title: Effects of exercise dose and type during breast cancer chemotherapy: multicenter randomized trial.
abstract: BACKGROUND
  Exercise improves physical functioning and symptom management during breast cancer chemotherapy, but the effects of different doses and types of exercise are unknown.
  
  
  METHODS
  A multicenter trial in Canada randomized 301 breast cancer patients to thrice-weekly supervised exercise during chemotherapy consisting of either a standard dose of 25 to 30 minutes of aerobic exercise (STAN; n = 96), a higher dose of 50 to 60 minutes of aerobic exercise (HIGH; n = 101), or a combined dose of 50 to 60 minutes of aerobic and resistance exercise (COMB; n = 104). The primary endpoint was physical functioning assessed by the Medical Outcomes Survey-Short Form (SF)-36. Secondary endpoints were other physical functioning scales, symptoms, fitness, and chemotherapy completion. All statistical tests were linear mixed model analyses, and the P values were two-sided.
  
  
  RESULTS
  Follow-up assessment of patient-reported outcomes was 99.0%. Adjusted linear mixed-model analyses showed that neither HIGH (+0.8; 95% confidence interval [CI] = -0.8 to 2.4; P = .30) nor COMB (+0.5; 95% CI = -1.1 to 2.1; P = .52] were superior to STAN for the primary outcome. In secondary analyses not adjusted for multiple comparisons, HIGH was superior to STAN for the SF-36 physical component summary (P = .04), SF-36 bodily pain (P = .02), and endocrine symptoms (P = .02). COMB was superior to STAN for endocrine symptoms (P = .009) and superior to STAN (P < .001) and HIGH (P < .001) for muscular strength. HIGH was superior to COMB for the SF-36 bodily pain (P = .04) and aerobic fitness (P = .03). No differences emerged for body composition or chemotherapy completion.
  
  
  CONCLUSIONS
  A higher volume of aerobic or combined exercise is achievable and safe during breast cancer chemotherapy and may manage declines in physical functioning and worsening symptoms better than standard volumes.
authors.affiliation: Affiliations of authors: Faculty of Physical Education and Recreation (KSC, DC, CCF, LT), Department of Oncology (JRM), School of Public Health (YY), University of Alberta, Edmonton, Canada; School of Kinesiology (DCM, DJ, LBD), Department of Oncology (KG), University of British Columbia, Vancouver, Canada; Division of Medical Oncology, Cross Cancer Institute (JRM), Edmonton, Canada; Division of Medical Oncology, British Columbia Cancer Agency (KG), Vancouver, Canada; Department of Population Health Research, Alberta Health Services (CMF), Calgary, Canada; University of Ottawa Heart Institute (RRD), Ottawa, Canada; Ottawa Hospital Cancer Center (CP, EW, RJS), Ottawa, Canada; Ottawa Hospital Research Institute, Ottawa, Canada (EW, RJS).
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
authors.forename: Donald C
authors.initials: DC
authors.lastname: McKenzie
authors.forename: John R
authors.initials: JR
authors.lastname: Mackey
authors.forename: Karen
authors.initials: K
authors.lastname: Gelmon
authors.forename: Christine M
authors.initials: CM
authors.lastname: Friedenreich
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yasui
authors.forename: Robert D
authors.initials: RD
authors.lastname: Reid
authors.forename: Diane
authors.initials: D
authors.lastname: Cook
authors.forename: Diana
authors.initials: D
authors.lastname: Jespersen
authors.forename: Carolyn
authors.initials: C
authors.lastname: Proulx
authors.forename: Lianne B
authors.initials: LB
authors.lastname: Dolan
authors.forename: Cynthia C
authors.initials: CC
authors.lastname: Forbes
authors.forename: Evyanne
authors.initials: E
authors.lastname: Wooding
authors.forename: Linda
authors.initials: L
authors.lastname: Trinh
authors.forename: Roanne J
authors.initials: RJ
authors.lastname: Segal
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D002170:Canada; D017024:Chemotherapy, Adjuvant; D015444:Exercise; D005260:Female; D006801:Humans; D008875:Middle Aged; D053580:Muscle Strength; D010809:Physical Fitness; D011788:Quality of Life; D016896:Treatment Outcome