FatigueMuscle FatigueFatigue Syndrome, ChronicMental FatigueQuestionnairesQuality of LifeSleep DisordersMuscle ContractionMuscle, SkeletalSeverity of Illness IndexIsometric ContractionTime FactorsDepressionPhysical EnduranceTreatment OutcomeFibromyalgiaElectromyographyPainNeoplasmsActivities of Daily LivingAsthenopiaTorqueExerciseCross-Sectional StudiesDiaphragmAnalysis of VariancePsychometricsMuscle StrengthStress, PsychologicalAnxietyChronic DiseaseSleep Initiation and Maintenance DisordersPhysical ExertionReproducibility of ResultsSurvivorsPostpoliomyelitis SyndromeWork Schedule ToleranceSleepElectric StimulationProspective StudiesFollow-Up StudiesPrevalencePain MeasurementDyslexiaLongitudinal StudiesNeurastheniaAdaptation, PsychologicalHealth StatusNeuropsychological TestsSickness Impact ProfileDisability EvaluationMultiple SclerosisDisorders of Excessive SomnolenceBiomechanical PhenomenaTask Performance and AnalysisRisk FactorsMaterials TestingExercise TherapyQuadriceps MusclePsychomotor PerformancePilot ProjectsKneeAffectLearning DisordersFractures, StressCase-Control StudiesStress, MechanicalCognitionMotor ActivityCognition DisordersExercise TestCognitive TherapyPsychiatric Status Rating ScalesActigraphyExercise Tolerance