| Outcome Measures: |
Primary: Muscle protein synthesis rate, Measuring the rate of skeletal muscle growth in vivo by determining the rate of deuterium incorporation into muscle, 6 weeks|Muscle protein breakdown rate, Measuring the rate of breakdown of skeletal muscle in vivo using the rate of appearance of deuterium-labelled 3-methyl-histidine in blood after an initial oral bolus, 6 weeks | Secondary: Skeletal muscle mass, Determined from DXA scanning (measured in kg and percentage of total body weight) and novel techniques using rate of appearance of a creatine tracer in urine after an initial bolus, 12 weeks|Fat mass, Determined from DXA scanning (measured in kg and percentage of total body weight), 12 weeks|Total body weight, Measured in kg, 12 weeks|Whole body insulin sensitivity, Determined using the intravenous glucose tolerance test and measures of fasting insulin \& glucose, 12 weeks|Pancreatic beta cell function, Determined using the intravenous glucose tolerance test and measures of fasting insulin \& glucose, 12 weeks|Skeletal muscle strength, Determined from maximal voluntary contraction (MVC) of left knee extension, 12 weeks|Skeletal neuromuscular function, Assessed using measurement of force stability during electromyography, 12 weeks|Gross skeletal muscle function, Measured using a short battery of physical performance tests (SBPPT) to give an overall score of skeletal gross skeletal muscle function (scored out of 12), 12 weeks|Right vastus lateralis muscle thickness, Determined from muscle ultrasonography, 12 weeks|Right vastus lateralis muscle cross sectional area (CSA), Determined from muscle ultrasonography, 12 weeks|Right vastus lateralis muscle fibre pennation angle, Determined from muscle ultrasonography, 12 weeks
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