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Protein supplementation does not augment adaptations to endurance exercise training
Jonvik, Kristin L. Paulussen, Kevin J. M. Danen, Shiannah L. Ceelen, Ingrid J. M. Horstman, Astrid M. H. Wardenaar, Floris C. Van Loon, Luc J. C. Willem van Dijk, Jan
Jonvik, Kristin L.
Paulussen, Kevin J. M.
Danen, Shiannah L.
Ceelen, Ingrid J. M.
Horstman, Astrid M. H.
Wardenaar, Floris C.
Van Loon, Luc J. C.
Willem van Dijk, Jan
Abstract
Introduction Recently, it has been speculated that protein supplementation may further augment the adaptations to chronic endurance exercise training. We assessed the effect of protein supplementation during chronic endurance exercise training on whole-body oxidative capacity (V˙O2max) and endurance exercise performance. Methods In this double-blind, randomized, parallel placebo-controlled trial, 60 recreationally active males (age, 27 ± 6 yr; body mass index, 23.8 ± 2.6 kg·m−2; V˙O2max, 47 ± 6 mL·min−1·kg−1) were subjected to 12 wk of triweekly endurance exercise training. After each session and each night before sleep, participants ingested either a protein supplement (PRO; 28.7 g casein protein) or an isoenergetic carbohydrate placebo (PLA). Before and after the 12 wk of training, V˙O2max and endurance exercise performance (~10-km time trial) were assessed on a cycle ergometer. Muscular endurance (total workload achieved during 30 reciprocal isokinetic contractions) was assessed by isokinetic dynamometry and body composition by dual-energy x-ray absorptiometry. Mixed-model ANOVA was applied to assess whether training adaptations differed between groups. Results Endurance exercise training induced an 11% ± 6% increase in V˙O2max (time effect, P < 0.0001), with no differences between groups (PRO, 48 ± 6 to 53 ± 7 mL·min−1·kg−1; PLA, 46 ± 5 to 51 ± 6 mL·min−1·kg−1; time–treatment interaction, P = 0.50). Time to complete the time trial was reduced by 14% ± 7% (time effect, P < 0.0001), with no differences between groups (time–treatment interaction, P = 0.15). Muscular endurance increased by 6% ± 7% (time effect, P < 0.0001), with no differences between groups (time–treatment interaction, P = 0.84). Leg lean mass showed an increase after training (P < 0.0001), which tended to be greater in PRO compared with PLA (0.5 ± 0.7 vs 0.2 ± 0.6 kg, respectively; time–treatment interaction, P = 0.073). Conclusion Protein supplementation after exercise and before sleep does not further augment the gains in whole-body oxidative capacity and endurance exercise performance after chronic endurance exercise training in recreationally active, healthy young males.
Keywords
endurance exercise, endurance performance, muscular endurance, strength, protein intake
Date
2019
Type
Journal article
Journal
Medicine and Science in Sports and Exercise
Book
Volume
51
Issue
10
Page Range
2041-2049
Article Number
ACU Department
Collections
Relation URI
Source URL
Event URL
Open Access Status
Open access
License
CC BY-NC-ND 4.0
File Access
Open