Co-ingestion of carbohydrate and whey protein increases fasted rates of muscle protein synthesis immediately after resistance exercise in rats

Abstract

The objective of the study was to investigate whether co-ingestion of carbohydrate and protein as compared with protein alone augments muscle protein synthesis (MPS) during early exercise recovery. Two months old rats performed 10 repetitions of ladder climbing with 75% of body weight attached to their tails. Placebo (PLA), whey protein (WP), or whey protein plus carbohydrate (CP) was then given to rats by gavage. An additional group of sedentary rats (SED) was used as controls. Blood samples were collected immediately and at either 1 or 2 h after exercise. The flexor hallucis longus muscle was excised at 1 or 2 h post exercise for analysis of MPS and related signaling proteins. MPS was significantly increased by CP compared with PLA (p<0.05), and approached significance compared with WP at 1 h post exercise (p = 0.08). CP yielded a greater phosphorylation of mTOR compared with SED and PLA at 1 h post exercise and SED and WP at 2 h post exercise. CP also increased phosphorylation of p70S6K compared with SED at 1 and 2 h post exercise. 4E-BP1 phosphorylation was inhibited by PLA at 1 h but elevated by WP and CP at 2 h post exercise relative to SED. The phosphorylation of AMPK was elevated by exercise at 1 h post exercise, and this elevated level was sustained only in the WP group at 2 h. The phosphorylation of Akt, GSK3, and eIF2Bε were unchanged by treatments. Plasma insulin was transiently increased by CP at 1 h post exercise. In conclusion, post-exercise CP supplementation increases MPS post exercise relative to PLA and possibly WP, which may have been mediated by greater activation of the mTOR signaling pathway.

Endurance-Type Exercise Increases Bulk and Individual Mitochondrial Protein Synthesis Rates in Rats

“…However, exercise did not result in significantly higher mixed muscle protein synthesis rates when compared to the sedentary rats (Figure 1). This finding is in contrast with some (Gasier et al, 2010;Kubica et al, 2005;Mosoni et al, 1995;Munoz et al, 1994;Wong & Booth, 1990;Ogasawara et al, 2016;Ogasawara et al, 2014), but not all (Katzeff et al, 1995;Wang et al, 2017) studies that have assessed the impact of exercise on mixed muscle protein synthesis rates in rats. The absence of a response may be explained by a relatively low (or negative) synthetic response of proteins residing outside of the myofibrillar and mitochondrial sub-fractions.…”

Seaweed Supplementation Enhances Maximal Muscular Strength and Attenuates Resistance Exercise-Induced Oxidative Stress in Rats

“…In our study, we employed high-intensity progressive RE protocol (ladder-climbing) and found increased FHL muscle mass and maximal weight carrying capacity of rats after 10 weeks. Ladder-climbing resistance training with progressive overloads has been demonstrated to increase muscular strength or maximal weight carrying capacity of rats even after 8 weeks [28, 31, 32]. The key finding of our study is that seaweed in combination with RE further enhances the weight carrying strength.…”

Low-fat, lactose-free and leucine-enriched chocolate cow milk prototype: A preliminary study on sensorial acceptability and gastrointestinal complaints following exhaustive exercise

“…The need for this CHO:PRO combined intervention is justified by previous evidence regarding an increased muscle glycogen storage, muscle damage amelioration, and greater acute and chronic training adaptations in the above mentioned sport-workload context [ 2 ]. By addressing such mechanisms in detail, it is evident that the CHO:PRO mixture improves the acute recovery process via stimulation of muscle protein synthesis (MPS), as well as the activation of the target mechanism of rapamycin ( mTOR ), signalling a pathway [ 5 , 6 ] and a more effective glycogen storage via insulinotropic response [ 7 , 8 ].…”