UD2 ??
sadze ze
MCT moze posrednio (!) oszczedzac glikogen w dluzszej perspektywie
jednak dodanie do posilku przed trneingiem MCT
nie zmienialo utylizacji glikogenu przez miesnie
Preexercise medium-chain triglyceride ingestion does not alter muscle glycogen use during exercise
Jeffrey F. Horowitz,
Ricardo Mora-Rodriguez,
Lauri O. Byerley, and
Edward F. Coyle
+ Author Affiliations
1 Department of Kinesiology and Health Education, The Human Performance Laboratory, The University of Texas at Austin, Austin, Texas 78712
Submitted 25 May 1999.
accepted in final form 23 September 1999.
Abstract
This investigation determined
whether ingestion of a tolerable amount of medium-chain triglycerides (MCT; ∼25 g) reduces the rate of muscle glycogen use during high-intensity exercise. On two occasions, seven well-trained men cycled for 30 min at 84% maximal O2 uptake. Exactly 1 h before exercise, they ingested either 1) carbohydrate (CHO; 0.72 g sucrose/kg) or 2) MCT+CHO [0.36 g tricaprin (C10:0)/kg plus 0.72 g sucrose/kg]. The change in glycogen concentration was measured in biopsies taken from the vastus lateralis before and after exercise. Additionally, glycogen oxidation was calculated as the difference between total carbohydrate oxidation and the rate of glucose disappearance from plasma (Rd glucose), as measured by stable isotope dilution techniques. The change in muscle glycogen concentration was not different during MCT+CHO and CHO (42.0 ± 4.6 vs. 38.8 ± 4.0 μmol glucosyl units/g wet wt). Furthermore, calculated glycogen oxidation was also similar (331 ± 18 vs. 329 ± 15 μmol ⋅ kg− 1 ⋅ min− 1). The coingestion of MCT+CHO did increase (P < 0.05) Rd glucose at rest compared with CHO (26.9 ± 1.5 vs. 20.7 ± 0.7 μmol ⋅kg− 1 ⋅ min− 1), yet during exercise Rd glucose was not different during the two trials. Therefore,
the addition of a small amount of MCT to a preexercise CHO meal did not reduce muscle glycogen oxidation during high-intensity exercise, but it did increase glucose uptake at rest.
szosiu
Krzysztof Piekarz
Biniu
