Introduction Cardiovascular mortality risk is significantly increased by inactivity. Nevertheless, most patients with diabetes fail to achieve the recommended amount of weekly physical activity. Thus, strategies to establish and maintain an active lifestyle are required. Objective The aim of the present study was to examine the effects of a 6‐month running program, Diabetes Programme Germany (DPD), on adherence, body mass index (BMI), hemoglobin A1c (HbA1c), and health‐related quality of life (HRQOL). Methods/Results A retrospective analysis of 428 participants with type 1 (n = 177) and type 2 diabetes (n = 251) was performed. Adherence at 6 months was 75.5%. For participants who completed the program, there was a reduction in HbA1c of 0.3 ± 1.0% (P ≤ .001) and BMI of 0.7 ± 1.1 kg/m2 (P ≤ .001). The greatest improvements were seen in participants with obesity (−1.3 ± 1.7 kg/m2; P ≤ .001) and with type 2 diabetes and a baseline HbA1c ≥7.5% (−1.4 ± 1.7%, P ≤ .001). In a post‐interventional survey (response rate: n = 83), participants reported an above‐average physical HRQOL. Mental HRQOL showed no significant difference from other patients with diabetes. Conclusion The program's success was confirmed by a high adherence and significant reductions in BMI and HbA1c. Furthermore, a positive effect, especially on physical HRQOL, can be assumed.