The goal of this pilot clinical trial is to assess the feasibility of administering a paced breathing exercise intervention program to children and adolescents in the sub-acute period after concussion, and to document the autonomic function, and symptom severity (post-concussion symptoms, anxiety, sleep) before and after administration of the intervention. Participants will: will be instructed to perform a daily 10-minutes daily paced breathing home-exercise program and to document the daily exercises performed within a performance log, or receive usual care from a concussion follow-up program. A weekly phone meeting will be performed with the participants, to review exercise, providing, specific instructions, and making any necessary adjustments. All participants (intervention and control group) will undergo a second assessment after four weeks following completion of the intervention program. During the second assessment information regarding the intervention feasibility, time to return to school, return to sport, and clear from medication will be collected as well.