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Dextrose vs. Maltodextrin Revisited

Recently Eric Cressey posted about some research that showed that maltodextrin is better than dextrose at replenishing glycogen stores. However, the following abstract seems to show the opposite (even though that comparison wasn’t the main focus of the study), and rather dramatically. I’d love it if I could get someone’s input on the following who’s better versed at interpreting such things than I am.

Int J Sports Med 1996 Jul;17(5):373-8

The influence of starch structure on glycogen resynthesis and subsequent cycling performance.

Jozsi AC, Trappe TA, Starling RD, Goodpaster B, Trappe SW, Fink WJ, Costill DL.

Human Performance Laboratory, Ball State University, Muncie, Indiana 47306, USA.

The present study was designed to evaluate the influence of starch structure on muscle glycogen resynthesis and cycling performance. Eight male cyclists (22 +/- 1 yr) completed an exercise protocol (DP) to decrease vastus lateralis glycogen concentration. This exercise consisted of 60 min cycling at 75% VO2max, followed by six 1-min sprints at approximately 125% VO2max with 1 min rest intervals. In the 12 hr after the exercise each subject consumed approximately 3000 kcal (65:20:15% carbohydrate, fat and protein). All of the carbohydrate (CHO) consumed was derived from one of four solutions; 1) glucose, 2) maltodextrin (glucose polymer), 3) waxy starch (100% amylopectin), or 4) resistant starch (100% amylose). Muscle biopsies were taken from the vastus lateralis muscle after DP and 24 hr later to determine glycogen concentrations. A 30 min cycling time trial (TT) was performed following the 24 hr post-DP muscle biopsy to examine the influence of the feeding regimen on total work output. The post-DP glycogen concentrations were similar among the four trials, ranging from 220.3 +/- 29.2 to 264 +/- 48.3 mmol.kg-1 dry weight (d.w.) muscle. Twenty-four hours after DP, muscle glycogen concentration had increased less (p < 0.05) in the resistant starch trial (+90.8 +/- 12.8 mmol.kg-1 d.w.) than in the glucose (+197.7 +/- 31.6 mmol.kg-1 d.w.), maltodextrin (+136.7 +/- 24.5 mmol.kg-1 d.w.) and waxy starch (+171.8 +/- 37.1 mmol.kg-1 d.w.) trials. There were no differences in total work output during the TT, or blood lactate concentration immediately following the TT in any of the CHO trials. In summary, glycogen resynthesis was attenuated following ingestion of starch with a high amylose content, relative to amylopectin or glucose; however, short duration time trial performance was unaffected.

Bump for some love.

Zev, man, I just wanted to give you some much-deserved love, bro:-)

It comes as no surprise that the amylose CHO resulted in the lowest glycogen resynthesis. The ratio of amylopectin to amylose is an important indicator of the glycemic (and presumably the insulinemic) response of to a carbohydrate.

Amylopectin is hydrolyzed more rapidly than amylose, and thus the aforementioned response.

The difference between glucose and maltodextrin appears to be significant here, though, indicating that glucose provides more rapid glycogen resynthesis.

This is just one study, though, and I think that you’ll find rates of glycogen resynthesis much closer between the two when analyzing all the research.

There’s a benefit to adding both to your liquid during and post-workout meals. The maltodextrin should be broken down slightly slower than the glucose, and thus, as soon as the glucose is transported across the muscle cell membrane, the glucose from the maltodextrin will be there to be transported next. This would be opposed to straight-up glucose, which there might be a risk of saturation.

Timbo wrote: “The difference between glucose and maltodextrin appears to be significant here, though, indicating that glucose provides more rapid glycogen resynthesis.”

Yeah, that’s what piqued my interest. Cress posted a few studies a little while ago that showed the opposite.

“This is just one study, though, and I think that you’ll find rates of glycogen resynthesis much closer between the two when analyzing all the research.”

Prolly so, although this study is more in line with my intutions (which we all know are worth jack shit) than the ones that show that malto is superior to dextrose for glycogen replenishment.