Effect of a lifestyle intervention on change in cardiorespiratory fitness in adults with type 2 diabetes: results from the Look AHEAD Study

Objective: To examine the effect of an intensive lifestyle weight loss intervention (ILI) compared to diabetes support and education (DSE) on changes in fitness and physical activity in the Look AHEAD trial. Design: Randomized clinical trial to compare a lifestyle intervention for weight loss with a DSE condition in individuals with type 2 diabetes. Subjects: Data from 4376 overweight or obese adults with type 2 diabetes (age=58.7±6.8 years, body mass index (BMI)=35.8±5.8 kg/m 2 ) who completed 1 year of the Look AHEAD trial and had available fitness data were analyzed. Intervention: Subjects were randomly assigned to DSE or ILI. DSE received standard care plus three education sessions over the 1-year period. ILI included individual and group contact throughout the year, restriction in energy intake and 175 min per week of prescribed physical activity. Measurements: Fitness was assessed using a submaximal graded exercise test. Physical activity was assessed by questionnaire in a subset of 2221 subjects. Results: Change in fitness was statistically greater in ILI vs DSE after adjustment for baseline fitness (20.9 vs 5.7%; P