Meta-Analysis
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Meta-Anal. Feb 26, 2015; 3(1): 43-53
Published online Feb 26, 2015. doi: 10.13105/wjma.v3.i1.43
Effect of supervised exercise on aerobic capacity in cancer survivors: Adherence and workload predict variance in effect
Rhys Beaudry, Calvin Kruger, YuanYuan Liang, Matthew Parliament, Mark Haykowsky, Margaret L McNeely
Rhys Beaudry, Calvin Kruger, Mark Haykowsky, Margaret L McNeely, Department of Physical Therapy, University of Alberta, Edmonton, Alberta T6G 2G4, Canada
YuanYuan Liang, School of Medicine, Epidemiology and Biostatistics, University of Texas, San Antonio, TX 78229, United States
Matthew Parliament, Margaret L McNeely, Department of Oncology, University of Alberta and Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada
Author contributions: All authors contributed to the design of the research protocol and interpretation of the data; Beaudry R and Kruger C contributed equally to this work; Beaudry R, Kruger C and McNeely ML contributed to the acquisition of data as described in the methods, preliminary data analyses and wrote the paper; Liang Y performed the meta-regression analyses; Liang Y, Parliament M and Haykowsky M reviewed the paper critically for important intellectual content and approved the version to be published.
Conflict-of-interest: The authors declare no conflicts of interest financial or otherwise.
Data sharing: Not applicable as a review not basic or clinical research.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Margaret L McNeely, Assistant Professor, Department of Physical Therapy, University of Alberta, 2-50 Corbett Hall, 116 St. and 85 Ave, Edmonton, Alberta T6G 2G4, Canada. ribeaudr@ualberta.ca
Telephone: +1-780-2481531 Fax: +1-780-4924429
Received: July 29, 2014
Peer-review started: July 29, 2014
First decision: September 16, 2014
Revised: December 23, 2014
Accepted: December 29, 2014
Article in press: December 31, 2014
Published online: February 26, 2015
Processing time: 175 Days and 7.3 Hours
Abstract

AIM: To examine the efficacy of supervised aerobic exercise training on aerobic capacity in survivors of cancer.

METHODS: We conducted a systematic search identifying randomized controlled trials of supervised aerobic exercise interventions among adult cancer survivors with aerobic capacity (VO2max/peak) as the primary outcome. We calculated pooled effect sizes and performed multiple regression moderator analysis.

RESULTS: We identified 18 studies including 1149 survivors of cancer. Studies included mixed cancer groups (4 studies), breast cancer (10 studies), hematological cancers (2 studies), lung cancer (1 study) and liver cancer (1 study). Survivors of cancer who participated in supervised aerobic exercise training improved aerobic capacity (VO2peak) more than controls (18 comparisons, 1093 participants; standardized mean effect: 0.74; 95%CI: 0.52, 0.96; P < 0.001). However, there was significant heterogeneity among the included trials (I2: 63%; P < 0.001). Sixty-six percent of the between-study heterogeneity was explained by differences in exercise adherence and total exercise workload among studies (R2: 65.8%; P < 0.04).

CONCLUSION: Supervised aerobic exercise training provides a moderate-to-large beneficial effect on aerobic capacity among survivors of cancer. Aerobic capacity was improved to a greater degree in exercise studies with better participant attendance and higher overall exercise workload.

Keywords: Exercise; Neoplasms; Physical therapy modalities; Physical fitness; Meta-analysis

Core tip: The optimal exercise prescription for survivors of cancer is unknown and the effect of variations in exercise training parameters on cancer-specific outcomes are poorly understood. Therefore, questions remain over how to best tailor exercise prescriptions to optimize the health outcomes of survivors who are at different time points in their cancer care. We performed a meta-analysis of data from randomized controlled trials examining the effect of supervised aerobic exercise training on aerobic capacity in cancer survivors. We found that aerobic capacity was improved to a greater extent in exercise studies that prescribed a higher exercise workload and had better participant adherence.