Inga prestationshöjande effekter av maltodextrin före styrketräning

[King Grub]

Most of the research investigating the ergogenic enhancing mechanisms of carbohydrate have been conducted using aerobic based exercise. Therefore, the purpose of this study was to investigate the effects of pre-exercise maltodextrin ingestion on resistance exercise performance, serum insulin, epinephrine, glucose, and muscle glycogen concentrations. In a double blind, cross over, repeated measures design, participants completed four sets to failure at 70% of 1-RM with 45s rest on the angled leg press with or without pre-exercise maltodextrin (2g/kg) after a 3hr fast. Serum glucose, epinephrine, and insulin were assessed at baseline, 30 min post-ingestion, immediately after, and 1hr post-exercise with or without carbohydrate supplementation. Muscle glycogen was assessed from biopsy specimens sampled from the vastus lateralis before supplementation, immediately after exercise, and 1hr post exercise under both conditions. There was no main effect of supplement on resistance exercise performance (p = 0.18). Muscle glycogen concentration decreased across time for both groups (p < 0.001). There was an interaction in serum glucose decreasing more during exercise in the carbohydrate condition (p = 0.026). An interaction occurred showing insulin decreased during exercise in the carbohydrate condition (p = 0.003). Also, there was a main effect of insulin being elevated with carbohydrate consumption (p = 0.027). Epinephrine was decreased across all time points after carbohydrate ingestion (p = 0.023). Carbohydrate supplementation before resistance exercise did not improve leg press performance to fatigue despite increased metabolic substrate availability. These results indicate that pre-exercise dietary carbohydrate will be utilized preferentially during exercise due to decreased epinephrine, decreased serum glucose, and increased insulin concentrations. However, the increases in glycolytic substrate availability will not increase exercise performance or glycogen content following 1hr of recovery.

Journal of Sports Science and Medicine (2020) 19, 282 - 288. Acute Maltodextrin Supplementation During Resistance Exercise.

[ChuckTesta]

Vill man prestera bra så känns det som att man måste förbereda det dagen innan (senast). Vad man gör precis innan man ska lyfta känns som att det spelar mer eller mindre ingen roll. Ibland är jag starkare när jag är trött och fastande än om man vaknar tidigare och hinner äta något osv.

[Ola Wallengren]

Tidigare forkning visar inte heller att kolhydrater vid styrketräning ahr någon övertygande effekt, har jag för mig. Däremot tränade de ju bara i cirka 6 minuter i denna studie. Attt glykogen och blodsocker skulle begränsa under denna korta tid är inte så sannolikt.

Anekdotiskt skulle jag säga att kolhydrater kanske gör nytta vid hårda styrketräningspass på > ca 75 minuter (kanske ännu längre).

[exevision]

Hade de bara "fastat" i tre timmar före de fick malto?
Vad hade de ätit före dessa tre timmar?