Lab Six: Maximal Exercise. Stephanie Smith. University of Otago. PHSE 203: Exercise Physiology. Due 5pm Monday, 9 th May 2011.

Transcription

1 Lab 6 PP4, S Smith, 1 LAB REPORT SIX Lab Six: Maximal Exercise Stephanie Smith University of Otago PHSE 203: Exercise Physiology Due 5pm Monday, 9 th May 2011 Lab Stream: PP4 smitsm31@suny.oneonta.edu

2 Lab 6 PP4, S Smith, 2 EXPERIMENT 1: COMPARISON OF WINGATE TESTS Introduction Purpose and Rationale This lab experiment introduces the measurement of anaerobic fitness or maximal power in short, explosive and high intensity movement. Aim Conduct 30 second Wingate tests on a large portion of the lab stream and deem the physiological and practical implications of the pattern of power outputs within and between people. Hypothesis The power output of females is less than the power output of males when completing a 30-second Wingate test. Methods Participant Table 1: Participant Details Participant Number Height (cm) Weight (kg) Sex Male Male Male Female Male Resting Heart Rate (beats/min) Resting Blood Pressure 130/65 122/50 135/65 118/60 125/70 Preferred Sport Hockey Hockey Cycling Netball The gym Fitness Status Average Average Trained Average Average

3 Lab 6 PP4, S Smith, 3 Females n=1; males n=4 (Age = 21 1; weight = kg 7.9; height = ; Resting Heart Rate = ; Resting Systolic Blood Pressure = ; Resting Diastolic Blood Pressure = ) Equipment This experiment was done on a Repco cycle ergometer. This air-braked ergometer that was connected to a computer along with ADInstruments LabChart software and PowerLab hardware allowed for the collection of data while the five participants cycled. A scale was used to measure the weight of the participants and a stadiometer was used to measure their heights. A blood pressure cuff, stethoscope, and sphygmomanometer were used to determine the participants resting blood pressures. Lastly, a heart rate monitor was used to measure the resting heart rate of the participants. Procedures 1. Group roles were organized. One person was in charge of the computer tasks including the start and stop of the 30 second test while keeping time. This person also wrote down the key measurements in table 2. Another person restrained the cycle ergometer to prevent it from moving or falling over. One person encouraged the participant and monitored the participant before, during and after the test. 2. The participant s resting variables including resting heart rate and blood pressure were taken and recorded. 3. The cycle ergometer was then adjusted specifically for the participant. 4. Once all of the jobs were assigned, resting variables were recorded, and the bike was adjusted, the participant then began to exercise. Before the 30 second test the participant warmed up, pedalling up to 60 rpm before engaging in the intense 30-s bout.

4 Lab 6 PP4, S Smith, 4 5. Once the participant finished the 30-s intense bout, he/she was able to do a warm down. * These procedures were done for all five of the participants. Data Analysis The LabChart Software on the computers used in this lab recorded and calculated most of the information needed. The one variable that had to be calculated by hand was the fatigue index. The equation for the fatigue index is as follows: Table 2: Raw Data from Wingate Tests Results Measurement Value Participant Number Peak Power (W) 1, , , ,291.2 Minimum Power (W) Mean Power (W) Time to Peak Power (s) Total Work (J) 24, , , , , Fatigue Index (W/s) Weight (kg) Relative Peak Power (W/kg)

5 Power Output (W) Lab 6 PP4, S Smith, 5 Discussion Question 1 The hypothesis was accepted; the power output of females was less than the power output of males when completing a 30-second Wingate test. Question per. Mov. Avg. (1) per. Mov. Avg. (213.17) 100 per. Mov. Avg. ( ) Time (s) Figure 1. Power output for the participants with the highest and lowest peak power, and the mean power for all five participants. This power (measured in Watts) is plotted against time (measured in seconds).

