Effect of E-Bike Versus Bike Commuting on Cardiorespiratory Fitness in Overweight Adults: A 4-Week Randomized Pilot Study.

Objective: To assess if active commuting with an electrically assisted bicycle (e-bike) during a 4-week period can induce increases in cardiorespiratory fitness measured as peak oxygen uptake (...O2peak) in untrained, overweight individuals, and if these changes are comparable with those induced by a conventional bicycle. Design: Four-week randomized pilot study. Setting: Controlled laboratory. Participants: Thirty-two volunteers (28 men) participated. Seventeen {median age 37 years [interquartile range (IQR) 34, 45], median body mass index [BMI] 29 kg/m² [IQR 27, 31]} were randomized to the E-Bike group and 15 [median age 43 years (IQR 38, 45), median BMI 28 kg/m² (IQR 26, 29)] to the Bike group. Interventions: Participants in both groups were instructed to use the bicycle allocated to them (e-bike or conventional bicycle) for an active commute to work in the Basel (Switzerland) area at a self-chosen speed on at least 3 days per week during the 4-week intervention period. Main Outcome Measures: ...O2peak was assessed before and after the intervention in an all-out exercise test on a bicycle ergometer. Results: ...O2peak increased by an average of 3.6 mL/(kg⋅min) [SD 3.6 mL/(kg⋅min)] in the E-Bike group and by 2.2 mL/(kg⋅min) [SD 3.5 mL/(kg⋅min)] in the Bike group, with an adjusted difference between the 2 groups of 1.4 mL/(kg⋅min) [95% confidence interval, -1.4-4.1; P = 0.327]. Conclusions: E-bikes may have the potential to improve cardiorespiratory fitness similar to conventional bicycles despite the available power assist, as they enable higher biking speeds and greater elevation gain. [ABSTRACT FROM AUTHOR]