Mobile Subthreshold Exercise Program for Concussion

• Change in Pediatric Quality of Life Inventory (PedsQL)[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report questionnaire regarding Health-related quality of life
• Change in Fear of pain questionnaire (FOPQ)-P/C, adapted for concussion[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report questionnaire completed by parent and child regarding their fear of concussive symptoms and avoidance of activities that might produce concussive symptoms
• Change in Patient Health Questionnaire 9 (PHQ-9)[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report questionnaire of depression symptoms
• Change in PROMIS Positive affect[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report questionnaire of positive mood levels
• Change in moderate to vigorous physical activity (MVPA)[ Time Frame: Change from baseline to 6 weeks ]
  Average minutes per day of MVPA, measured using hip-mounted accelerometry
• Change in Adolescent Sleep Wake Scale (ASWS)[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report 10-item questionnaire regarding difficulty falling asleep, night wakenings and other sleep issues
• Change in Sport participation questionnaire[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report questionnaire regarding sporting and recreational activities that a youth participated in that week
• Change in Physical activity parenting[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report questionnaire (completed by parents) regarding their approach to physical activity with their child.
• Change in Adult responses to child's symptoms (ARCS), adapted for concussion[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report questionnaire regarding parenting responses to child's concussive symptoms
• Change in Generalized anxiety disorder--7 item (GAD7)[ Time Frame: Trajectory over 6 weeks (baseline, 3 weeks, 6 weeks) ]
  Self-report questionnaire regarding anxiety symptoms (7-item)

Non-randomized pilot intervention using mobile-administered sub-threshold exercise to treat youth with prolonged symptoms of concussion.

• Behavioral: M-STEP
  Youth will be assessed using actigraphy at baseline, and will then be asked to exercise for 1) a duration of 10 minutes > MVPA at baseline with 2) HR>120 while being monitored by a Fitbit. Youth will be asked to exercise daily, and intensity and duration will be increased every few days for a goal of 60 minutes per day at a HR>140 (low end of MVPA). The intervention will be 6 weeks in duration.

• Experimental: M-STEP
  Mobile exercise intervention