Prolonged sitting is associated with increased mortality along with impaired glucose tolerance, obesity, and cardiovascular disease. However, in the modern world, over half of the day is spent sitting. Research has begun to examine potential countermeasures to reduce sitting in traditionally sedentary situations (i.e. the workplace). Various interventions have been proposed but many have drawbacks that limit their use. Cycling-based interventions have potential to help overcome many of these limitations while also improving cardiometabolic risk factors.

This dissertation focused on how cycling could be an effective physical inactivity countermeasure. First, light-intensity motor-driven passive cycling was examined in the laboratory to establish its potential as a workplace intervention. Next, to better determine the effectiveness of cycling in the workplace, a real-world intervention was performed with sedentary office workers. Lastly, because sitting during the commute to work is associated with negative health consequences, an intervention which replaced a sedentary commute with riding a pedelec electric bicycle was studied.

Across all participants, passive cycling doubled energy expenditure compared to sitting and also did not influence basic measures of cognition. In non-lean participants, plasma glucose following an oral glucose tolerance test (OGTT) was 10% lower after passive cycling compared to sitting. This improvement was similar to that seen after moderate-intensity active cycling despite a 66% lower energy expenditure.

In a real-world workplace involving sitting ≥6 h⋅d⁻¹, the cycling intervention increased VO₂max by 4% and power output at the end of the VO₂max test by 6%. The light-intensity cycling was not enough to further improve other cardiometabolic risk factors in the sedentary yet healthy office workers.

While riding a pedelec electric bicycle, participants self-selected to ride at a moderateintensity despite receiving motor assistance. In only four weeks, the cycling intervention decreased OGTT glucose by 9%, increased O2max by 8%, and increased power output at the end of the VO₂max test by 15%.

Overall, various forms of cycling can effectively be used as countermeasures for physical inactivity and improve some cardiometabolic risk factors. Future research should examine interventions over longer durations, other problematic sitting times (i.e. while watching TV), and include populations with greater risk factors.