Plus de protéines = plus d'endurance ?

[Nutrimuscle-Conseils]

Protein supplementation increases adaptations to endurance training: A systematic review and meta-analysis
Yen-Nung Lin Clinical Nutrition Volume 40, Issue 5, May 2021, Pages 3123-3132

Background
Trials that assessed the impact of protein supplementation on endurance training adaptations have reported conflicting findings.

Objective
To determine the impact of protein supplementation during chronic endurance training on aerobic capacity, body composition and exercise performance in healthy and clinical populations.

Design
A systematic database search was conducted for randomised controlled trials addressing the effects of protein supplementation during endurance training on aerobic capacity, body composition and exercise performance in PubMed, Embase, Web of Science, and CINAHL. Meta-analyses were performed to outline the overall effects of protein supplementation with all studies containing endurance training components. The effects of endurance training and add-on effects of protein supplementation were evaluated by the meta-analyses with endurance training-focused studies.

Results
Nineteen studies and 1162 participants contributed to the analyses. Compared with the control group, the protein supplementation group demonstrated greater improvements in aerobic capacity measured by mixed peak oxygen uptake (V̇O2peak) and peak workload power (Wpeak) (standardised mean difference [SMD] = 0.36, 95% confidence interval [CI]: 0.05 to 0.67), and V̇O2peak (mean difference [MD] = 0.89 mL‧kg−1‧min−1, 95% CI: 0.07 to 1.70); had a greater lean mass gain (MD = 0.32 kg, 95% CI: 0.07 to 0.58); and had a greater improvement in time trial performance (MD = −29.1s, 95% CI:-55.3 to −3.0). Secondary analyses showed that, in addition to the substantial improvement in V̇O2peak (MD = 3.67 mL‧kg−1‧min−1, 95% CI: 2.32 to 5.03) attributed to endurance training, protein supplementation provided an additional 26.4% gain in V̇O2peak (MD = 0.97 mL‧kg−1‧min−1, 95% CI: −0.03 to 1.97).

Conclusion
Protein supplementation further increased aerobic capacity, stimulated lean mass gain, and improved time trial performance during chronic endurance training in healthy and clinical populations.

[Nutrimuscle-Conseils]

Carbohydrate-Restricted Exercise With Protein Increases Self-Selected Training Intensity in Female Cyclists but Not Male Runners and Cyclists
Oosthuyse, Tanja Journal of Strength and Conditioning Research: June 2021 - Volume 35 - Issue 6 - p 1547-1558

Carbohydrate-restricted training challenges preservation of euglycemia and exercise intensity that precludes ergogenic gains, necessitating countering strategies. We investigated the efficacy of ingesting casein protein hydrolysate in overnight-fasted male runners, male cyclists, and female cyclists. Twenty-four overnight-fasted athletes ingested 15.8 g·h−1 casein hydrolysate or placebo-water during exercise (60–80 minutes) comprising an incremental test to exhaustion, steady-state exercise (70% Vmax or 60% peak power output, 87 ± 4% HRmax), and 20-minute time trial (TT) in a double-blind randomized crossover design, with p < 0.05 accepted as significant. Ingesting protein vs. placebo increased metabolic demand {oxygen consumption, +4.7% (95% confidence interval [CI] ± 4%), p = 0.0297; +3.2% (95% CI ± 3.4%), p = 0.061}, heart rate (p = 0.0083; p = 0.007) and rating of perceived exertion (RPE) (p = 0.0266; p = 0.0163) in male cyclists and runners, respectively, but not female cyclists. Protein vs. placebo increased carbohydrate oxidation (+0.26 [95% CI ± 0.13] g·min−1, p = 0.0007) in female cyclists alone. Cyclists reported +2 ± 1 higher RPE than runners (p = 0.0062). Glycemia was maintained only in runners and increased with protein vs. placebo after 20 minutes of steady-state exercise (+0.63 [95% CI ± 0.56] mmol·L−1, p = 0.0285). TT performance with protein vs. placebo ingestion was modestly compromised in runners (−2.8% [95% CI ± 2.2%], p = 0.0018), unchanged in male cyclists (+1.9% [95% CI ± 5.6%], p = 0.5794), and modestly improved in female cyclists (+2.5% [95% CI ± 1.8%], p = 0.0164). Casein hydrolysate ingestion during moderate to hard carbohydrate-restricted exercise increases glycemia in runners, but not cyclists. Casein hydrolysate increases metabolic demand in male athletes and carbohydrate oxidation in female cyclists and is suitable for improving carbohydrate-restricted training intensity in female but not male endurance athletes.

