Influence of dietary restriction and low‐intensity exercise on weight loss and insulin sensitivity in obese equids

Background The importance of including exercise with dietary modification for the management of obese equids is not clearly understood. Objectives To evaluate the effect of a practical low‐intensity exercise regimen, in addition to dietary restriction, on indices of insulin sensitivity (SI) and plasma adipokine concentrations in obese equids. Animals Twenty‐four obese (body condition score [BCS] ≥ 7/9) horses and ponies. Methods Over a 12‐week period, animals received either dietary restriction only (DIET) or dietary restriction plus low‐intensity exercise (DIET+EX). All animals were provided with a restricted ration of grass hay at 1.25% body weight (BW) on a dry matter basis, providing 82.5% estimated digestible energy requirements. The DIET+EX group undertook low‐intensity exercise 5 days per week on an automated horse walker. Before and after weight loss, total body fat mass (TBFM) was determined, indices of SI were calculated using minimal model analysis of a frequently sampled IV glucose tolerance test, and adipokines plus inflammatory biomarkers were measured using validated assays. Results Decreases in BCS, BW, and TBFM were similar between groups (all P  > .05). After weight loss, animals in both groups had decreased basal insulin and leptin concentrations, and increased adiponectin concentrations (all P  < .001). Furthermore, animals in the DIET+EX group had significantly improved SI and decreased serum amyloid A concentrations relative to animals in the DIET group (both P  = .01). Conclusions and Clinical Importance Regular low‐intensity exercise provided additional health benefits compared with dietary restriction alone in this population of obese equids.