The experimental group will participate in a 24 week multi-component programme that includes four strands:

• A physical literacy programme focusing on core elements of strength, agility, speed, balance and flexibility. Delivered by external facilitators for one hour per week over 16 weeks of the programme (2 x8week blocks).
• 'Golden Mile' - pupils and teachers participate 15min walk/run a min of 2 times per week
• After schools club (not compulsory) featuring mind-set component delivered by external facilitators
• Healthy kidz app with reward system

The control group will continue doing physical activity including physical education as is normal for their school

A 24 week physical activity intervention to promote fitness and wellbeing in primary schools

Change from baseline in fitness as assessed as speed and agility (20 second shuttle run), core strength (timed lying leg raise) and flexibility and balance (single standing leg raise).

KIDSCREEN is a validated self-report measure of children's subjective health and well-being. Kidscreen-10 is a 10 item instrument which gives a global health related quality of life score. Scores range from 10 to 50, with higher values indicate a higher health related quality of life.

The Physical Activity Questionnaire for Older Children (PAQ-C) is a validated self-report questionnaire designed to assess moderate to vigorous physical activity in children over a 7 day recall. Items are scored using a 5-point scale and a mean of all 9 items is used to create an overall PAQ-C activity summary score, with higher scores indicating higher levels of physical activity.

Validated scale consisting of seven negatively worded items from the PACES study. Seven items are rated on a 5-point Likert-type type scale ranging from 1 (disagree a lot) to 5 (agree a lot). Items are summed to generate the S-PACES score, and higher scores reflect greater levels of enjoyment.