Study to look at effect of exercise and nutrition on muscle in old age

Nov 29 2007

Experts at The University of Nottingham are looking to recruit men of two specific age groups to help understand the effect of exercise and nutrition on muscle in old age.

The team from the School of Graduate Entry Medicine and Health at Derby City General Hospital, expect this information will help the elderly avoid falls and fractures by discovering the amount of exercise and the kind of nutrition needed to maintain and rebuild muscles.

Muscle makes up about half the body weight of a healthy person. It is vital to maintain health and physical strength for functional independence. However, as we age we lose muscle. These changes begin at around 45 to 50 years of age. This ultimately leads to decreased strength, increased fatigue, a decline in joint stability and thus to falls and broken bones.

Leading this research is Michael Rennie, Professor of Clinical Physiology, and an expert on muscle growth and wasting in health and disease. He said: “If we can preserve muscle tissue and maintain health and independence as we get older that in turn would reduce healthcare costs associated with age related muscle wasting. We already know that it is harder for older people to maintain their muscles and we know that exercise can build muscle. What we do not yet know is how much or how little exercise is needed to do this or how best to feed people to maximise the benefit.”

Muscle is made of protein and amino acids (which are the building blocks of protein) are very important in stimulating the synthesis of muscle. As we get older our body’s ability to respond fully to a protein meal is greatly diminished. However, previous research by the Derby group and others has shown that resistance exercise such as lifting weights, can greatly increase muscle protein synthesis, muscle mass and strength. By combining the right amount of exercise and optimised nutrition the team hope to maximise the growth of muscle and therefore delay the muscle wasting that inevitably accompanies even healthy ageing.

They now wish to recruit healthy male volunteers to carry out these studies after obtaining funding from Unilever plc. The researchers are looking for non-smoking volunteers aged between 18 and 30 or 65 and 75. Initially, the volunteers will undergo health screening and a body scan to measure their muscle composition and muscle strength. On two separate occasions, under the supervision of a doctor and scientists, they will take part in exercise of varying intensity and duration. During these visits, a tagged amino acid will be infused and blood samples and muscle biopsies will be taken, under local anaesthesia, from thigh muscle so the researchers can measure the body’s ability to make muscle in response to exercise and feeding. The research group has over 20 years experience of carrying out these types of metabolic studies. Volunteers will also receive an honorarium to cover their expense.

Dr Vinod Kumar, who is currently recruiting volunteers, said: “I am really excited to be involved in this project because it is inevitable that we will all grow old. So, if we can determine how to maintain muscle mass as we age it will greatly benefit us all.”

The study has just started and they hope to finish by the middle of 2009. The team needs to recruit 78 volunteers over the next 18 months and results should begin to come through by the middle of 2008.