Undergraduate Honors Theses

Thesis Defended

Spring 2016

Document Type


Type of Thesis

Departmental Honors


Integrative Physiology

First Advisor

William C. Byrnes

Second Advisor

David E. Sherwood

Third Advisor

Darna Dufour


Pedelecs are a specific form of electric assist bicycles that have a modest electric motor, which provides assist only when the rider is pedaling. Such bikes may help to overcome the hurdles associated with active commuting for those individuals who are leading a sedentary lifestyle. This project was part of a larger study looking at physiological changes resulting from a pedelec intervention. The purpose of this project was to use a 4-week intervention period to study changes in body composition in a sedentary population, through the use of these bicycles. Fourteen physically inactive individuals (4 males, 11 females) visited the lab for baseline physiological testing and body composition scans. During the 4 weeks following their preliminary testing, subjects commuted to and from their work using the pedelecs while wearing a heart rate monitor and GPS device. Individualized regression equations were used to estimate energy expenditure and METS for subjects based on their VO2max test data and their riding data from the monitoring devices. RIndiParticipants were asked to ride at least 40 min/day, 3 days/week in order to fulfill the required intervention stimulus for the study. After the intervention, participants returned to the lab for repeated physiological testing and body composition scans. Multiple regression analysis and paired t tests were used to assess how starting physiological values of the individuals, and their riding tendencies effected changes in body composition. The larger study found significant changes in VO2max, power output at VO2max, and glucose regulation. No significant changes in body composition were observed, although an average decrease of a .53 kg and .44 kg of total mass and fat mass were lost respectively, indicating improvement patterns were present. A dose response pattern was also indicated by fat mass loss, although not significant. Usage of a pedelec over a four-week period is a good intervention for promoting physical activity, as well as improving some physiological parameters, despite the absence of significant body compositional changes. A longer duration and more frequent riding patterns may lead to significant changes in body composition, as well as increase the significance of other physiological findings, and should be a focus for further research regarding electric assist bicycle interventions.