title: Muscle endurance, cancer-related fatigue, and radiotherapy in prostate cancer survivors.
abstract: BACKGROUND
  In this study we investigated muscle and cancer-related fatigue (CRF) in prostate cancer survivors (CS) undergoing radiotherapy (RT).
  
  
  METHODS
  In 13 CS and 12 controls, CRF was assessed by the Piper Fatigue Scale (PFS), Epworth Sleepiness Scale--Depression subscale (CES-D), physical activity (accelerometer), and hemoglobin levels (Hb). Muscle measures included strength, activation, contractile properties, and endurance during intermittent dorsiflexion. Testing occurred before and after 6 weeks of RT in CS.
  
  
  RESULTS
  After RT, the PFS score increased from initial levels in CS only without changes in sleepiness, depression, or physical activity. Hb decreased in CS only [mean (SD): pre, 15 (1.1); post, 14.5 (1.1) g/dl; P = 0.04]. Endurance decreased in CS [mean (SD): pre, 519 (340) s; post, 388 (203) s; P = 0.04] and increased in controls [mean (SD: pre, 616 (387) s; post, 753 (553) s; P = 0.03]. Only endurance was associated with PFS in CS (r = -0.55, P = 0.05).
  
  
  CONCLUSIONS
  Muscle endurance is impaired after RT and may contribute to CRF in CS.
authors.affiliation: Exercise Science Program, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, USA.
authors.forename: Carlynn A
authors.initials: CA
authors.lastname: Alt
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Gore
authors.forename: Marcos L
authors.initials: ML
authors.lastname: Montagnini
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Ng
mesh_terms: D000368:Aged; D005221:Fatigue; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D011471:Prostatic Neoplasms / Q000503:physiopathology* / Q000523:psychology / Q000532:radiotherapy*; D017741:Survivors / Q000523:psychology