The effect of indoor rowing exercise on Mid-Thigh Intermuscular Adipose Tissue Volume, 25-Hydroxyvitamin D, Leptin and Adiponectin levels in young adult obese subjects / Nur Farhana Md Yunus

Increased adiposity in obese individuals could restrict movement and lead to a further sedentary lifestyle. Thus, an optimal exercise programme needs to be identified as an intervention to reduce adiposity. Intermuscular adipose tissue (IMAT) is located in spaces between skeletal muscle bundles and beneath the fascia of the muscle. Like visceral adipose tissue, IMAT seems to be an important fat depot that could lead to health complications. Studies have shown that IMAT volume decreases following either aerobic or combined aerobic and resistance exercise training in obese subjects. Rowing provides both aerobic and resistance exercise training simultaneously. As a non-weight bearing form of exercise, rowing can be regarded as one of the safest exercises for obese adults. However, the effect of indoor rowing exercise on IMAT volume is not known. This study determined the effect of a 12-week indoor rowing exercise programme on mid-thigh IMAT volume; and determines the correlation between the pre and post changes in IMAT volume with that of 25-hydroxyvitamin D (25(OH)D) and adipokines in young adult obese subjects. Twelve young adult obese males and females (aged 1835 years, BMI ≥ 30kg/m²) self-divided into an Intervention and a Control Group (n=6 respectively). The Intervention Group performed rowing exercise at 70-85% HRmax, 3 times per week for 12 weeks. Subjects in the control group continued with their daily activities as per their normal routine. All parameters were measured before and after 12 weeks in each group as well as between the groups. Bilateral mid-thigh (quadriceps) IMAT volume in both groups was determine using MRI scans at week 0 and 12. IMAT volume was then quantified using MATLAB software. 25(OH)D levels was quantified using HPLC, while adipokine levels were quantified using ELISA. There was no significant difference in mid-thigh IMAT volume, 25(OH)D and adipokines following indoor rowing exercise. Moreover, there was no significant correlation between pre and post exercise changes in mid-thigh IMAT volume with that of 25(OH)D, leptin and adiponectin. In conclusion, indoor rowing exercise at 70-85% HR max did not seem to significantly affect mid-thigh IMAT volume, 25(OH)D, and adipokines in young adult obese subjects. This could be due to the small sample size, gender mix, exercise regimen or lack of dietary restriction among these subjects.