Physiological correlates of pulmonary function in children with cystic fibrosis

and expertise that is not readily available in all centers. Other fitness parameters such as peak anaerobic power, measures of power and strength may be simpler to deliver in the clinic. The relationship between these measures and established outcomes such as forced expiratory volume in one second (FEV1) and peak aerobic power (VO2peak) in CFremains unclear. Therefore we evaluated (a) aerobic fitness, (b) anaerobic fitness, and (c) upper and lower body muscle strength to determine their relationship to FEV1 and VO2peak in children with CF. Methods: Eightytwopatients(7‐18years)withCF(40female)fromtheCFclinicatTheHospitalforSickChildrenin Toronto performed a maximal incremental cycling test to exhaustion. Anaerobic power (W) for 10 and 30sec cycling trials as well as vertical jump (VJ) and hand grip strength (HG) were compared to FEV1 and VO2peak. Results: Absolute VO2peak (R 2 ¼0.16, P<0.001), anaerobic power (R 2 ¼0.21,P<0.001), and hand grip strength (R 2 ¼0.10,P ¼0.003) were significantlycorrelated to lung function whereas measures of explosive lower body strength (VJ) were not. Anaerobic power(R 2 ¼0.16,P ¼0.001)andhandgripstrength(R 2 ¼0.08,P ¼0.01)wererelatedtoVO2peak. Vertical jump was correlated with VO2peak (R 2 ¼0.29, P<0.001) but not FEV1. Conclusions: Simplefitness tests such as hand grip strengthand anaerobiccycle testsmaybe useful indicators