International Journal of Exercise Science 13(5): 1167-1178, 2020. The purpose of this study was to measure intrinsic motivation following the implementation of motivational coaching strategies in a semester long personalized adult fitness program. Sixty individuals (40 female/ 20 male, age= 48 ± 15 yrs) participated as clients in an undergraduate exercise training program led by student trainers at Taylor University. The program took place during two consecutive semesters, therefore subject participation ranged from one to two semesters. In addition to personalized exercise prescription, student trainers implemented motivational strategies using a motivational coaching guide aimed at increasing individuals’ overall intrinsic motivation. Trainers utilized a coaching checklist to record the motivational strategies used with their client each session. Intrinsic motivation was assessed before and after each program semester using an Intrinsic Motivation Inventory (IMI) and Motivational Client Scale (MCS). Clients’ scores on the IMI increased from 3.38 ± 0.37 to 3.58 ± 0.31 (p\u3c0.001; d= 0.587). Particularly, perceived competence increased from 3.01 ± 0.52 to 3.41 ± 0.49 (p\u3c0.001; d= 0.793). Correspondingly, MCS scores also increased from 3.47 ± 0.72 to 3.87 ± 0.60 (p\u3c0.001; d= 0.608). Specifically, clients’ response to challenge increased from 3.48 ± 0.98 to 4.15 ± 0.65 (p\u3c0.001; d=0.809). Our data indicate that it is possible to improve intrinsic motivation by implementing motivational strategies into a supervised adult fitness program. This finding suggests motivational coaching may be an important part of a standard training protocol for fitness trainers to help combat a public health concern: initiation and adherence to exercise
