We investigate how two digitally delivered nudges, namely light social support (non-verbal cues such as kudos or likes) and motivational messaging, affect employees’ self-reported physical activity in an online, corporate wellness program. Within this unique field setting with data over several years, we find evidence that both types of nudges provide benefits beyond the effect of cash incentives. However, the effects vary by individuals, depending on whether the employee is active in exercising, and by time, depending on how long the employee has been in the wellness program. While light social support is found to be less effective over time, motivational messages are more effective with the duration in the program and generally more effective for inactive users. Our findings have implications for the design of wellness systems, suggesting different approaches depending on an employee’s current activity level and tenure with the program.