FatigueMuscle FatigueFatigue Syndrome, ChronicMental FatigueDepressionQuestionnairesSeverity of Illness IndexQuality of LifeSymptom AssessmentTreatment OutcomeTime FactorsPainSleep DisordersPsychiatric Status Rating ScalesAnxietyMuscle ContractionMuscle, SkeletalFibromyalgiaPrevalenceProspective StudiesIsometric ContractionFollow-Up StudiesBehavioral SymptomsCross-Sectional StudiesDepressive DisorderPhysical EnduranceNeoplasmsLongitudinal StudiesStress, PsychologicalRisk FactorsElectromyographyPsychometricsChronic DiseaseAsthenopiaAffective SymptomsPain MeasurementOccupational DiseasesExerciseAnalysis of VarianceActivities of Daily LivingComorbidityDyspneaTorqueHealth StatusSurvivorsAffectCognitive TherapyAdaptation, PsychologicalStress Disorders, Post-TraumaticSickness Impact ProfileCohort StudiesRetrospective StudiesDiaphragmPostpoliomyelitis SyndromeSex FactorsPhysical ExertionHeadacheSleepCase-Control StudiesSleep Initiation and Maintenance DisordersReproducibility of ResultsNeurastheniaMuscle StrengthGastrointestinal DiseasesRegression AnalysisAge FactorsAsthmaSelf ReportCoughMultiple SclerosisPilot ProjectsWork Schedule ToleranceNauseaElectric StimulationExercise TherapyDisorders of Excessive SomnolenceNeuropsychological TestsCognition DisordersRespiration DisordersExercise TestSchizophreniaHealth SurveysLogistic ModelsDrug Administration ScheduleLower Urinary Tract SymptomsQuadriceps MuscleDisability EvaluationPsychophysiologic DisordersNetherlandsExercise ToleranceGastroesophageal RefluxFractures, StressMotor ActivityDizzinessSchizophrenic PsychologyMood DisordersMagnetic Resonance ImagingRespiratory Tract DiseasesKneePsychotic Disorders