The 28th National Playday is being held today across the UK.

Every year support for the initiative continues to grow across Scotland as children, young people and communities enjoy playing outside to celebrate the importance of play.

Set up in London to raise the profile of play and alert people to the potential loss of children's play services, Playday is co-ordinated by a network of people who are passionate about play in Play Scotland; Play Wales; Play England and PlayBoard Northern Ireland.

Every child has a right to play and needs to play freely in order to grow into a healthy, happy, creative and confident adult.

We all know this because, when we think back to our own play memories, we remember the thrills and spills that left many of us with scars on our knees to this day, the loneliness of being left out, the joy of making new friends and the agony of not being discovered at hide and seek. Hardly a week goes by without a study suggesting that our children don't play out nearly often enough.

One survey reported this month that half of Scottish children under the age of 10 have a mobile phone and will be spending an additional 60 hours playing on them during the summer holidays. Almost one-fifth of the children surveyed said they would prefer to engage with their friends via apps, texts or social media rather than with people face to face, and many give up sleep time for screen time.

Earlier this year, Scotland scored bottom of the class in indicators for children's overall exercise and performed badly for the amount of time they spent in front of television and computer screens.

However, findings of the Global Matrix of children's physical activity study, which involved researchers at Strathclyde University, were very positive about the policy and provision levels in Scotland. But we need innovative ways and showcase events such as Playday to encourage participation.

There are many barriers to children playing outside, both real and imagined, and as parents we need to take positive action to plan for play. The freedom and opportunities to play that we took for granted are not readily available to our young people and need to be thought about carefully by parents and planners alike.

We know from UK Playday surveys that more than 80% of children want to spend more time playing outdoors. One-third say they never climb trees, or build dens or have time to play. Fears about traffic and strangers also combine to limit play opportunities.

This is where National Playday can make a difference. Across the UK, National Playday calls on local authorities, community groups, parents and families to make time to get out and play with children. Remember the fun, reflect on the benefits of play and help create the opportunities for puddling, den building, climbing trees, making and baking mud pies.

The Move More study, partly funded by the World Cancer Research Fund, has highlighted the need for children to be given more opportunities to play outdoors with friends. The former Chief Medical Officer in Scotland, Sir Harry Burns, is a champion of children's play. He says: "investing in children's play is one of the best things we can do to improve children's health and wellbeing in Scotland."

To support Playday, the Children's Play Policy Forum is releasing The Play Return, a review of the wider impact of play initiatives by Tim Gill. The report presents evidence to build the case for improving the play opportunities of children and young people. Its focus is on children of school age, and on free play that takes place outdoors. It looks at quantitative evidence of the wider outcomes and impact of play interventions and initiatives.

The report looks at four types of intervention that each involve setting aside time and space for children to play: improving opportunities for free play in school break times, unstaffed public play facilities, supervised out-of-school play provision and street play initiatives.