FM	Fibromyalgia
ACR	American College of Rheumatology
PBTs	Performance-based tests
PROMs	Patient-reported outcome measures
6MWT	6 min walk test
COSMIN	Consensus-based Standards for the selection of health Measurement Instruments
BMI	Body mass index
WPI	Widespread Pain Index
SSS	Symptom Severity Scale
FIQR	Revised Fibromyalgia Impact Questionnaire
SF-36	36-item Short-Form Health Survey
HADS	Hospital Anxiety and Depression Scale
ICF	International Classification of Functioning, Disability and Health
ICC	Intraclass correlation coefficient
SEM	Standard error of measurement
SRD	Smallest real difference
LoA	Limits of Agreement
EWGSOP2	The European Working Group on Sarcopenia in Older People 2