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The effects of carbohydrate and protein hydrolysate co-ingestion upon exercise metabolism and cycling performance

Page, Richard


Richard Page


Jason Siegler

Adrian Wayne Midgley


The ergogenic effects of acute carbohydrate (CHO) supplementation during prolonged exercise are well established. Recently, a number of studies have examined the potential for the inclusion of protein to further augment these efficacious effects. However, observations at present remain equivocal. Furthermore, there is currently a dearth of knowledge regarding the potential physiologic influences of specific protein sources. Therefore, the purpose of the current study was to determine the efficacy of adding whey protein (CHO-PRO) and hydrolysed marine peptides (CHO-PRO-PEP) to a CHO solution when compared to an equally energetic CHO only beverage. Following an initial familiarisation, 12 recreationally active male volunteers performed three randomised, double blind trials. The trials consisted of a 90-minute steady-state cycle preload corresponding to 50% of predetermined maximal power output, followed by a 5 km time-trial. From the onset of exercise and at 15-minute intervals during the initial preload, participants ingested 180 ml of either: CHO (67¯¹ of maltodextrin); CHO-PRO (53.1¯¹ of maltodextrin, 13.6¯¹ of whey protein concentrate) or CHO-PRO-PEP (53.1¯¹ of maltodextrin, 11.0¯¹ of whey protein concentrate and 2.4¯¹ of protein hydrolysate extracted from salmon). Physiological measures including heart rate, blood glucose and blood lactate were also acquired at 15-minute intervals concomitant to expired gas analysis. No significant differences were observed in time-to-complete the 5 km time-trial regardless of the solution ingested (455.49 ± 16.10; 455.57 ± 18.09 and 454.83 ± 20.75 seconds for CHO, CHO-PRO and CHO-PRO-PEP respectively, p = 0.97). Average and peak power output also demonstrated no statistical significance between treatments (p = 0.71 and p = 0.44, respectively). Conversely, significant interaction effects (condition × time) were apparent for both blood lactate (p = 0.02) and the respiratory exchange ratio (p = 0.007). Heart rate also demonstrated a significant main effect for condition (p = 0.047). No other physiological parameters were significantly different between conditions. This data therefore suggests that CHO-PRO and CHO-PRO-PEP supplementation provide no additional performance enhancing effects in comparison to a typical CHO only solution. However, the inclusion of protein from marine sources within a CHO solution may influence substrate utilisation during prolonged steady-state exercise.


Page, R. (2012). The effects of carbohydrate and protein hydrolysate co-ingestion upon exercise metabolism and cycling performance. (Thesis). University of Hull. Retrieved from

Thesis Type Thesis
Deposit Date Jan 15, 2013
Publicly Available Date Feb 22, 2023
Keywords Sport science
Public URL
Additional Information Department of Sport, Health and Exercise Science, The University of Hull
Award Date Apr 1, 2012


Thesis (707 Kb)

Copyright Statement
© 2012 Page, Richard. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.

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