[Nutrimuscle-Diététique]

Traduction de l'étude

L'exercice restreint en glucides avec des protéines augmente l'intensité d'entraînement auto-sélectionnée chez les cyclistes féminines, mais pas les coureurs et cyclistes masculins
Oosthuyse, Tanja Journal of Strength and Conditioning Research : juin 2021 - Volume 35 - Numéro 6 - p 1547-1558

L'entraînement restreint en glucides remet en cause la préservation de l'euglycémie et l'intensité de l'exercice qui empêchent les gains ergogéniques, ce qui nécessite des stratégies de lutte. Nous avons étudié l'efficacité de l'ingestion d'hydrolysat de protéines de caséine chez des coureurs à jeun, des cyclistes et des cyclistes. Vingt-quatre athlètes à jeun pendant la nuit ont ingéré 15,8 g · h − 1 d'hydrolysat de caséine ou de placebo-eau pendant l'exercice (60 à 80 minutes) comprenant un test progressif jusqu'à l'épuisement, exercice à l'état d'équilibre (70% Vmax ou 60% de puissance de pointe, 87 ± 4% HRmax), et essai contre la montre de 20 minutes (TT) dans un plan croisé randomisé en double aveugle, avec p <0,05 accepté comme significatif. L'ingestion de protéines par rapport au placebo a augmenté la demande métabolique {consommation d'oxygène, +4,7 % (intervalle de confiance à 95 % [IC] ± 4 %), p = 0,0297 ; +3,2 % (IC 95 % ± 3,4 %), p = 0,061}, fréquence cardiaque (p = 0,0083 ; p = 0,007) et évaluation de l'effort perçu (RPE) (p = 0,0266 ; p = 0,0163) chez les hommes cyclistes et coureurs , respectivement, mais pas les cyclistes féminines. Les protéines par rapport au placebo ont augmenté l'oxydation des glucides (+0,26 [IC à 95 % ± 0,13] g·min−1, p = 0,0007) chez les cyclistes féminines seules. Les cyclistes ont rapporté +2 ± 1 RPE plus élevé que les coureurs (p = 0,0062). La glycémie s'est maintenue uniquement chez les coureurs et a augmenté avec les protéines versus placebo après 20 minutes d'exercice à l'état d'équilibre (+0,63 [IC 95 % ± 0,56] mmol·L−1, p = 0,0285). Les performances du TT avec l'ingestion de protéines par rapport à un placebo ont été légèrement compromises chez les coureurs (−2,8 % [IC à 95 % ± 2,2 %], p = 0,0018), inchangées chez les cyclistes masculins (+ 1,9 % [IC à 95 % ± 5,6 %], p = 0,5794), et légèrement améliorée chez les cyclistes féminines (+2,5 % [IC 95 % ± 1,8 %], p = 0,0164). L'ingestion d'hydrolysat de caséine pendant un exercice modéré à dur avec restriction en glucides augmente la glycémie chez les coureurs, mais pas chez les cyclistes. L'hydrolysat de caséine augmente la demande métabolique chez les athlètes masculins et l'oxydation des glucides chez les cyclistes féminines et convient pour améliorer l'intensité de l'entraînement restreint en glucides chez les athlètes d'endurance féminins mais pas masculins.