Abstract Background Lifestyle greatly contributes to the development of age-related diseases. The goal of the Semmelweis University’s ‘Semmelweis Workplace Health Promotion Program’ is to develop interventions that facilitate healthy ageing. The aim of its first intervention was to increase the step count of participants by incorporating motivational elements offered through the university’s Center of Preventive Services. Methods A randomized controlled trial was conducted in spring 2024 with three study groups: those undergoing motivational interviews (MI, n = 49), those receiving motivational emails (ME, n = 51), and a control group (n = 53). Intervention groups (MI+ME) received weekly emails for 8 weeks emphasizing the benefits of increased step count and providing feedback on achievements. The MI group also took part in 4 biweekly consultations. Mean step counts of last week and energy expended while walking (MET) calculated from the International Physical Activity Questionnaire were recorded five and three times, respectively. Mixed model regressions were conducted for two pre-planned comparisons: MI+ME vs. controls, and MI vs. ME. Results Intervention groups exhibited a significant increase in average step count (1001 steps; 95% Confidence Interval [95% CI]: 349-1651) as a result of the program, while the control group experienced a non-significant decrease. This was accompanied by a significant increase in energy expenditure for walking (45 MET; 95% CI: 4-87) in intervention groups and a non-significant decrease for the control group. The study found no significant differences in step count and energy expenditure between the two intervention groups (MI vs. ME). Conclusions Our results suggest that workplace health promotion programs may effectively increase physical activity, and thus may be key in tackling the challenges posed by aging demographics. Preliminary findings did not indicate a superiority between email-based and motivational interview-based motivation. Key messages • Workplace health promotion is an essential tool in promoting healthy aging among the working-age population. • Step-count programs based on motivational interviewing serve as an effective and simple tool in increasing physical activity.