Creatine supplementation strategies aimed at acutely increasing and maintaining skeletal muscle total creatine content in healthy, young volunteers

Pittas, George; Miller, Jan; Laithwaite, David; Greenhaff, Paul

Abstract

Objectives: Insight regarding dietary creatine (Cr) supple-mentation strategies to acutely increase and maintain muscle total creatine (TCr) content is missing. Methods: Healthy, young, men ingested 4 × 5 g Cr/day (d) for 5d, followed by 5 g/d for 28 d (Cr group, n=8). To achieve insulin mediated muscle Cr transport, another group (n=16) ingested 4 × 5 g Cr plus 95 g dextrose/d for 5d (CrCHO), and thereafter two subgroups ingested 5 g of Cr (CrCHO1, n=8) or 5 g Cr plus 95 g dextrose/d for 28 d (CrCHO2, n=8). A fourth group ingested 4 × 5g of Cr plus 14 g protein, 7 g phenylala-nine, 7 g leucine and 57 g dextrose/d for 5 d, and once/ d thereafter for 28 d (CrPAC, n=8). Muscle biopsies were obtained at 0, and after 5 and 33 d. Results: After 5 d, muscle TCr increased in Cr (p<0.001), CrCHO (p<0.001), and CrPAC (p<0.05) groups, and was numerically greatest in CrCHO; achieving a content reported to be an average maximum (150 mmol/kg). After 33 d, TCr also increased to ~150 mmol/kg in the Cr group (p<0.05), remained unchanged from 5 d in CrCHO2, and tended to decline in CrCHO1. Muscle TCr remained unchanged from 5 d in CrPAC after 33 d, being less than the Cr group (p<0.05). Muscle Cr transporter mRNA expression changed modestly, but the increase in muscle TCr after 5 d was inversely associated with fold-change in mRNA expression (r=0.502, p<0.05). Conclusions: A maximum increase in muscle TCr is achieved after 5 d Cr ingestion alongside 95 g dextrose, and continued consumption of Cr with dextrose will maintain this maximum. Ingestion of Cr alone will achieve a high muscle TCr content too, but takes longer.

Citation

Pittas, G., Miller, J., Laithwaite, D., & Greenhaff, P. (2024). Creatine supplementation strategies aimed at acutely increasing and maintaining skeletal muscle total creatine content in healthy, young volunteers. Translational Exercise Biomedicine, https://doi.org/10.1515/teb-2024-0032

• Journal Article Type: Article
• Acceptance Date: Oct 24, 2024
• Online Publication Date: Dec 6, 2024
• Publication Date: Dec 6, 2024
• Deposit Date: Dec 9, 2024
• Publicly Available Date: Dec 9, 2024
• Journal: Translational Exercise Biomedicine
• Electronic ISSN: 942-6812
• Publisher: De Gruyter
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1515/teb-2024-0032
• Keywords: exercise nutrition; dietary supplements; insulin; dextrose
• Public URL: https://nottingham-repository.worktribe.com/output/42832145
• Publisher URL: https://www.degruyter.com/document/doi/10.1515/teb-2024-0032/html