Neuroscience evidence suggests that physical exercise can influence brain function and structure, both immediately and in the long-term. The 'Fit to Study' project is a randomised controlled trial to test the effects on academic performance (as well as fitness, wellbeing and cognitive function) of a teacher-training intervention designed to optimise the content of PE for brain and cognitive function during secondary school (Year 8) Physical Education (PE) lessons. The project aims to rigorously test the impact of this intervention in 100 state-funded secondary schools.

Physical exercise has been shown to have positive effects on the brain and to improve cognitive performance, both immediately and in the long-term. This project is being conducted to understand better how the content of school PE, focusing on Year8 pupils during the academic year 2017/18, affects brain function and structure, and academic performance.

A programme of activities for PE lessons has been developed by Oxford Brookes University (in collaboration with Oxfordshire Sport and Physical Activity) to try to optimise the benefit of PE for brain function. Staff from Oxford Brookes University will train PE teachers to deliver this programme.

'Fit to Study' is aiming to recruit 100 state-funded secondary schools from within a radius of Oxford.

The National Foundation for Education Research will help with recruitment by sending materials to target schools, collating responses, collecting pupil information from schools that sign up, and passing information to the research teams and NatCen Social Research (who will be responsible for randomisation). Participating schools will be randomly assigned to either an Intervention Group (IG) and be asked to deliver the new PE programme, or to a Control Group (CG) and asked to continue with their normal PE lessons. Randomisation will be achieved using a random sequence generated using Stata12. Balance between treatment and control groups will be achieved across a range of covariates (i.e. to ensure not all girls schools are assigned to one condition).

For both Groups there will be a number of activities for schools to undertake, both at the start, during, and at the end of the study. The key tasks are listed, and then described, below:

• Online Cognitive Tests (pre- and post-study)
• Wellbeing Questionnaires (pre- and post-study)
• Physical Activity Assessments (before and during the study)
• PE Teacher Training for Intervention Schools
• Fitness (Beep) Tests (pre- and post-study)
• NatCen will undertake an Independent Evaluation of the 'Fit to Study' programme.

In all schools, the pupils in the target year group will undergo baseline assessments (in the final term of Year 7), which will comprise tests of physical fitness; cognitive assessments; and questionnaires (about physical activity, sleep patterns, mood, motivation and wellbeing). The tests of physical fitness will be administered during PE lessons and will involve measures of speed and endurance. The school PE teachers will be involved in the administration of these tests. The cognitive tests (which will include tests of memory, executive functions and attention using button responses), and some of the questionnaires, will be computer-based and may be administered over the web, at school or at home, using a well-established online testing package.

PE teachers in the intervention condition schools will be trained to administer our intervention. Our training package will comprise a set of focused lesson principles and techniques for their delivery.

To foster friendly competition between schools, the investigators may produce newsletters/bulletins containing school league tables indicating summary physical activity levels during PE and/or proportion of assessments completed, but these will never contain individual pupils' data.

The investigators will use activity monitors to compare physical activity during intervention and control PE lessons. At the end of the intervention period (which is intended to be an academic year), the Year 8 pupils in all schools will repeat the assessments.

In addition, the University of Oxford will be conducting a sub-study with a small number of pupils from a subset of schools. This is an optional part of the project and will be subject to separate written / informed consent from the pupils' parents/guardians. This will involve MRI brain scanning at the University of Oxford, as well as additional fitness and cognitive tests. Further detail will be made available to schools that are selected to take part in the Main Study (from May 2017).

Inclusion Criteria:

Inclusion is by school year group - typically aged 11-14:

• Year 7 pupils during the academic year 2016/17 (Age 11-12, KS3).
• Year 8 pupils during the academic year 2017/18 (Age 12-13, KS3).

Exclusion Criteria:

• Any pupils that are exempted from PE.
• Pupils that have 'opted out' of data sharing / storage for research purposes

On conclusion of the project, the Fischer Family Trust (see http://www.fft.org.uk/) will collate and upload anonymised data to the UK Data Archive (for the primary outcome measure). This archived data (for the primary outcome measure) will only be available in an anonymised form with restricted access for research purposes only.

Single blind (outcome assessor)