A Sled Dog Model for Positive Health Effects of Weight Management and Exercise.

Obesity is a significant risk factor for metabolic syndrome and type II diabetes. Physical activity and/or dietary modification can reduce the incidence of obesity. Marginal fitness levels limit the efficacy of exercise training, and most humans choose from a wide range of dietary strategies to lose weight. Despite these limitations, exercise in the absence of weight loss may offer protective benefits against the development of metabolic syndrome and type II diabetes. To examine the benefits of exercise training with and without weight loss, we measured changes in metabolic indices in conjunction with moderate body weight gain, exercise training with no intended change in body weight, and exercise training with bodyweight reduction in a healthy canine model. We measured glucose transporter type 4 on peripheral blood mononuclear cells, plasma glucose, hemoglobin A1c, tumor necrosis factor-alpha, interleukin 6, and insulin levels before, during, and after weight gain, exercise, and weight loss. Weight gain increased plasma glucose, while exercise increased glucose transporter by 4% in peripheral blood mononuclear cells. We also observed changes to plasma glucose, glucose transporter 4, and tumor necrosis factor-α which may be indicative of reduced insulin sensitivity with exercise and weight loss, potentially due to the high energy demand coupled with low caloric availability.