[Nelson]

Burke, L. M., G. R. Collier, S. K. Beasley, P. G. Davis, P. A. Fricker, P. Heeley, K. Walder, and M. Hargreaves. Effect of coingestion of fat and protein with carbohydrate feedings on muscle glycogen storage. Journal of Applied Physiology 78: 2187-2192, 1995.

abstract

Dietary guidelines for achieving optimal muscle glycogen storage after prolonged exercise have been given in terms of absolute carbohydrate (CHO) intake (8-10 g.kg-1.day-1). However, it is of further interest to determine whether the addition of fat and protein to carbohydrate feedings affects muscle glycogen storage. Eight well-trained triathletes [23.1 +/- 2.0 (SE) yr; 74.0 +/- 3.4 kg; peak O2 consumption = 4.7 +/- 0.4 l/min] undertook an exercise trial (2 h at 75% peak O2 consumption, followed by four 30-s sprints) on three occasions, each 1 wk apart. For 24 h after each trial, the subjects rested and were assigned to the following diets in randomized order: control (C) diet (high glycemic index CHO foods; CHO = 7 g.kg-1.day-1), added fat and protein (FP) diet (C diet + 1.6 g.kg-1.day-1 fat + 1.2 g.kg-1.day-1 protein), and matched-energy diet [C diet + 4.8 g.kg-1.day-1 additional CHO (Polycose) to match the additional energy in the FP diet]. Meals were eaten at t = 0, 4, 8, and 21 h of recovery. The total postprandial incremental plasma glucose area was significantly reduced after 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 h (C, 85.8 +/- 2.7 mmol/kg wet wt; FP, 80.5 +/- 8.2 mmol/kg wet wt; matched-energy, 87.9 +/- 7.0 mmol/kg wet wt).

[Draven]

The problem with this is the included fat. Fat slows digestion which also slows the release of glucose into the blood stream. This explains the total postprandial incremental plasma glucose levels being lower than the CHO only group. I'd be curious to see a study on glycogen storage where a CHO and CHO/Pro combo where studied without the added fat. I know lots exist where glycogen resysnthesis is study but not storage. It could be that the additional of protein WOULD increase storage but due the addition of fat it negated the effects by slowing the release of glucose. Maybe?

[Kruger]

I think you guys should worry about the RATE at which resynthesis occurs, not the amount of glycogen stored. More dose not mean faster.

[motleybreu]

good point bobo