The consequences of physical inactivity have been well documented [1]. Based on accelerometer data, only five to ten percent of Americans meet recommended guidelines for physical activity [2]. Barriers to physical activity include lack of time, concerns about neighborhood safety, lack of social support, and the monetary cost of equipment, workout attire, and gym fees [3,4]. Because of these barriers, the workplace has been identified as an optimal setting in which to increase physical activity. An innovative workplace intervention, the Booster Break program, is a group-based physical activity session designed for the 15-min work break led by a trained co-worker [5][6][7][8][9][10][11]. The theoretical foundations of the Booster Break program are Social Cognitive Theory, social support, intrinsic motivation, and selfrewards. The program reduces the impact of the aforementioned barriers to physical activity by embedding physical activity as part of the employee workday, which removes the barriers of time, cost, and unsafe environments. Attending one Booster Break session each workday would accumulate 75 min of physical activity each week; attending two Booster Break sessions each workday would accumulate 150 min of physical activity, meeting the Centers for Disease Control and Prevention's physical activity recommendations [4].Quantitative and qualitative evidence supports the efficacy of the Booster Break program. Participants in a six month Booster Break program significantly improved their HDL levels and lost an average of 14 pounds [5]. Furthermore, other studies found that the Booster Break program encourages a mind set to adopt healthy behaviors, increases co-worker camaraderie, and promotes a health-enhancing culture at the workplace [6]. In a cluster-randomized controlled trial with three conditions (n=175), Booster Break participants were 6.8 and 4.3 times more likely to have decreases in BMI and weekend sedentary time, respectively, than usual-break participants [8]. To illustrate the impact of the Booster Break program, a Booster Break participant have dropped 70 pounds and feel as though I am becoming a new person with a new viewpoint. I say without hesitation that as the pounds have dropped, my energy has increased and I credit the Booster Break with igniting a fire in me [7].As with any workplace health promotion program or innovation, the challenge is the progression from efficacy to effectiveness. While the Booster Break program has demonstrated successful health improvements among those who attend regularly, as with many voluntary, workplace health promotion programs, maintaining high attendance levels is a challenge. To maintain and sustain high attendance rates during the Booster Break program, behavioral economic strategies provide a promising approach. Behavioral economic strategies (e.g., conditional payments, deposit contracts, regret lotteries, and point systems) have proven effective in promoting health behavior change for individuals outside of the workplace [12]. What is not known is whe...