The MILE study: a motivational, individual and locally anchored exercise intervention among 30–49 year-olds with low levels of cardiorespiratory fitness: a randomised controlled study in primary care

BACKGROUND: Low levels of cardiorespiratory fitness are associated with high risk of non-communicable diseases and all-cause mortality. Physical activity level is the primary determinant of cardiorespiratory fitness in adults. However, knowledge on how to motivate people to engage in physical activity and maintain an active lifestyle is lacking. This study aims to investigate whether a motivational, individual, and locally anchored exercise intervention, in primary care, can improve cardiorespiratory fitness in 30 to 49 year olds with a low or very low cardiorespiratory fitness. METHODS/DESIGN: Two-armed randomised controlled trial with 6 and 12 months follow-up. The primary outcome is cardiorespiratory fitness estimated via a maximal incremental exercise test. Secondary outcomes include physical activity level and sedentary behavior (objectively measured), self-reported physical activity, biochemical parameters (HbA(1C), HDL- and LDL-cholesterol, and triglyceride), anthropometric parameters and health-related quality of life. A total of 236 participants with low levels of cardiorespiratory fitness classified at a local health check programme will be randomised. The intervention consists of four motivational interviews, a six months membership to a sport club, and a global positioning watch to upload training activity to Endomondo.com. The comparison group will receive standard care: a one hour motivational interview followed by another interview if requested. Effects will be estimated by evaluating the differences in mean changes in cardiorespiratory fitness between the two groups. DISCUSSION: In new and innovative ways the focus of this study will be to improve cardiorespiratory fitness among a 30–49 year-old at-risk group using social media, Global Positioning System-technology, on-going personal support and individually tailored physical activity. TRIAL REGISTRATION: ClinicalTrials.gov (no.NCT01801956).