Concerns over many children's low levels of physical activity are now widespread. Some observers have described the youth of today as "couch kids".
We only have to observe the habits of Harry Enfield's infamous teenage character Kevin to appreciate some of the problems. Kevin is addicted to watching TV, computer games, labour-saving gadgets and junk food. He is taxied everywhere by his devoted and over-protective parents and will go to great lengths to escape chores such as tidying his room.
While much of this behaviour may be seen as that of a typical teenager from any generation, there is no doubt that the pressures on young people today to be sedentary, are enormous. And the younger the child, the greater the pressures.
Changing lifestyles - more use of technology such as cars, TV, computers and labour-saving devices - media messages and attractive alternative leisure pursuits affect us all and reduce opportunities for daily physical activity. Children face additional constraints. School, for example, is essentially a "sitting down" experience in which the "well behaved" child is typically a sedentary child.
Beyond school, parental concerns about safety mean children have less freedom to be independently active than in previous generations. There has been a marked reduction in walking and cycling to school in the past 20 years, and children spend less time outdoors and more time watching TV or playing computer games in the safety of their own homes.
Aside from parental restrictions, adults generally curb children's activity. For example, no ball games policies on estates, in parks and in some schools, and adults' general intolerance of children playing out, are commonplace.
Such actions and fears, it has been suggested, may be keeping many children under something akin to house arrest, and denying them their right to play as enshrined in the Human Rights Act 1998 and the United Nations'
Convention on the Rights of the Child. Worryingly, they could also quash children's natural instincts for activity and impair physical, social and cognitive development. Although parents' fears and perceptions are perhaps understandable, a challenge must be to tackle the causes of these, as well as to encourage society generally to be more child-friendly and tolerant.
While this issue is clearly complex and beyond the responsibility and control of schools (environmental and policy change is required), there are nonetheless some simple measures and actions schools can take which would help.
For instance, walking or cycling to school can be made safer and easier for children by imposing speed restrictions or pedestrian-only zones around schools, providing pedestrian or cycle training, secure cycle storage, and by promoting "walking bus" schemes or walk to school weeks. Play within the confines of the school grounds can be encouraged by providing play and sports equipment and playground markings, or training break and lunchtime supervisors or older pupils to organise games.
Two exciting initiatives which schools might take advantage of, and which support many of the above ideas, include Zoneparks, a playground improvement project developed by the Youth Sport Trust and supported by the Department for Education and Skills and Nike, and Safe Routes to Schools, developed by Sustrans, the sustainable transport charity.
Community initiatives developed by the Children's Play Council, such as Home Zones and the Neighbourhood Play Toolkit, may also offer some ideas.
The above are just a few of the many initiatives promoting children's physical activity.
Progress is being made but there is still much to do. If we are to truly make a difference to children's activity levels, then attitudes towards young people need to change, to secure them the freedom and legal rights to play and to lead a healthy, active childhood.
Lorraine Cale is director of PE teacher education at Loughborough university. Details of Safe Routes to Schools can be found at www.sustrans.org.uk orvia emailing email@example.comFor details of Children's Play Council initiatives see www.ncb.org.ukZoneparks: www.youthsporttrust.org