Carbohydrate ingestion augments creatine retention during creatine feeding in humans.
Blood and urine samples were obtained from four groups of healthy male subjects (A-D, total n = 22) before, during and after ingesting the following: group A, 5 g of creatine in solution; groups B and C, 5 g of creatine and 93 g of simple carbohydrate in solution: group D, a creatine- and carbohydrate-free solution. Subjects ingested the above preparations every 4 h for the remainder of the day and throughout the next day (total daily creatine dose = 20 g), and reported back to the laboratory on day 3 to undergo the same procedures as on day 1. Throughout this time, subjects weighed and recorded all dietary intake, and those in groups B and C ingested a prescribed isoenergetic high carbohydrate diet. Subjects in group C also performed 1 h of cycling exercise at 70% of their maximal oxygen consumption on the morning of each day. On both days 1 and 3, peak plasma creatine concentration, the area under the plasma creatine concentration/time curve and urinary creatine concentration were lower in groups B and C than in group A. Conversely, serum insulin concentration was higher in groups B and C than in A. No differences were evident when comparing groups B and C. These data suggest carbohydrate ingestion augmented creatine retention during creatine feeding and that creatine retention was not further increased when exercise was performed prior to ingestion.
Green
A L
AL
Department of Physiology and Pharmacology, University Medical School, Queen's Medical Centre, Nottingham, UK.
Simpson
E J
EJ
Littlewood
J J
JJ
Macdonald
I A
IA
Greenhaff
P L
PL
D000328:Adult; D003401:Creatine / Q000378:metabolism*; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D008297:Male
D004040:Dietary Carbohydrates; D007328:Insulin; D003401:Creatine