RecruitingBehavioural interventionEffects of Walking in Greenspace and the Built Environment in Adults With Prediabetes: A Randomized Crossover TrialThe goal of this randomized crossover trial is to compare the differences in psychological and physiological effects of walking in two different outdoor environments (urban/suburban commercial environments vs. urban/suburban nature areas/preserves) in adults with prediabetes. The main questions it aims to answer are: * Do psychological measures of stress, anxiety, and affect improve more in one type of outdoor environment over the other? * Do physiological measures of stress improve more in one type of outdoor environment over the other? As this is a crossover trial, participants will serve as their own controls. Researchers will compare both the psychological and physiological effects walking in the two types of outdoor environments. Participants will: * Walk 150-minutes per week for six weeks in each of the two outdoor conditions. * Visit the clinic four times, including before and after each six-week walking period. * Collect saliva samples immediately proceeding or following the four clinic visits. * Return to their pre-study level of physical activity for a 5-week washout period between each of the two walking interventions.