Every day, millions of us pull on our trainers and hit the streets in an attempt to get fitter while enjoying the great outdoors. But is our love affair with running storing up health problems for us in the future?
That's the question a new international study led by researchers at The University of Nottingham, as part of the Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, is aiming to answer - with a little help from several thousand participants in the increasingly popular weekly parkrun events.
Over the next 15 years, the Health of Adults' Longitudinal Observational (HALO) study, with the approval of the parkrun Research Board, will follow the fortunes of the volunteer participants to assess whether recreational running puts people at greater risk of developing osteoarthritis (OA) of the knee in later life.
Leading the study - which is launching during National Arthritis Week - is Dr Kim Edwards, Associate Professor in the University's School of Medicine. She said: "One difficulty with research about physical activity and health is the lack of detailed data, especially running data, on large samples over many years.
"For example, many individuals believe that running will have a detrimental effect on their knees, yet the balance of previous research suggests that this is not necessarily the case. However, these were small investigations and a large study is needed. Additionally, in an ageing society, with increasing obesity and sedentary lifestyles, it is clear that a greater understanding in this area would be beneficial to the overall population."
Recreational running has become one of our most popular pastimes and the parkrun organisation, which provides free weekly 5km running events around the world, has 800,000 members in the UK alone.
The HALO study is aiming to recruit at least one per cent of all parkrun participants across the 350 locations in the UK (8,000) and a further 1,500 parkrunners in Australia.
Not all parkrun participants run - some walk the 5k route while others sign-up and volunteer at events. This will allow the study to recruit across the spectrum of physical activity. Additionally the research team will also be aiming to recruit 700 'sedentary' volunteers.
University of Nottingham PhD student Richard Leech, who works at the Centre, is currently working with the University of Sydney and is recruiting Australian volunteers for the study.
He said: "It is really important that physical activity is encouraged within our society. Our research seeks to identify the short and long-term outcomes associated with recreational running. In doing so we wish to identify the benefits, particularly in relation to musculoskeletal health, so that people of all ages can participate safely."
The participants will be asked to complete a questionnaire about their age, height, physical activity, their running habits, hobbies and pets, general health and injuries, osteoarthritis, knee problems, pain and stiffness.
With agreement, the researchers will then follow up with participants at 12 months and every two to five years subsequently until the end of the study in 2030.
All participants will also be offered the opportunity to get further involved in the research by volunteering for a number of sub-groups within the study. One subgroup will be invited to use a series of physical tasks to assess the potential link between knee function and potential risk factors for knee OA for recreational runners compared to non-runners and high-performance runners. Another sub group of 600 willing participants will be asked to give blood samples that will allow researchers to extract their DNA and assess whether they are genetically more at risk from injury and disease.
It is hoped that in addition to providing evidence on the link between running and knee OA, the study will give us a much clearer picture of how other lifestyle factors such as diet and general physical activity impact on our risk of developing injuries and diseases.
Centre Director Professor Mark Batt, of Nottingham University Hospitals NHS Trust, said: "Generally, sport and exercise are very good for us, and it is vital that we continue to promote this important public health message. We want to understand the risk factors and, importantly, the protecting factors there may be in being active and exercising regularly."
Dr Stephen Simpson, director of research and programmes at Arthritis Research UK, said: "Over eight million people are living with the pain of osteoarthritis in the UK. We understand it can be difficult to find the right balance and intensity when taking on an aerobic exercise such as running, especially for people with joint problems. This study is an exciting example of the research we are currently funding so we can understand how we can exercise safely without risk of injury or joint problems which could lead to osteoarthritis later in life."
Anyone who is interested in taking part can contact Dr Kim Edwards in the University's School of Medicine by email at Kimberley.firstname.lastname@example.org
The study is being conducted through the Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, which is led by Nottingham University Hospitals NHS Trust and is a consortium of seven universities, including the Nottingham, Oxford, Southampton, Bath, Loughborough, Leeds and University College London.