6 Relative Power Output (W) Lab 6 PP4, S Smith, per. Mov. Avg. (Series2) 100 per. Mov. Avg. (Series5) 100 per. Mov. Avg. (Series8) Time (s) Figure 2. Relative power output for the participants with the highest and lowest relative power, and the mean relative power for all five participants. This power (measured in Watts) is plotted against time (measured in seconds). Question 3 Within the first few seconds, each participant reached their peak power output. This is due to the maximum rate of the ATP-PC system. There is then a decline in power output as the test progresses. This decline in power during the test is used to test anaerobic endurance and most likely represents the participant s maximal capacity to produce ATP using a combination of both the ATP-PC system and glycolysis (Powers & Howley, 2009). Question 4 The most important personal factors associated with the difference between the participants seem to be sex, preferred sport, and fitness status. The male participant whose preferred sport was cycling and who was well trained reached the highest peak power output and

7 Lab 6 PP4, S Smith, 7 highest relative power output while the female participant whose preferred sport was netball and whose fitness status was only average, had the lowest peak power output and lowest relative power output. EXPERIMENT 2: INVESTIGATION OF MAOD TEST Introduction Purpose and Rationale The purpose of this lab was to measure the energy contribution from anaerobic metabolism. Aim Conduct a Maximal Accumulated Oxygen Deficit (MAOD) test on one participant and deem the physiological and practical implications of supplying energy from anaerobic versus aerobic systems during intense exercise. Hypothesis As the MAOD test progresses, aerobic power output will increase as anaerobic power output will decrease. Methods Participant Only one participant was used for this experiment.

8 Lab 6 PP4, S Smith, 8 Table 3. Participant Details Measurement Value Height 167 cm Weight 75.5 kg Sex Female Resting Heart Rate 80 beats/min Resting Blood Pressure 135/75 Preferred Sport Soccer Fitness Status Average VO2 Max 3.36 L/min VO2 Max Power 275 W (+10% = 303W) Equipment An electromagnetically-braked cycle ergometer (Velotron) was used in this experiment. An automated gas analysis system (Metalyser 3B) was used to analyse expired gas from the participant. This allowed for the calculation of VO2, VCO2, RER, VE, and BF (Breathing Frequency). A scale was used to measure the weight of the participant and a stadiometer was used to measure height. A blood pressure cuff, stethoscope, and sphygmomanometer were used to determine the participant s resting blood pressure. Lastly, a heart rate monitor was used to measure the resting heart rate of the participant. Procedures 1. The Manual Ergo options in the Velotron software were set to start at the correct value. 2. Group roles were organized. One person was in charge of the computer tasks, including the start and stop of the test while watching the time displayed on the screen. Another person started and monitored the gas analysis system. Another person monitored the heart rate of the

9 Lab 6 PP4, S Smith, 9 participant as the test progressed. While another monitored the well being of the participant during the test. 3. The participant s resting variables including resting heart rate and blood pressure were taken and recorded. 4. The cycle ergometer was then adjusted specifically for the participant. 5. Once all of the jobs were assigned, resting variables were recorded, and the bike was adjusted, the participant then began to exercise. 6. The participant warmed up at between 1.0 and 1.5 W kg When the participant was warmed up, they were given one minute to get to a steady state with a cadence above 60rpm. The power was then set to 110% of the VO2 Max Power of the participant on the cycle ergometer and the participant cycled as long as possible at any cadence above 60rpm. 8. The participant can cycle at any cadence. Stop the exercise when the 9. Once the participant s cadence dropped below 60rpm the test was done. 10. The participant was allowed to warm down at between 1.0 and 1.5 W kg 1 and the participants welfare was monitored after the test. Data Analysis O 2 Demand was analysed during this experiment. In order to calculate O 2 Demand, the following equation was used: O 2 Demand (L) = 110% x VO 2 Max (L/min) x time (minutes expressed as a decimal) O 2 Demand for the participant in this experiment was ml.

