The first goal of this study is the follow young and older people over a period of 8 weeks to define the processes responsible for loss of muscle length and width in age-related muscle wasting (sarcopenia) and allow us to look at age-related differences in tendon. Secondly, we will assess two different exercise interventions for reversing human sarcopenia; one which involves shortening of the muscle and the other which involves lengthening, whilst also studying why these exercises work the way they do. This project will have significant implications for our understanding of the control of skeletal muscle and tendon size in humans, particularly in relation to sarcopenia and the surrounding health issues.

Inclusion Criteria:

• Healthy male volunteers
• Body mass index 18-30 kg/m2
• Aged 18-35 and 65-75 years

Exclusion Criteria:

• Participation in a formal exercise regime,
• A BMI < 18 or > 30 kg/m2,
• Active cardiovascular disease,
• Taking beta-adrenergic blocking agents, statins or non-steroidal anti-inflammatory drugs,
• Cerebrovascular disease,
• Respiratory disease,
• Metabolic disease,
• Active inflammatory bowel or renal disease,
• Malignancy,
• Recent steroid treatment (within 6 months) or hormone replacement therapy,
• Clotting dysfunction,
• Musculoskeletal or neurological disorders,
• Family history of early (<55y) death from cardiovascular disease