The overall aim of the study is to investigate the effects of an acute bout of physical activity on cognitive performance and long-term memory in elementary school children. Elaborating, the study seeks to investigate the effect of the intensity of the physical activity on cognitive performance and long-term memory in preadolescent children.

Based on a power analysis a total population of 100 children (four school classes) will be invited to participate in a 10-day protocol. The children will be randomly allocated, within their cluster (classes) and stratified for gender and soccer level, to one of 3 intervention groups. The groups consist of: A small-sides soccer game group (SSG), a walking soccer group (WSG) and a rest group watching soccer on TV (RES). At day 1 the children will complete a screening of their physical characteristics (height, weight, fat percentages, lean muscle mass and fitness status). On day 2 the children will complete a screening and a familiarization to the cognitive tasks used (cognitive performance and long-term memory) and the brain activity measuring devices (transportable EEG systems). On day 3 the children will complete the interventions, which first consist a long-term memory task, where the children will be asked to remember forty different pictures. Immediately after exposure to the forty pictures, the children will participate in 2 x 10 minutes of their respective interventions with 5 minutes break in between. During the break, the children will complete a short questionnaire to address their flow. Furthermore, during the intervention they will be equipped with heart rate monitors to quantify the physical demands of the intervention. Immediately after completing the 2 x 10 minutes interventions the children will be equipped with a transportable EEG system, and undergo a cognitive test (the Flanker task) to address their cognitive performance. The EEG recordings are used to measure the P3 amplitude and latency, biomarkers for cognitive performance. While equipping the children with the EEG system, the children will complete questionnaires about their participation. At day 10 the children will try to remember as many pictures of the forty pictures as possible to address the effect of the interventions on their long-term memory.

Inclusion Criteria:

• Informed consent from the childrens´ legal guardians.
• Physical, linguistic and mental competencies to complete the intervention and testing.

Exclusion Criteria:

• Use of prescription-only drugs that kan affect learning ability.
• Smoking.
• Neurological diseases inclusive damages to the spinal cord.
• Children who is not evaluated to being cable of completing the protocol among these psychological diseases or psychological unstable children.