title: Mediators of Exercise Effects on HRQoL in Cancer Survivors after Chemotherapy.
abstract: We investigated the hypothesis that combined resistance and endurance exercise improves cardiorespiratory fitness and muscle strength, thereby reducing fatigue and improving global quality of life (QoL) and physical function among cancer survivors who completed curative treatment including chemotherapy.
  
  
  
  Cancer survivors were assigned to a 12-wk exercise intervention (n = 186) or a wait list control group (n = 91). Data were collected at baseline and after 12 wk. Path analyses using follow-up values adjusted for baseline values, age, and gender were conducted to test if the exercise effects on global QoL and physical function (European Organization Research and Treatment of Cancer Quality of Life questionnaire-Core 30) were mediated by changes in cardiorespiratory fitness (peak V˙O2), hand-grip strength, lower body muscle function (30-s chair stand test), and fatigue (Multidimensional Fatigue Inventory).
  
  
  
  Compared with the wait list control, exercise increased cardiorespiratory fitness (β = 1.8; 95% confidence interval (CI), 1.0-2.6 mL·kg·min) and reduced general (β = -1.0; 95% CI, -1.8 to -0.2) and physical fatigue (β = -1.5; 95% CI, -2.3 to -0.6). The exercise effect on physical fatigue was mediated by change in cardiorespiratory fitness (β = -0.2; 95% CI, -0.4 to -0.1). Higher hand-grip strength was significantly associated with lower physical fatigue and better lower body muscle function with lower physical and general fatigue. Lower general fatigue and physical fatigue were significantly associated with higher global QoL (β = -1.6; 95% CI, -2.2 to -1.1; and β = -1.7; 95% CI, -2.3 to -1.1, respectively) and physical function (β = -1.0; 95% CI, -1.3 to -0.7; and β = -1.2; 95% CI, -1.6 to -0.9, respectively). The models explained 44%-61% of the variance in global QoL and physical function.
  
  
  
  Beneficial effects of exercise on global QoL and physical function in cancer survivors were mediated by increased cardiorespiratory fitness and subsequent reductions in fatigue.
authors.affiliation: 1Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, THE NETHERLANDS; 2Department of Public and Occupational Health and the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, THE NETHERLANDS; 3Department of Sports Medicine, Máxima Medical Center, Veldhoven, THE NETHERLANDS; 4Department of Clinical Psychology, VU University, Amsterdam, THE NETHERLANDS; and 5Department of Otolaryngology-Head and Neck Surgery, VU University Medical Center, Amsterdam, THE NETHERLANDS.
authors.forename: Joeri
authors.initials: J
authors.lastname: Kalter
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Kampshoff
authors.forename: Mai J M
authors.initials: MJ
authors.lastname: Chinapaw
authors.forename: Willem
authors.initials: W
authors.lastname: VAN Mechelen
authors.forename: Francisca
authors.initials: F
authors.lastname: Galindo-Garre
authors.forename: Goof
authors.initials: G
authors.lastname: Schep
authors.forename: Irma M
authors.initials: IM
authors.lastname: Verdonck-DE Leeuw
authors.forename: Johannes
authors.initials: J
authors.lastname: Brug
authors.forename: Laurien M
authors.initials: LM
authors.lastname: Buffart
mesh_terms: D000072599:Cardiorespiratory Fitness; D005081:Exercise Therapy / Q000379:methods*; D005221:Fatigue / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D009369:Neoplasms / Q000628:therapy*; D011788:Quality of Life; D055070:Resistance Training; D017741:Survivors