Coingestion of Carbohydrate and Protein on Muscle Glycogen Synthesis after Exercise: A Meta-analysis

Abstract

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The Effect of Consuming Carbohydrate With and Without Protein on the Rate of Muscle Glycogen Re-synthesis During Short-Term Post-exercise Recovery: a Systematic Review and Meta-analysis

“…This finding was preserved when contextual factors were explored using metaregression analysis (Table 4). It is also consistent with results from previous meta-analyses indicating that coingestion of PRO with CHO during short-term recovery does not improve short-term muscle glycogen resynthesis [67] or subsequent exercise performance [68].…”

“…The authors hypothesised that the lower rate of muscle glycogen re-synthesis observed in the PRO trial may be due to AA triggering protein synthesis, resulting in glucose being oxidised to support the energy requirement for this process in place of glycogen storage [56]. Nonetheless, while the overall effect of our analysis suggests that co-ingesting PRO with CHO does not provide any benefit beyond that of CHO alone to muscle glycogen restoration (even when CHO intake is Table 2 The influence of contextual factors on the mean difference in rate of muscle glycogen re-synthesis (analysed via restricted maximum likelihood, simple meta-regression) for CHO vs. control treatments A recent meta-analysis [67] similar to the present study reported a significant main effect (favouring CHO+PRO over CHO) on muscle glycogen re-synthesis rate when the energy intake was not matched between treatments (non-isocaloric). This finding contrasts the results of the present study (Table 4).…”

“…The discrepancy between findings may be due to a number of factors. Firstly, different effect estimates were used between studies; we reported the mean difference for ease of interpretation [70], whereas Margolis et al [67] reported Hedges' g. Secondly, studies employing 13 C-MRS techniques to determine muscle glycogen concentration were included in the previous study, while our results are based on studies using muscle tissue samples for glycogen analysis (as a means of reducing methodological heterogeneity). Thirdly, the previous metaanalysis included studies that provided CHO+PRO in combination with fat, and in some circumstances, the fat content was not matched between treatments [26,47,51,71,72].…”

Renal Rehabilitation: Exercise Intervention and Nutritional Support in Dialysis Patients

“…Therefore, milk protein is expected to both promote and sustain muscle protein synthesis. A recent meta-analysis reported that glycogen synthesis rates are enhanced when carbohydrates and protein are co-ingested after exercise compared to carbohydrates only, when the added energy of protein is consumed in addition to, not in place of, carbohydrates, suggesting the importance of an increase in the energy intake [ 64 ]. It is well known that modulating postexercise nutrition is an effective approach to enhance the replenishment of muscle glycogen stores.…”

The Validity of Ultrasound Technology in Providing an Indirect Estimate of Muscle Glycogen Concentrations Is Equivocal

“…We acknowledge that the collection of biopsy samples from adjacent, but non-identical sites, or sites from contra-lateral limbs in scenarios involving symmetrical exercise protocols, may contribute to the technical error of measurement involved with chemical determination of muscle glycogen stores. Nevertheless, it is the basis of a robust literature involving many hundreds of studies, which have determined resting muscle glycogen concentrations in different populations [ 36 ], glycogen utilisation during exercise [ 1 , 53 ], and glycogen synthesis in response to diet [ 19 , 54 , 55 ].…”