First Advisor

Reid Hayward

Date Created

5-2017

Abstract

Exercise improves cardiovascular function in cancer survivors (CS) suffering from treatment-related toxicities, such as decreased peak oxygen consumption (VO2peak). Establishing valid assessment protocols that determine VO2peak are essential for developing individualized exercise prescriptions for cancer rehabilitation programs. The University of Northern Colorado Cancer Rehabilitation Institute (UNCCRI) has developed a valid cancer-specific VO2peak treadmill protocol to address this need. The six-minute walk test (6MWT) is an exercise assessment used in many populations with chronic disease to predict VO2peak but it is not clear whether this test accurately assesses VO2peak in CS. The 6MWT is simple, inexpensive, and representative of daily living activities. Purpose: To assess the validity of predicted VO2peak from the 6MWT compared to the UNCCRI treadmill protocol in CS. Methods: 128 CS completed a UNCCRI treadmill protocol and a 6MWT one week apart in randomized order to obtain VO2peak (mL/kg/min). VO2peak values from the UNCCRI treadmill protocol were compared against four common 6MWT VO2peak prediction equations. Results: All four 6MWT prediction equations significantly (p < 0.001) underestimated VO2peak with predicted values ranging from 8.3 ± 3.8 to18.9 ± 3.0 mL/kg/min, while the UNCCRI treadmill protocol yielded a much higher value of 24.7 ± 7.4. A positive strong correlation occurred between the UNCCRI treadmill protocol and one of the 6MWT prediction equations (r = 0.83) and a moderately strong correlation occurred between the UNCCRI treadmill protocol and another 6MWT equation (r = 0.70). Maximum heart rates were significantly higher (p < 0.001) during the UNCCRI treadmill protocol compared to the 6MWT (150 ± 21 bpm vs. 109 ± 21 bpm). Conclusion: These findings suggest that the 6MWT is not a valid test for predicting VO2peak in CS due to its underestimation when using all four equations. The UNCCRI treadmill protocol is a more accurate means of assessing VO2peak in CS in order to correctly prescribe an individualized exercise rehabilitation program.

Keywords

Cancer rehabilitation, Exercise

Extent

76 pages

Local Identifiers

SchumacherThesis_201705

Rights Statement

Copyright is held by the author.

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