Age Related Sarcopenia

Life expectancy has been increasing for the last 150 years, but the maintenance of health has not kept pace with increased lifespan, and on average, UK adults spend the last decade of life in poor-health, with major consequences for society and the individual. Persistent physical inactivity is thought to be a key contributing factor to the risk of poor health and functional decline occurring in middle-aged and older adults. It is therefore concerning that most middle-aged adults spend \>8hrs/day being sedentary, with average step count of 3000-4000 steps/day. To be able to holistically assess the effectiveness of future strategies to address age-related decline in health, and devise public health messages to help individuals reach older age in better health, it is essential that the complex physiological effects that activity and inactivity have across biological systems are characterised. The goal of this intervention study is to compare the impact of physical activity and inactivity on body functioning. Twenty moderately active participants will decrease their physical activity for three months to match the average amount carried out by middle-aged people in the UK. They will then undertake 3-months of reconditioning training to restore their fitness. In addition, twenty sedentary participants will increase their physical activity to UK recommended levels for six months. Before and at points during the intervention period, participants will be asked to make some measurements at home and attend the University of Nottingham to have multiple assessments made. These include; * fitness, muscle strength and function tests, * completion of questionnaires and computer-based brain puzzles * having muscle and fat tissue biopsies and blood samples taken. * The study also involves having MRI scans. This 5-year study will commence in January 2024, with participant recruitment starting in March 2024 and finishing in May 2027.

As people age, muscle mass and function is lost and exercise training is an important way to reduce the effects of this and remain independent. However, not everyone can perform this exercise and the muscle responses to exercise are often reduced in older people. So far there has been no drug found to specifically treat or reduce this problem. Muscle size depends on the balance of muscle protein breakdown and synthesis (building). This balance is regulated by multiple signals within the body, but a particular molecule - the mechanistic target of rapamycin (mTOR), is known to play an important role. For protein synthesis to build up the muscles, this pathway is needed to start the process when triggered by eating protein or exercise. Although this would suggest that mTOR activity is good, excessive levels of this signalling seem to have negative impacts on muscle maintenance with age. In animal studies, blocking mTOR signalling has stopped the development of a number of age-related diseases and increased health-span. Drugs that block this pathway (e.g. Rapamune) reduce the stimulation of muscle protein synthesis, possibly through changing the immune system, but conversely have also been shown to increase muscle size and reduce markers of nerve supply loss. This means that drugs which block the mTOR pathway could, in older people, help to reduce the negative impacts of excessive mTOR signalling on muscle size and function. The investigators aim to recruit 16 healthy male volunteers over 50 years old to investigate how the drug Rapamune (which blocks the mTOR pathway) affects aged human muscle both on its own and when combined with resistance exercise training.

This is a randomized interventional clinical trial, whereby 100 participants will be randomized to either follow the SAFE exercise program (experimental group) or not (control group). At the end of the intervention, the experimental group will be encouraged to continue doing the exercises, and the control group will have the opportunity to participate in the SAFE exercises. 12 weeks post-intervention, the investigators will follow up with participants by telephone to follow up whether they are still following the SAFE program or not.