Simultaneous multi-task training has been used many times in different age groups to improve cognitive as well as motor performance. In adolescents, there are already results that this training can improve academic performance. The scoping review by Wollesen et al. "Effects of cognitive-motor dual task training on cognitive and physical performance in healthy children and adolescents: A scoping review" aimed to summarise the effects of training with simultaneous multi-tasking interventions in the domains of cognition, motor skills and dual-tasking performance.
The full length paper can be found here