ArticleJournal of the International Society of Sports Nutrition2020
Effects of protein intake prior to carbohydrate-restricted endurance exercise: a randomized crossover trial.
Article in Journal of the International Society of Sports Nutrition, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 2 registered trials, which are not on this map. Cited by 10 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Identification of New Serum Markers for Detection of Abuse With Erythropoietin
Nutritional Strategies for Optimizing Adaptations and Recovery Following Training 'Low'.
Who cites it
10 citing papers in PubMed, 1 synthesis or guideline pooled it, 16 citations in OpenAlex.
- Muscle Protein Synthesis Responses Following Aerobic-Based Exercise or High-Intensity Interval Training with or Without Protein Ingestion: A Systematic Review.Sports medicine (Auckland, N.Z.) · 2022Pooled it
- Whey protein intakes up to 0.4g/kg body mass are well tolerated before a 10km run at 85% of race pace: a clinical trial.Journal of the International Society of Sports Nutrition · 2026Trial
- Substituting Carbohydrate at Lunch for Added Protein Increases Fat Oxidation During Subsequent Exercise in Healthy Males.The Journal of clinical endocrinology and metabolism · 2025Trial
- Initiating aerobic exercise with low glycogen content reduces markers of myogenesis but not mTORC1 signaling.Journal of the International Society of Sports Nutrition · 2021Trial
- Trial
- Supplement with whey protein hydrolysate in contrast to carbohydrate supports mitochondrial adaptations in trained runners.Journal of the International Society of Sports Nutrition · 2020Trial
- Protein Nutrition for Endurance Athletes: A Metabolic Focus on Promoting Recovery and Training Adaptation.Sports medicine (Auckland, N.Z.) · 2025Review
- Factors Influencing Substrate Oxidation During Submaximal Cycling: A Modelling Analysis.Sports medicine (Auckland, N.Z.) · 2022Article
- Serum Branched-Chain Amino Acid Metabolites Increase in Males When Aerobic Exercise Is Initiated with Low Muscle Glycogen.Metabolites · 2021Article
- What Should I Eat before Exercise? Pre-Exercise Nutrition and the Response to Endurance Exercise: Current Prospective and Future Directions.Nutrients · 2020Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
12 authors at 4 institutions in 2 countries.
Funding
Abstract
backgroundDeliberately training with reduced carbohydrate availability, a paradigm coined training low, has shown to promote adaptations associated with improved aerobic capacity. In this context researchers have proposed that protein may be ingested prior to training as a means to enhance the protein balance during exercise without spoiling the effect of the low carbohydrate availability. Accordingly, this is being practiced by world class athletes. However, the effect of protein intake on muscle protein metabolism during training low has not been studied. This study aimed to examine if protein intake prior to exercise with reduced carbohydrate stores benefits muscle protein metabolism in exercising and non-exercising muscles.
methodsNine well-trained subjects completed two trials in random order both of which included a high-intensity interval ergometer bike ride (day 1), a morning (day 2) steady state ride (90 min at 65% VO
resultsForearm protein net balance was not different from zero during 90ss exercise (nmol/100 ml/min, PLA: 0.5 ± 2.6; WPH: 1.8, ± 3.3) but negative during the 4 h recovery (nmol/100 ml/min, PLA: - 9.7 ± 4.6; WPH: - 8.7 ± 6.5); no interaction (P = 0.5) or main effect of beverage (P = 0.11) was observed. Vastus lateralis myofibrillar protein synthesis rates were increased during 90ss exercise (+ 0.02 ± 0.02%/h) and recovery (+ 0.02 ± 0.02%/h); no interaction (P = 0.3) or main effect of beverage (P = 0.3) was observed.
conclusionWe conclude that protein ingestion prior to endurance exercise in the energy- and carbohydrate-restricted state does not increase myofibrillar protein synthesis or improve net protein balance in the exercising and non-exercising muscles, respectively, during and in the hours after exercise compared to ingestion of a non-caloric control.
trial registrationclinicaltrials.gov, NCT01320449. Registered 10 May 2017 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03147001.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.