Creatine (methyl-d3) dilution (D3-creatine) is a novel technique for the estimation of muscle mass. The method uses a dose of deuterium-labelled creatine to determine total skeletal muscle mass via estimation of total body creatine pool size.The aim of this study is to compare estimates of total body skeletal muscle mass by D3-creatine dilution method and whole body Magnetic Resonance Imaging (MRI) in an athletic population.

Inclusion Criteria:

• Trained and competing elite canoe athletes will be recruited, who represent Great Britain Canoeing

Exclusion Criteria:

• Pregnant and lactating women
• Intolerance or hypersensitivity to Creatine supplementation
• Athletes with disabilities which affect their total body muscle mass
• If creatine was taken in a supplemented form, rather than dietary intake, more regularly than once a week within 6-weeks of assessment commencing
• Contraindication to an MRI scan