Opportunities for physical activity every school day, more time for "higher quality" PE, and "sustained" competitive sport in schools.
These three demands form the backbone of the Youth Sport Trust's General Election manifesto, which was published last week.
Launching the manifesto, Baroness Sue Campbell, chair of the body, described the current physical inactivity levels of young people as "bleak and worrying". She pointed to figures showing that one in three children leave primary school obese or overweight, and less than one in five meet the minimum recommended guidelines for physical activity.
She said it was crucial that the health, education and sports sectors worked together to tackle the issue.
The Trust described recent initiatives, such as the Sports Premium for primary schools and the national School Games, as "positive interventions".
However, it also points to its PE and School Sport survey last year, involving 554 secondary and 1,392 primary schools, which found that pupils across all key stages were being offered less than two hours of PE a week.
At key stage 2, pupils spend 114 minutes on PE a week, down from 127 minutes in a similar survey in 2009/10.
At key stage 1, pupils spend 102 minutes on PE a week, down from 126 minutes in a similar survey in 2009/10.
The survey also revealed that links to community sports clubs had fallen from around eight per primary school in 2009/10 to an average of four now.
Specifically, the Trust's 2015 manifesto calls for every child to receive five hours of "high-quality PE, sport and broader physical activity at school every week". This should include at least two hours of high quality PE per week, it states.
Better initial training in PE for teachers, especially at primary level, is also called for.
The manifesto adds: "At secondary level, every school should have a director of sport who is responsible for implementing an inclusive and vibrant PE and school sport programme. The director of sport should also organise and promote participation in sport outside of curriculum time, and build links with local community sports organisations."
For the health sector, the manifesto says that a key aim should be supporting all schools to have programmes to "engage the least active". With support from government, health services must also "advocate the role of schools in supporting the physical health and emotional wellbeing of pupils", it adds.
The sports sector, meanwhile, should offer all young people the opportunity to "participate in competitive sport as a participant, volunteer or leader".
Baroness Campbell said: "We have set out where we believe any future government should focus its efforts if we are to stand any real chance of reversing the worrying trends that are leading to increasing sedentary lifestyles among young people."
You can download the manifesto at http://bit.ly/1ui4QFG