Motivations to exercise in young men following a residential weight loss programme conducted in National Service - a mixed methods study

BACKGROUND: Physical activity is a critical component of lifestyle interventions to reduce body weight and maintain weight loss. The goal of this study was to examine the motivations to exercise in young men following a 5-month residential weight loss programme conducted in the Singapore military as part of National Service. METHODS: We conducted a sequential mixed methods study starting with three focus groups comprising 21 programme instructors. Fifteen former programme participants aged 20.8 years (±1.4) with an average body mass index (BMI) of 29.3 kg/m(2) (±4.6) were interviewed in-depth over a total duration of 9 h. Another 487 current programme participants aged 20.8 years (±1.1), BMI 27.1 kg/m(2) (±2.6), completed a survey on weight loss, physical fitness, and motivations to exercise using the Behaviours Regulating Exercise Questionnaire (BREQ-3). Qualitative data was coded thematically using the six constructs of exercise motivation described by self-determination theory: amotivation, external, introjected, identified and integrated regulation and intrinsic motivation. Quotes from interviewees were cross-tabulated according to their weight maintenance trajectories. BREQ-3 responses were analysed according to initial body mass index (BMI), percentage weight loss and fitness. RESULTS: Over the course of the residential programme interview and survey participants experienced an average weight loss of 15.6 kg (±6.5) and 13.0 kg (±5.4) respectively. Among the fifteen interviewees seven had gained no more than 34% of initial weight loss 6 months after completing the programme while another eight had gained more than 51%. We elicited three key themes from the data: (1) Barriers to exercise; (2) diminishing extrinsic motivation; and (3) unidentified exercise benefits. The integration of findings uncovered reinforcing motivational patterns in the areas of health, fitness, camaraderie and identified regulation. Narratives of self-acceptance and shift-work environments gave rise to potentially deleterious motivational patterns. Our findings suggest that successful transition from a residential programme to independent weight management requires a more deliberate pivot from predominantly extrinsic to intrinsic motivational approaches. CONCLUSION: Residential programmes such as the one investigated here, should develop a deliberate transition strategy, replace weight loss targets with physical performance goals and promote sports that are appropriate for young men affected by overweight and obesity. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-021-10373-z.