10 Lab 6 PP4, S Smith, 10 Results Along with demand, O 2 Deficit was also calculated. The equation used to calculate O 2 Deficit is as follows: O 2 Deficit (L) = O 2 Demand (L) - VO 2 (L) Since the O 2 demand was 734.8mL and VO 2 was 35.47mL then the O 2 Deficit was ml or about 7 L. Time (s) Table 4. MAOD Results V'O2 (l/m) V'CO2 (l/m) RER V'E (l/m ) BF (1/m) Time (m) VO2 (%) Work (kj) Watts Consumed Aerobic Watts Output Anaerobic Watts Output

11 Power (Watts) Lab 6 PP4, S Smith, 11 Discussion Question 1 Physiologically, the MAOD is measuring anaerobic capacity. Yes, the MAOD in this experiment does seem to be realistic because the oxygen demand of the participant s exercising muscles exceeded the oxygen supplied. Therefore, there was a deficit (Powers & Howley, 2009). Question Aerobic Watts Output Anaerobic Watts Output Time (min) Figure 4. Profile of energy usage and the energy provided by aerobic and anaerobic energy systems plotted against time in seconds.

12 Lab 6 PP4, S Smith, 12 Question 3 No, the anaerobic energy contribution cannot be specifically separated into phosphagen and glycolytic during the types of measurements collected in this experiment. However, anaerobic contribution is separated into these two components; there just isn t a way to measure them exactly using the methods used in this experiment. Question 4 One major assumption involved in measuring the MAOD is that anaerobic energy supply can be measured by subtracting aerobic energy supply from total energy supply (Powers & Howley, 2009). Question 5 One factor within an individual that would affect their MAOD and high-intensity exercise capability would be the individual s VO2 max. This is because an individual s VO2 max determines the amount of oxygen that can be used during maximal exercise (aerobic energy supply) and thus determines the anaerobic energy supply. If VO2 max was any less than the max demonstrated in the experiment, then the participant would need an increase in anaerobic energy supply which would lead to a decrease in the MAOD test duration (Powers & Howley, 2009).

13 Lab 6 PP4, S Smith, 13 After completing this MAOD test, the same participant completed a vertical jump test. This is a simple way to measure someone s anaerobic capability. The participant jumped using three different methods. The first method was jumping while starting with their knees bent at 90 degrees and without swinging their arms. The second method of jumping was using a stretchshortening cycle without swinging their arms. The third method of jumping was using a stretchshortening cycle with swinging the arms. The results were as follows: Table 5. Vertical Jump Test (Maximum values) Measurement Maximum Value Participant Height 167 cm Standing Reach 216 cm 90 degree knees Total Height 243 cm Calculated Jump Height 27 cm Relative Jump Height 0.16 Stretch- shortening, Total Height 247 cm no arms Calculated Jump Height 31 cm Relative Jump Height 0.19 Stretch- shortening, Total Height 253 cm with arms Calculated Jump Height 37 cm Relative Jump Height 0.22 Question 1 The vertical jump using stretch-shortening cycle (no pause at bottom of crouch), with swinging arms was definitely the most effective jump technique. This technique was 38% more effective than the 90 degree knees technique and 16% more effective than the stretch-shortening, no arms technique.

14 Lab 6 PP4, S Smith, 14 Question 2 The physiological basis for the stretch-shortening with arms jumping technique s effectiveness is the fact that when the arms are able to swing it increases the height and velocity of the centre of mass at take-off. The increased velocity of take-off was from a series of events which allowed the arms to build up energy early in the jump and transfer it to the rest of the body during the later stages of the jump. This energy came from the shoulder and elbow joints as well as from extra work done at the hip. This energy was used to increase the kinetic and potential energy of the arms at take-off, store and release energy from the muscles and tendons around the ankle, knee and hip joint, and pull on the body through an upward force acting on the trunk at the shoulder. All three of these factors together explain the effectiveness of the stretch-shortening with arms jumping technique (Lees, Vanrenterghem, & De Clercq, 2004).

15 Lab 6 PP4, S Smith, 15 References Lees, A., Vanrenterghem, J., & De Clercq, D. (2004). Understanding how an arm swing enhances performance in the vertical jump. Journal of Biomechanics, Powers, S. K., & Howley, E. T. (2009). Exercise Physiology: Theory and Application to Fitness and Performance. New York: McGraw-Hill.