TY - JOUR
T1 - Protein Supplementation Does Not Augment Adaptations to Endurance Exercise Training
AU - Jonvik, Kristin L.
AU - Paulussen, Kevin J.M.
AU - Danen, Shiannah L.
AU - Ceelen, Ingrid J.M.
AU - Horstman, Astrid M.
AU - Wardenaar, Floris C.
AU - Van Loon, Luc U.C.J.C.
AU - Van Dijk, Jan Willem
N1 - Funding Information:
This project was funded by the Dutch Ministry of Economic Affairs (Topsector Agri&Food), award number AF16501 (PPS Allowance). K. L. J., K. J. M. P., S. L. D., and I. J. M. C. declare that they have no conflict of interest. F. C. W., L. J. C. v. L., and J.-W. v. D. have received research grants, consulting fees, and/or speaking honoraria from FrieslandCampina. L. J. C. v. L. has received research grants, consulting fees, and speaking honoraria from Pepsico/Gatorade. AMHH is an employee at FrieslandCampina.
Publisher Copyright:
© 2019 by the American College of Sports Medicine.
PY - 2019/10/1
Y1 - 2019/10/1
N2 - 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 (VO2max) 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; VO2max, 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, VO2max 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 VO2max (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.
AB - 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 (VO2max) 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; VO2max, 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, VO2max 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 VO2max (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.
KW - ENDURANCE EXERCISE
KW - ENDURANCE PERFORMANCE
KW - MUSCULAR ENDURANCE
KW - PROTEIN INTAKE
KW - STRENGTH
KW - VO
UR - http://www.scopus.com/inward/record.url?scp=85072233168&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85072233168&partnerID=8YFLogxK
U2 - 10.1249/MSS.0000000000002028
DO - 10.1249/MSS.0000000000002028
M3 - Article
C2 - 31525168
AN - SCOPUS:85072233168
SN - 0195-9131
VL - 51
SP - 2041
EP - 2049
JO - Medicine and science in sports and exercise
JF - Medicine and science in sports and exercise
IS - 10
ER -