Co-ingestion of carbohydrate and whey protein isolates enhance PGC-1α mRNA expression: a randomised, single blind, cross over study

Abstract

BackgroundWhey protein isolates (WPI) supplementation is known to improve resistance training adaptations. However, limited information is available on the effects of WPI plus carbohydrate (CHO) supplementation on endurance training adaptations.MethodSix endurance trained male cyclists and triathletes (age 29 ± 4 years, weight 74 ± 2 kg, VO2 max 63 ± 3 ml oxygen. kg-1. Min-1, height 183 ± 5 cm; mean ± SEM) were randomly assigned to one of two dietary interventions in a single blind cross over design; CHO or CHO + WPI. Each dietary intervention was followed for 16 days which included the last 2 days having increased CHO content, representing a CHO loading phase. The dietary interventions were iso-caloric and carbohydrate content matched. On completion of the dietary intervention, participants performed an exercise bout, consisting of cycling for 60 min at 70% VO2 max, followed by time trial to exhaustion at 90% VO2 max and recovered in the laboratory for 6 hours. Blood samples and muscle biopsies were taken at various time points at rest and through the exercise trial and recovery.ResultsCompared to CHO, CHO + WPI increased plasma insulin during recovery at 180 mins (P < 0.05) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) mRNA expression at the end of 6 hours of recovery (P < 0.05). Muscle glycogen did not differ between the two trials.ConclusionThis study showed co-ingestion of CHO + WPI may have beneficial effects on recovery and adaptations to endurance exercise via, increased insulin response and up regulation of PGC-1α mRNA expression.

Effects of a Nutritive Administration of Carbohydrates and Protein by Foodstuffs on Skeletal Muscle Inflammation and Damage After Acute Endurance Exercise

“…It will be necessary in future studies to determine insulin levels at multiple time points in the first 60 min after food ingestion. However this interpretation is in line with published data showing that protein/carbohydrate beverages increase insulin levels stronger then carbohydrate beverages [13,17].…”

“…Effects of ingestion of protein/carbohydrate combination's after endurance exercise on of skeletal muscle damage and recovery have been described in the literature and mechanistically linked to a stimulation of insulin secretion [17]. Therefore in this study we have monitored blood glucose levels and also insulin levels at different time points after exercise and protein carbohydrate ingestion.…”

Effects of skeletal muscle energy availability on protein turnover responses to exercise

“…Moreover, this response was also associated with increased peroxisome proliferator-activated receptor-γ (PPAR-γ) activation and expression of PPARγ-coactivator-1α (PGC-1α), putative transcriptional regulators of mitochondrial proteins (Rowlands et al, 2011). Importantly, these findings support recent work demonstrating that 2 weeks of protein-carbohydrate supplementation with endurance training increased PGC-1α mRNA compared with a carbohydrate-only intervention (Hill et al, 2013). We have also shown that protein ingestion increases PGC-1α mRNA following a bout of concurrent resistance and endurance exercise, although this response occurred despite there being no change in mitochondrial protein synthesis rates .…”

Functional effects of milk bioactive peptides on skeletal muscle of rats

“…Endurance exercise influences and stimulates PGC-1α expression (Hill, Stathis, Grinfeld, Hayes, & McAinch, 2013;Lira, Benton, Yan, & Bonen, 2010); even a single exercise bout exerts these effects (Hill et al, 2013). This concept is in accordance with our findings, where the PGC-1α expression increased in all exercised groups, except for Val-Leu group, compared with the control (rest) group.…”