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Cited by 41Muscle metabolism and nutritionSports Performance and TrainingCardiovascular and exercise physiology

A Whey-Supplemented, High-Protein Diet versus a High-Carbohydrate Diet: Effects on Endurance Cycling Performance

Macdermid, Paul W., Stannard, Stephen R.·2006·International Journal of Sport Nutrition and Exercise Metabolism
DOI 10.1123/ijsnem.16.1.65
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Abstract

This study compared a training diet recommended for endurance athletes (H-CHO) with an isoenergetic high protein (whey supplemented), moderate carbohydrate (H-Pro) diet on endurance cycling performance. Over two separate 7-d periods subjects (n = 7) ingested either H-CHO (7.9 +/- 1.9 g x kg(-1) x d(-1) carbohydrate; 1.2 +/- 0.3 g x kg(-1) x d(-1) fat; 1.3 +/- 0.4 g x kg(-1) x d(-1) protein) or H-Pro (4.9 +/- 1.8 g x kg(-1) x d(-1); 1.3 +/- 0.3 g x kg(-1) x d(-1); 3.3 +/- 0.4 g x kg(-1) x d(-1)) diet in a randomized, balanced order. On day 8 subjects cycled (self-paced) for a body weight dependent (60 kJ/bm) amount of work. No differences occurred between energy intake (P = 0.422) or fat intake (P = 0.390) during the two dietary conditions. Performance was significantly (P = 0.010) impaired following H-Pro (153 +/- 36) compared with H-CHO (127 +/- 34 min). No differences between treatments were observed for physiological measures taken during the performance trials. These results indicate an ergolytic effect of a 7-d high protein diet on self-paced endurance cycling performance.

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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 [2]

  • Increasing protein intakes above recommended intakes does not enhance endurance performance.

    “Although the number of investigations is limited, it appears as if increasing protein intakes above recommended intakes does not enhance endurance performance [2, 4, 5].”

    From International Society of Sports Nutrition Position Stand: protein and exercise (2017) · cites this paper as [2]

  • 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 [2]

  • Low carbohydrate availability ranges have not been established based on these criteria for carbohydrate availability, and many studies continue to report carbohydrate intake, using low carbohydrate intake to define intake below current recommendations.

    “Nonetheless, LCA ranges have not been established based on these criteria for CHO availability, and many studies continue to report CHO intake, using low CHO intake to define intake below current recommendations [34,35,36,37,38,39,40,41,42,43].”

    From Considerations of Low Carbohydrate Availability (LCA) to Relative Energy Deficiency in Sport (RED-S) in Female Endurance Athletes: A Narrative Review (2023) · cites this paper as [37]

  • In male endurance-trained cyclists, consuming a higher protein/lower CHO diet (3.3 g protein/kg BW/d and 5.9 g CHO/kg BW/d) resulted in significantly worse time trial performance compared to consuming a typical endurance athlete diet (1.3 g protein/kg BW/d and 7.9 g CHO/kg BW/d), which saw no significant change from baseline.

    “In a study of male, endurance-trained cyclists, those consuming a higher protein/lower CHO diet (3.3 g protein/kg BW/d and 5.9 g CHO/kg BW/d) performed significantly worse on a time trial compared to those consuming a diet more representative of the typical endurance athlete diet (1.3 g protein/kg BW/d and 7.9 g CHO/kg BW/d) who saw no significant change in performance from the baseline [37].”

    From Considerations of Low Carbohydrate Availability (LCA) to Relative Energy Deficiency in Sport (RED-S) in Female Endurance Athletes: A Narrative Review (2023) · cites this paper as [37]

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Authors
Macdermid, P. W., & Stannard, S. R.
Affiliations
Universal College of Learning (NZ)
ORCID
Venue
International Journal of Sport Nutrition and Exercise Metabolism
Publisher
Human Kinetics
Published
2006-02
Volume
16
Issue
1
Pages
65-77
ISSN
  • 1526-484X (ISSN-L)
  • 1543-2742
DOI
10.1123/ijsnem.16.1.65
OpenAlex
W1540945054
Cited by
41
References
22
Citations by year
2026: 1 · 2025: 2 · 2024: 1 · 2023: 2 · 2022: 1 · 2021: 1 · 2020: 1 · 2019: 2 · 2018: 3 · 2017: 2 · 2016: 2 · 2014: 3 · 2013: 3 · 2012: 2
FWCI
1.38
Type
journal article
Language
en
Open access
closed
Locations
  • International Journal of Sport Nutrition and Exercise Metabolism (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 › Complementary and alternative medicine › Cardiovascular and exercise physiology
Keywords
whey protein supplementation, high-protein diet, high-carbohydrate diet, endurance cycling performance, endurance athletes, self-paced cycling, protein intake, energy intake, dietary fat intake
MeSH terms
Whey Proteins, Adult, Bicycling, Blood Glucose, Energy Intake, Diet, Dietary Carbohydrates, Dietary Proteins, Energy Metabolism, Exercise Test, Humans, Milk Proteins, Physical Endurance, Respiratory Function Tests, Time Factors, Dietary Supplements

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