TABLE 3

Functional measures of exercise capacity

Test or toolDescriptionConstruct(s)Target populationAdministrationRecall periodRange of scoresFeasibility/cultural validity
iSTEPExternally paced test; speed increases every 2 min Expired gas analysisExpired gas analysisYounger, fitter patientsPerformance test10 minVariablePortable, standardised and easy to administer field exercise test
MSWT15-level modification of ISWT
Office based walk/run test
Peak oxygen uptakeChildrenPerformance test; standard protocol20 minNA10 m required, used in younger and fitter patients
Excludes those with i.v. lines or those requiring oxygen support
PowerSTS1-min sit-to-stand power indexQuadriceps powerModerate–severe CFPerformance test; standard protocol1 minN/AQuick and easy to perform
Triple hop distanceStarting at one end of a tape, asked to hop three times consecutively on dominant leg, trying to cover as much distance as possibleLower extremity powerOlder children and adultsPerformance testNRDistance recorded in cmNR
Vertical jump test90-cm2 mat connected to a timer next to a wall; time off mat converted to a vertical jump (cm) using a controlled (90 degree) and uncontrolled knee anglePower and postureOlder children and adultsPerformance testNRVertical distance recorded in cmNR
3MSTSubmaximal stress test (distance covered in m)Externally paced test (metronome paced at 12 beats·min−1) step up and down a 6-inch step for 3 minGood choice in severe CLDPerformance test; standard protocol3 minNARequires the least amount of space; 6-inch step required
6MWTSubmaximal stress test (distance covered in m)Standard protocol; distance walked within 6 min (enough O2 to maintain saturations >90%)Validated in 7–23 years
Good choice in severe CLD
Performance test; standard protocol6 minNAMost frequently studied exercise test in CF; easy but requires 30 m
30 s or 1-min-STSCardiorespiratory response during a 30-s or 1-min STS test (chair height 40 cm without armrest; full knee extension); as many repetitions as possible in 1 minExercise capacityModerate–severe CFPerformance test; standard protocol1 minTotal number of full repetitions in 30 s or 1 minQuick and easy to perform

iSTEP: incremental field step test; MSWT: modified shuttle walk test; PowerSTS: 1-min sit-to-stand power index; 3MST: 3-min sit-to-stand test; 6MWT: 6-min walk test; STS: sit-to-stand test; ISWT: incremental shuttle walk test; N/A: not applicable; CF: cystic fibrosis; CLD: chronic lung disease.