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Cited by 118Muscle metabolism and nutritionSports Performance and TrainingThermoregulation and physiological responses

Failure of Protein to Improve Time Trial Performance when Added to a Sports Drink

VAN ESSEN, MARTIN, GIBALA, MARTIN J.·2006·Medicine & Science in Sports & Exercise
DOI 10.1249/01.mss.0000228958.82968.0a
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Abstract

INTRODUCTION: Recent studies have reported that adding approximately 2% protein to a carbohydrate sports drink increased cycle endurance capacity compared with carbohydrate alone. However, the practical implications of these studies work are hampered by the following limitations: (a) the rate of carbohydrate ingestion was less than what is considered optimal for endurance performance, and (b) the performance test (exercise time to fatigue) did not mimic the way in which athletes typically compete (i.e., a race in which a fixed distance or set amount of work is performed as quickly as possible). PURPOSE: We tested the hypothesis that adding 2% protein to a 6% carbohydrate drink (CHO-PRO) would improve 80-km cycling time trial performance, as compared with a 6% carbohydrate drink (CHO) and a nonenergetic sweetened placebo (PLAC). METHODS: Ten trained male cyclists (24 +/- 2 yr; VO2peak = 63 +/- 2 mL.kg(-1).min(-1); mean +/- SE) performed an 80-km laboratory time trial (TT) on three occasions separated by 7 d. In a double-blind crossover manner, subjects ingested CHO-PRO, CHO, or PLAC at a rate of 250 mL every 15 min with no temporal, verbal, or physiological feedback. RESULTS: Time to complete the TT was 4.4% lower (P < 0.002) during CHO (135 +/- 9 min) and CHO-PRO (135 +/- 9) compared with PLAC (141 +/- 10), with no difference between CHO and CHO-PRO (P = 0.92). CONCLUSION: Ingesting 6% carbohydrate at a rate of 1 L.h(-1) (60 g.h(-1)) improved an 80-km TT performance in trained male cyclists. However, adding 2% protein to a 6% carbohydrate drink provided no additional performance benefit during a task that closely simulated the manner in which athletes typically compete.

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  • Added protein does not appear to improve endurance performance when given for several days, weeks, or immediately prior to and during endurance exercise.

    “In conclusion, added protein does not appear to improve endurance performance when given for several days, weeks, or immediately prior to and during endurance exercise.”

    From International Society of Sports Nutrition Position Stand: protein and exercise (2017) · cites this paper as [9]

  • When adequate carbohydrate is delivered, adding protein to carbohydrate does not appear to improve endurance performance over the course of a few days or weeks.

    “When adequate carbohydrate is delivered, adding protein to carbohydrate does not appear to improve endurance performance over the course of a few days or weeks.”

    From International Society of Sports Nutrition Position Stand: protein and exercise (2017) · cites this paper as [9]

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Authors
VAN ESSEN, M., & GIBALA, M. J.
Affiliations
McMaster University (CA)
ORCID
GIBALA, MARTIN J.
Venue
Medicine & Science in Sports & Exercise
Publisher
Ovid Technologies (Wolters Kluwer Health)
Published
2006-08
Volume
38
Issue
8
Pages
1476-1483
ISSN
0195-9131 (ISSN-L)
DOI
10.1249/01.mss.0000228958.82968.0a
OpenAlex
W2093997012
Cited by
118
References
32
Citations by year
2026: 1 · 2025: 3 · 2024: 2 · 2023: 1 · 2021: 6 · 2020: 3 · 2019: 2 · 2018: 4 · 2017: 2 · 2016: 11 · 2015: 3 · 2014: 5 · 2013: 15 · 2012: 6
FWCI
3.87
Type
journal article
Language
en
Open access
closed
Locations
  • Medicine & Science in Sports & Exercise (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
  • Health Sciences › Medicine › Physiology › Thermoregulation and physiological responses
Keywords
protein supplementation, sports drinks, carbohydrate intake, time trial performance, cycling, endurance performance, trained cyclists
MeSH terms
Adult, Analysis of Variance, Beverages, Bicycling, Blood Glucose, Dietary Carbohydrates, Double-Blind Method, Fatty Acids, Nonesterified, Humans, Insulin, Male, Physical Endurance, Proteins, Psychomotor Performance, Time Factors, Treatment Failure, Cross-Over Studies, Lactic Acid

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