From physical activity intervention to lifestyle routines in overweight adults
Active Commuting To Improve health and Wellbeing in Everyday life (ACTIWE)
By combining biomedical and ethnological approaches, this work package addresses the health effects of physical activity in overweight adults and the possibilities for, and barriers against, physical activity becoming a daily routine.
The overall aim is to evaluate health effects of physical activity in transport and leisure time domains of everyday life, and to develop durable physical activity regimens. I.e. the ambition is to go from ‘intervention’ to ‘daily lifestyle routine’ in overweight individuals.
Time spent on physical activity intersects with different domains of everyday life: at home, during transport, at work and during leisure (Ng SW, Popkin BM, 2012). Previous physical activity interventions have almost exclusively targeted leisure time, and most are of limited duration (<3 months) and involve low exercise levels.
We recently found that 12 weeks of increased leisure time physical exercise (600 kcal/day, vigorous intensity, no dietary changes) reduced body weight by 6 kg and fat mass by 8 kg in moderately overweight men, while peripheral insulin sensitivity increased by 58%, demonstrating that leisure time physical activity can be a powerful enhancer of metabolic health (Nordby P et al., 2012). However, it might be difficult to sustain such a demanding exercise routine in a limited leisure time, and we found in another study that expending 300 kcal/day by vigorous intensity exercise during leisure time was equivalent to expending 600 kcal/day with respect to reduction of fat mass and improvement of metabolic health (Rosenkilde et al., 2012, Reichkendler et al., 2013).
Many aspects of individuals' behaviour and everyday life practices may prevent adopting a healthier lifestyle, and little is known about how to make and keep changes (Brug J et al., 2005). In a public health perspective, the large number of overweight individuals, who are at risk of developing obesity-associated morbidities, are particularly important. Innovation is required to motivate and promote healthy lifestyle choices. Increasing physical activity in other domains of everyday life, such as active commuting (Andersen LB, 2000), could increase applicability and long-term compliance.
A 6-month randomized clinical trial investigates the effects of an increased physical activity level in transport (cycling to work) and leisure time domains (moderate and vigorous intensity endurance training). The target group comprises younger (20-45 years), overweight (BMI 25-35 kg/m2), sedentary men and women, of whom 40 will participate in each intervention group and 20 in a control group.
The primary biomedical endpoint is peripheral insulin sensitivity, and by combining humanistic, technological and biomedical approaches, the specific aims are to:
- Assess physical activity level, including non-exercise activity, in different domains of everyday life.
- Understand determinants of physical activity in these domains.
- Investigate the effects of increased physical activity level in different domains on health and wellbeing.
- Study the subsequent development of the intervention-induced adaptations.
- Determine whether carriers of genetic risk variants for obesity and type 2 diabetes are particularly responsive to lifestyle intervention.
Subjects go through biomedical testing before, during and after the intervention, and will be invited to a follow-up visit 1 year after the end of the intervention. The testing includes determination of cardiovascular fitness, body composition, appetite regulation, blood pressure, insulin sensitivity, energy balance, cardiovascular risk as well as sampling of blood, adipose tissue, skeletal muscle, urine and stool. Personal assistive technology is used to precisely monitor physical activity level and energy expenditure in the different domains.
Determinants of physical activity in the various domains of life are investigated by a targeted ethnological fieldwork combining interviews and a questionnaire about commuting routines, experiences with exercise and previous attempts at lifestyle changes. By following a sample of the intervention population, the challenges of the applied lifestyle changes is identified. The methodology is qualitative, and includes participant observations, in-depth interviews, visual methods and auto-ethnography.
Visions for societal impact
- To produce valid and robust knowledge on the effectiveness of physical activity interventions in other domains of everyday life than leisure time.
- To convert basic scientific knowledge to applicable everyday practices, initiatives and products promoting physical activity, and hereby to pave the way for durable health recommendations for prevention of obesity-associated morbidities.
- Andersen LB, Schnohr P, Schroll M, Hein HO. All-cause mortality associated with physical activity during leisure time, work, sports, and cycling to work. Arch Intern Med 160: 1621-8, 2000.
- Brug J, Oenema A, Ferreira I. Theory, evidence and Intervention Mapping to improve behavior nutrition and physical activity interventions. Int J Behav Nutr Phys Act 2: 2, 2005.
- Ng SW, Popkin BM. Time use and physical activity: a shift away from movement across the globe. Obes Rev 13: 659-80, 2012.
- Nordby P, Auerbach PL, Rosenkilde M, Kristiansen L, Thomasen JR, Rygaard L, Groth R, Brandt N, Helge JW, Richter EA, Ploug T, Stallknecht B. Endurance training per se increases metabolic health in young, moderately overweight men. Obesity (Silver Spring) 2012 March 22.
- Reichkendler MH, Auerbach P, Rosenkilde M, Christensen AN, Holm S, Petersen MB, Lagerberg A, Larsson HB, Rostrup E, Mosbech TH, Sjödin A, Kjaer A, Ploug T, Hoejgaard L, Stallknecht BM. Exercise training favors increased insulin-stimulated glucose uptake in skeletal muscle in contrast to adipose tissue: A randomized study using FDG PET imaging.Am J Physiol Endocrinol Metab. 2013
- Rosenkilde M, Auerbach P, Reichkendler MH, Ploug T, Stallknecht BM, Sjödin A. Body fat loss and compensatory mechanisms in response to different doses of aerobic exercise – a randomized controlled trial in overweight sedentary males. Am J Physiol Regul Integr Comp Physiol 303: R571-9, 2012.