Fish oil supplementation suppresses resistance exercise and feeding‐induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men

摘要

Fish oil (FO) supplementation potentiates muscle protein synthesis (MPS) in response to a hyperaminoacidemic–hyperinsulinemic infusion. Whether FO supplementation potentiates MPS in response to protein ingestion or when protein ingestion is combined with resistance exercise (RE) remains unknown. In a randomized, parallel group design, 20 healthy males were randomized to receive 5 g/day of either FO or coconut oil control (CO) for 8 weeks. After supplementation, participants performed a bout of unilateral RE followed by ingestion of 30 g of whey protein. Skeletal muscle biopsies were obtained before and after supplementation for assessment of muscle lipid composition and relevant protein kinase activities. Infusion of l‐[ring‐¹³C6] phenylalanine was used to measure basal myofibrillar MPS at rest (REST), in a nonexercised leg following protein ingestion (FED) and following RE and protein ingestion (FEDEX). MPS was significantly elevated above REST during style="fixed-case">FEDEX in both the style="fixed-case">FO and style="fixed-case">CO groups, but there was no effect of supplementation. There was a significant increase in style="fixed-case">MPS in both groups above style="fixed-case">REST during style="fixed-case">FED but no effect of supplementation. Supplementation significantly decreased pan style="fixed-case">PKB activity at style="fixed-case">REST in the style="fixed-case">FO group but not the style="fixed-case">CO group. There was a significant increase from style="fixed-case">REST at post‐ style="fixed-case">RE for style="fixed-case">PKB and style="fixed-case">AMPK α2 activity in the style="fixed-case">CO group but not in the style="fixed-case">FO group. In style="fixed-case">FEDEX, there was a significant increase in p70S6K1 activity from style="fixed-case">REST at 3 h in the style="fixed-case">CO group only. These data highlight that 8 weeks of style="fixed-case">FO supplementation alters kinase signaling activity in response to style="fixed-case">RE plus protein ingestion without influencing style="fixed-case">MPS.