32 ± 0.01 mg/100 mg wet tissue) (Figure 4). Additionally, a significant selleck chemicals llc inverse correlation (p < 0.05 - R= -0.67) between plasma lactate and muscle glycogen level (gastrocnemius) was found. Figure 4 Effects of creatine supplementation on gastrocnemius glycogen content. Pl - placebo group; CR - creatine group; * indicates p < 0.05 when compared to baseline. # indicates p < 0.05 when compared to Pl group Discussion The aim of
this study was to investigate the effects of CR supplementation on muscle glycogen Ruxolitinib content after high intensity intermittent exercise in rats. The major finding of this study is that a 5-day CR supplementation spared the gastrocnemius but not soleus glycogen content after a sub-maximal intermittent exercise in rats. The decreased blood lactate concentration in CR-supplemented rats supports the notion that the anaerobic glycolytic system has been less utilized as an energy source during the exercise protocol. The CR-induced glycogen sparing might partially explain the improved performance often observed in intermittent exercises as a consequence of
this supplement. The absence of significant change in soleus glycogen content is not surprising and reflects the rather low CR and glycogen content in type I vs. type II fibers [21], minimizing the impact of our intervention in the predominantly oxidative soleus muscle. The possible SB203580 order role of CR supplementation on muscle glycogen modulation has been previously pointed out [5]. The authors demonstrated that postexercise muscle glycogen storage can be augmented by CR and carbohydrate supplementation following exercise compared with carbohydrate ingestion alone. Thereafter, it has been shown that CR-supplemented subjects, during a phase of rehabilitation from immobilization-induced muscle atrophy, had larger muscle glycogen content when compared with non-supplemented subjects (650 versus 520 mmol/kg dry weight) [22]. Accordingly, an 18% increase in muscle glycogen content has been reported as a result of 5 days of concomitant CR and carbohydrate supplementation compared with placebo ingestion
[8]. It has been shown that performing a glycogen loading protocol (exhaustive exercise followed by a high carbohydrate diet for 3 days) after CR loading resulted in a 10% greater glycogen content when Reverse transcriptase compared to a glycogen loading before CR loading protocol [6]. In light of these findings, it has been speculated that CR supplementation could beneficially affect performance by modulating pre-exercise muscle glycogen content. Furthermore, it has been speculated that CR loading could also affect performance during exercise by increasing PCR content and consequently decreasing the reliance on glycolysis and muscle glycogen [23, 24]. However, no effect of a 5-day CR supplementation on muscle glycogen content has been reported in healthy volunteers either at rest or after continuous endurance exercise to exhaustion [11].