Health Screening and Analysis and Interpretation of GXT Data
Health Screening and Analysis and Interpretation of GXT Data
John is a 35-year-old archeologist whose job requires some walking and hiking when he is collecting data in the field. However, much of his time is spent analyzing artifacts in the laboratory and writing research reports in his office. He is thinking about joining the employee fitness program at work, and therefore contacted you to evaluate his health risk and aerobic fitness level. His last medical examination was 3 months ago. You gave him a GXT using a Bodyguard cycle ergometer and collected the following data:
| Client: 35-year-old male | Resting BP: 131/92 mmHg |
| Resting HR: 71 bpm | Total cholesterol: 210 mg · dl-1 |
| Height: 5 ft 10 in. (177.8 cm) | HDL-cholesterol: 30 mg · dl-1 |
| Body weight: 175 lb (79.5 kg) | Smoking history: 1 pack per day |
| Activity interests: cycling | Physical activity: job-related walking/hiking |
GXT Data
| Stage | Min | Work rate (kgm · min-1) | HR | BP | RPE |
| 1 | 1 | 180 | 110 | ||
| 2 | 180 | 115 | |||
| 3 | 180 | 119 | 168/92 | 7 | |
| 2 | 4 | 360 | 130 | ||
| 5 | 360 | 136 | |||
| 6 | 360 | 138 | 180/90 | 13 | |
| 3 | 7 | 540 | 151 | ||
| 8 | 540 | 158 | |||
| 9 | 540 | 163 | 215/88 | 16 |
Questions
1. Based on demographic data, list this client’s complete CHD risk profile (e.g. HR – normal). Did a physician need to be present during the GXT (yes/no), given his CHD risk classification?
2. Identify any abnormalities, if any, in the HR and BP responses during the GXT.
3. Why was this GXT terminated at stage 3?
4. Calculate the energy cost of each workload for ALL three stages using the ACSM leg ergometry formula from Table 4.3: [(W/M) x 1.8] + 3.5 + 3.5. Convert ml · kg-1 · min-1 to METs for each stage by dividing the answer in each stage by 3.5. {SHOW WORK}
5. Plot the client’s HR versus workload (in METs) [You may use graph paper or Excel]. Draw a graph (either by hand or using Excel) using the HRs provided plotted against the METs you calculated in #4. For example , if your MET calculation for Stage 1 was 2 METs, then the first point on your graph would be (2, 119) where “2” is the METs and “119” is the corresponding HR. {SHOW WORK}
6. What is the client’s VO2max (in METs and ml/kg/min) using the graphing method? Use the graph that you drew in #5 and draw a “best fit” line through the points. Next draw a horizontal line across the graph that corresponds to the estimated HRmax (220 – age). Lastly, draw a vertical line down from where your best fit line intersects your HRmax line all the way down to the x-axis to determine VO2 max in METs. Multiply your answer by 3.5 to determine ml/kg/min. Hint: Your graph should resemble figure 4.10 in your textbook if you are doing it correctly. {SHOW WORK}
7. Based on your answer to #6 (client’s VO2max), what is this client’s CR fitness classification based on Table 4.1 in your textbook?
8. Based on the fitness classification in #7, use VO2R = [%intensity x (VO2max – VO2Rest)] + VO2Rest] to calculate the client’s target MET zone (minimum and maximum) using the recommended intensity in Table 5.1. Next, plot the target MET zone on the graph paper. Based on the target MET zone on your graph, plot the corresponding target exercise HR (minimum and maximum). According to your graph, what is the target exercise HR zone? [You can use the graph you originally constructed in #6 and plot the target met zone and the target heart rate zone. Hint: Your graph will now begin to resemble figure 5.3]. {SHOW WORK}
9. Now calculate the %HRR: %HRR = [% exercise intensity x (HRmax – HRrest)] + HRrest to identify the target HR zone (minimum and maximum). How do these calculated target HRs compare to those you obtained using the HR versus MET graphing method in #8? {SHOW WORK}
10. How long will he need to cycle at the minimum exercise intensity (in METs) in order to expend 100 kcal during the aerobic workout (pg 132)? Start by using the formula: kcal·min−1 = METs × 3.5 × body mass (kg) / 200. This will give you the number of kcal being burned per minute; then use this information to calculate how long your client will need to cycle to burn 100 kcal. {SHOW WORK}
11. What lifestyle changes do you recommend for this client?
