Muscle glycogen storage following prolonged exercise: effect of the
co-ingestion of fat and protein with carbohydrate feedings.
Burke, Louise M, Greg R Collier, Susan K Beasley, Peter G Davis, Peter
A Fricker, Prue Heeley, Ken Walder, Mark Hargreaves.
Sports Science/Sports Medicine, Australian Institute of Sport, ACT
2616, School of Nutrition and Public Health, Deakin University,
Geelong 3217, and Department of Physiology, the University of
Melbourne, Parkville 3052, Australia
APStracts 2:0077A, 1995.
Dietary guidelines for achieving optimal muscle glycogen storage
following prolonged exercise have been given in terms of absolute
carbohydrate (CHO) intake (8-10g.kg-1.24hr-1). However, it is of
further interest to determine whether addition of fat and protein to
carbohydrate feedings affects muscle glycogen storage. Eight well
-trained triathletes (23.1 + 2.0 yrs; 74.0 + 3.4 kg; V02 peak = 4.7 +
0.4 L.min-1, mean + S.E.) undertook an exercise trial (2 hours at 75%
V02peak, followed by four 30 second sprints) on three occasions, each
one week apart. For 24 hours after each trial subjects rested and
were assigned to the following diets in randomised order: Control
diet (C) = high glycemic index CHO foods, CHO = 7g.kg-1.24hr-1; Added
fat and protein diet (FP) = Control diet + 1.6g.kg-1.24hr-1 fat +
1.2g.kg-1.24hr-1 protein; Matched energy diet (ME) = Control diet +
4.8g.kg-1.24hr-1 additional CHO (Polycose) to match additional energy
in FP diet. Meals were eaten at t=0,4,8 and 21 hours of recovery. The
total post-prandial incremental plasma glucose area was significantly
reduced following the FP diet (p<0.05). Serum free fatty acid and
plasma triglyceride responses were significantly elevated during the
FP trial (p<0.05). There were no differences between trials in muscle
glycogen storage over 24 hrs (C: 85.8 + 2.7 mmol.kg-1 wet weight; FP:
80.5 + 8.2; ME: 87.9 + 7.0). Results of this study suggest that the
addition of fat and protein to a recovery diet does not alter
glycogen storage over 24 hours, provided CHO intake is adequate.
Received 4 August 1994; accepted in final form 7 February 1995.
APS Manuscript Number A808-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 10 March 1995.