage 2 VO2max: VO2 ml/kg/min = [1.8 * (WR/BM)] + 3.5+ 3.5 = [1.8 * ( 1537 kgm/min / 91kg)] + 7.0 = 37.40 1800 1950 2100 YMCA Maximum Physical Working Capacity Prediction 200 190 180 170 Heart Rate (bpm) 160 150 140 130 120 110 100 90 150 300 450 600 750 900 1050 1200 1350 1500 1650 1800 Workrate (kgm/min) Figure 2: Heart rate progression for subject 2 There was a significant heart rate response during stage 3 and stage 4 VO2max: VO2 ml/kg/min = [1.8 * (WR/BM)] + 3.5+ 3.5 = [1.8 * (1350 kgm/min /91kg)] + 7.0 = 33.70 ml/kg/min Discussion 1950 2100 All experiments went as planned with no complications. Subject 1 had a more significant heart rate response during Stage 1 and 2 rather than during Stage 3 and 4. Because of this, we used the steady heart rate values during Stage 1 and 2 in order to predict maximal aerobic power for Subject 1 (see Figure 1). After calculating subject 1’s VO2max to be 37.40 ml/kg/min, it was determined that he was between the 20th and 30th percentile for maximal aerobic power. Subject 2 however, had a more significant heart rate response during Stage 3 and 4, therefore we used the steady heart rate values during Stage 3 and 4 to predict maximal aerobic power for Subject 2 (see Figure 2). After calculating subject 2’s VO2max to be 33.70 ml/kg/min, it was determined that he was below the 10th percentile for maximal aerobic power. According to our data, our hypothesis, as the exercise workload increased over time, the subject’s heart rate and blood pressure would increase, was neither supported nor rejected. For certain stages, there was a linear increase in heart rate, but for other stages the heart rate would increase then decrease, therefore we cannot completely reject our hypothesis (see table 1 and 2). However, we did see a significant increase in blood pressure as workload increased over time for both subjects (see table 1 and 2). Our skewed results could be because in most submaximal tests, heart rates and workloads are plotted and extrapolated to an estimated workload that has been associated with an average oxygen consumption. Also, during testing, the subject may not have been pedaling at the steady rate of 50 bpm, he may have slowed down when the workload was increased which in turn caused the drop in heart rate we see in some stages. Literature Cited Mangum, J. 2013. Resting and Exercise Measurement of Heart Rate and Blood Pressure. [Powerpoint slides].