Physical activity can worsen migraine, leading to reduced activity levels in adults with chronic migraine. This study investigated the change in average steps per day, as a surrogate marker of physical activity, in adults with chronic migraine successfully treated with monoclonal antibodies against calcitonin gene-related peptide or its receptor. Data were obtained from adults with chronic migraine, who were classified as responders to preventive treatment with monoclonal antibodies. The primary endpoint was the difference in a mean number of steps per day between the 3 months prior to treatment initiation and the first 3 months after treatment initiation. The secondary endpoint was the correlation between the change in steps per day and the change in monthly migraine days. Twenty-two (20 females) participants with a median age of 48.5 years were enrolled. The median number of steps per day increased from 4421 at baseline to 5241 after treatment (P = 0.039). We found a positive correlation between the increase in steps per day and the treatment response (P = 0.013). In conclusion, an increase in physical activity, based on steps per day, positively correlated with treatment response to monoclonal antibodies. Automatically registered daily step count data might be used to monitor physical activity as a response to preventive treatment in adults with chronic migraine.