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Implementing a Linear Ramp Treadmill Exercise Protocol

2018; American Association for Respiratory Care; Volume: 63; Linguagem: Inglês

1943-3654

Garner Faulkner, Brenda G Money, Larry Schellenberg, Cara Castro, Bonnie Crabb-Henry, János Pórszász, William W. Stringer, Timothy A. Morris,

Sports Performance and Training

Background: Cardiopulmonary exercise tests (CPET) provide valuable information regarding cardiac and pulmonary function during exercise. Treadmill protocols progressively increase speed and elevation over time, but the increase in work rate is almost always non-linear. Because of arbitrary increases in speed (1 mph) and incline (4% grade) in our prior protocol, the responses were non-linear and showed an uneven distribution of exercise tolerance. We implemented a linearized treadmill protocol1 that is designed to provide even increments in work rates for all patients. Methods: Based on the protocol developed by Porszasz et al1, we developed 63 distinct exercise protocols, corresponding to weight increments of 5 kg starting from 50kg to 150kg and three estimated exercise tolerances: low (50W), medium (100W), and high (150W). The work rate is increased linearly with time by changing both speed and incline. We used a uniform increase in speed up to a max of 5. 7 mph in all protocols and the incline depended on the body weight of the subject. We choose the protocol to be used based on the estimated peak work rate and the body size of each subject. Protocols were programmed into Cardiosoft (Version 6. 73, GE Healthcare Milwaukee WI) that was connected to the TrackMaster (TMX428CP, Full Vision Inc. Newton KS) treadmill in two laboratories. Results: Ten healthy employee/student volunteers were tested (5 Female/5 Male). Their age range was 26-65 y (Mean: 40 ± 12.6 y). Protocol was chosen based on the person9s weight (rounded up to the nearest 5 kg) and the estimated peak work rate (50, 100 or 150 W). The protocol chosen resulted in test durations of greater than 10 min. Subjectively, persons tested felt the linear ramp protocols transitioned smoother/easier compared to the previous protocol. We observed that our new treadmill protocol gave us to the ability of individualizing work rate increments to produce optimal/near optimal duration (at least 10 min) based on specific patients and exercise tolerance. Conclusions: With our previous fixed protocol, patients with low exercise tolerance (such as heart failure) often yielded a short exercise duration limiting the evaluation. With the newly implemented linear ramp protocols we have more flexibility (compared to our previous protocol) in testing a variety of patient populations. With this new approach we expect to continue optimal test durations, giving the clinician/physician sufficient data for analysis. 1. Porszasz J, Casaburi R, Somfay A., Woodhouse L., Whipp B.J.: A treadmill ramp protocol using simultaneous changes in speed and grade. Med Sci Sports Exerc. 2003; 35(9):1596-603.