This study aimed to explore whether a six-week intervention, based on participation in outdoor exercise, including activity-tracking devices and combined with individual consulting sessions, can both increase physical activity and yield positive changes in physiological and psychological health measures. A total of six participants, with a mean age of 41.2 (range 33-50 years), completed the ten-week study and the six-week intervention. The full study consisted of a four-week control/baseline and a six-week intervention period in which each participant acted as their own controls. Continuous measures of physical activity data were collected using a wrist-worn activity sensor during the ten-week study, along with pre- and post-measures of cardiovascular fitness, upper-body strength, BMI, general health, and motivation to exercise. The intervention consisted of a resistance-training programme for an outdoor gym and three motivational interviewing sessions. Effect sizes (percentage) for changes pre- to post-training were calculated. The results, because of the small sample size, are presented as individual cases, but the group, as a whole, showed average increases from baseline (pre-) to post-measures in strength (maximum row; 15.33%), time to exhaustion (3.58%), number of steps per day (4%), and autonomous motivation (12%) and average decreases in body weight (-1.08%), fat percentage (-7.58%), strength (chest; -2.5%), and stress symptoms (-2.17%). The six-week intervention programme showed promising results regarding physical activity changes. This study contributes to the limited evidence of the impact of resistance training programmes using outdoor gyms, electronic tracker, and motivational interviewing on physical activity outcomes. © 2019 by the authors.