Evaluation of the SenseWear activity monitor during exercise in cystic fibrosis and in health.

Objective: Determine the SenseWear Pro3 Armband (SWA) accuracy for estimating energy expenditure (EE) and step count during treadmill walking in cystic fibrosis (CF) compared to healthy adults.

Hypothesis: SWA estimation of EE would be less accurate for CF, than for healthy subjects, due to interference with the SWA skin sensors caused by the high salt concentration in the sweat of CF subjects.

Methods: 17 CF (mean age 26 yr; FEV1 54% predicted) and 17 age-matched control subjects walked slightly faster than their comfortable pace on a treadmill for 20 min, whilst simultaneously wearing the SWA and breathing through an open-circuit indirect calorimetry (IC) system.