Moderate-intensity aerobic and resistance exercise is safe and favourably influences body composition in patients with quiescent Inflammatory Bowel Disease. A randomized cross-over trial

Background and Aims: Overweight and metabolic problems now add to the burden of illness in patients with Inflammatory Bowel Disease. Therefore, we aimed to determine if a program of aerobic and resistance exercise could safely achieve body composition changes in patients with Inflammatory Bowel Disease. Methods: A randomized, cross-over trial of 8-weeks combined aerobic and resistance training on body composition assessed by Dual Energy X-ray Absorptiometry was performed. Patients in clinical remission and physically inactive with a mean age (?Standard Deviation) of 25 (?6.5) years and Body Mass Index of 28.9 (?3.8) were recruited from a dedicated Inflammatory Bowel Disease clinic. Serum cytokines were quantified, and microbiota composition determined using metagenomic sequencing. Results: Improved physical fitness was demonstrated in the exercise group by increases in median estimated VO2max (Baseline estimated VO2max: 43.41mls/kg/min; post-intervention: 46.01mls/kg/min; p=0.03). Improvement in body composition was achieved by the intervention group (n=13) with a median decrease of 2.1% body fat compared with the non-exercising group (n=7) (0.1% increase; p=0.022). Lean tissue mass increased by a median of 1.59kg and fat mass decreased by a median of 1.52kg in the exercising group. No patients experienced a deterioration in disease activity scores during the exercise intervention. Minimal alterations in the ?- and ?-diversity of gut microbiota and associated metabolic pathways were evident. Conclusions: Moderate-intensity combined aerobic and resistance training is safe in physically unfit patients with quiescent Inflammatory Bowel Disease and can quickly achieve favourable body compositional changes without adverse effects.