Effects of dietary fish oil (FO) supplementation on the skeletal muscle blood flow (BF) response to submaximal treadmill exercise

Dietary supplementation (SUPP) with FO containing docosahexaenoic (DHA) and eicosapentaenoic acid (EPA) has been demonstrated to produce advantageous effects on vascular function. Specifically, FO SUPP has resulted in enhanced brachial artery dilation during rhythmic handgrip exercise (EX). The effects of FO on BF during dynamic full body EX, however, remain unknown. PURPOSE: To test our hypothesis that 6 weeks of dietary SUPP with DHA and EPA enhances the regional BF response to submaximal treadmill EX in the rat hindlimb. METHODS: Following 6 weeks of dietary SUPP with safflower oil (SO) (control; n = 9) or FO (n = 8), heart rate (HR), mean arterial pressure (MAP), and BF to the hindlimb were measured at rest and during submaximal treadmill EX (20 m/min, 10%) via radiolabeled microspheres in male Sprague‐Dawley rats. RESULTS: HR and MAP were not different between SO and FO at rest or EX (P<0.05). BF was not different between SO and FO at rest. During EX, FO exhibited greater BF in 8 of the 28 muscle parts measured as well greater BF (158±9) to the total hindlimb musculature than SO (128±10ml/min/100g) (P<0.05). CONCLUSION: These results demonstrate that 6 weeks of dietary SUPP with FO results in enhanced BF to the hindlimb during submaximal EX. Thus, SUPP with FO may have therapeutic effects on oxygen delivery and vascular function in patients with impaired vascular function and EX tolerance.