Teens, Screens, and Active Routines: The Formula for Exam Success

The neuroscience behind why the type of break your teenager takes during finals matters more than you think

By Jess Wight | June 24, 2026

“Exercise is one of the most effective ways to improve brain health.”

Neuroscientist Jennifer Heisz at McMaster University in Hamilton, Canada, discussing the role of exercise in supporting learning and brain health.

We have been conditioned to think that any downtime is good downtime. When a teenager is drowning in homework, exam stress, and intense pressure to succeed, our instinct as adults is often to tell them to ‘take a break’. But according to a study emerging from Yonsei University just last week, the type of break matters greatly. Researchers tracked how adolescents cope with academic stress and found a striking contrast: while physical activity (PA) appeared to protect against depression, another common escape—cellphone scrolling—actually makes the mental burden worse. This has exposed a significant difference between active and passive leisure: one builds psychological resilience, the other can erode it.

The mental health benefits of exercise are backed by large-scale evidence. A 2026 publication in BMC Psychology of over 5,000 students found that regular PA improves emotional regulation and flexibility. Similarly, a systematic review of nearly 8,000 adolescents across twenty-four studies confirmed that exercise reduces symptoms of depression and anxiety.

Beyond mental health, exercise also supports cognition and academic performance. Research shows improvements in processing speed, attention, memory, cognitive flexibility, and language skills. Researchers using longitudinal data from the “Children of the 90’s” study in the UK even found that higher vigorous physical activity in adolescence predicted better grades in English, maths, and science.

Extensive rodent research reveals that PA actively triggers profound neuroplastic changes in the brain, improving key traits like processing speed, attention, working memory and cognitive flexibility. A systematic review in 2020 covered fifteen studies examining the effects of PA - either treadmills or voluntary running wheels - on various measures of cognition in rodents. Their results were striking, four primary biological mechanisms resulting from increased exercise:

1)      Chemical changes: significantly boosts three key growth factors in the brain which support cell maintenance and growth

2)      Stronger connections: significantly increased synaptogenesis, the process of creating more pathways in the brain

3)      Enhanced blood supply: stimulates angiogenesis (the creation of new blood vessels) in the brain providing more oxygen and nutrients

4)      New cell growth: triggers neurogenesis, the process of growing new brain cells

Due to a large genetic overlap of 85% and almost identical brain structure to rodents, these results are mirrored in humans: recent literature reviews and meta-analyses consistently show that physically active adolescents demonstrate improvements in a range of cognitive domains, with improvements translating directly to the classroom too: regular PA and sports team participation in schools US were associated with a higher GPA in a study of almost 5000 teenagers.  

With exercise clearly being so beneficial for teens, it is easy to see why scientists are pushing for more PA interventions in schools. However, when the COVID-19 pandemic hit, gym closures and cancelled sports caused PA in adolescents to plummet. In Canada, it was reported only 37% of youth met activity guidelines in 2020.

Yet during this same crisis, a fascinating trend emerged: social media became the primary source of fitness inspiration. The rise of ‘fitness influencers’ actually predicted higher motivation and workout behavior among isolated teens as reported by a new study.

Researchers therefore advocate for the use of social media to promote wellbeing rather than abstaining from it. However, they remain in the minority with regards to published positive influences of cellphone use in adolescents.

This highlights a major limitation of the current cellphone research landscape. Problematic usage studies – like the 2021 meta-analysis covering 147 000 individuals – often dominate the headlines, concluding that phone use hurts learning. However, these studies focus exclusively on individuals labeled as “addicted”, a classification that remains subjective due to the lack of a standardized diagnostic tool. Consequently, these findings fail to represent adolescent cellphone usage as a whole, inadvertently reinforcing the prevailing negative stereotypes surrounding teens and technology.

Many studies have reported association between cellphone usage and poor mental health and stress, but not explored the direction of this relationship. A recent study of university students found highly stressed individuals were more dependent on their phones, with a systematic review substantiating these findings, also reporting cellphone use to be linked to mental health problems such as depression and anxiety.

Comparatively, another study in 2020 identified students most frequently used coping strategies for academic stress, with cellphone use being the most popular as a means to access their favourite leisure activities such as music, entertainment, and communication. The authors stated that “our results show that university students are attempting to use cellphones to combat stress” rather than suggesting an increase in academic stress is connected to greater cellphone use: an important distinction to consider in future research.

Prevailing narrative assumes phone use causes poor mental health. In reality, the reverse might be true: teens struggling with academic stress, depression, and anxiety may simply be turning to their phones as a coping mechanism. In a study looking at how students manage stress, more than half agreed they use their phone “as a way of escaping from problems or relieving a bad mood”.

Furthermore, when used correctly, electronic devices actively aid learning and development. The Sri Lanka Institute of Advanced Technological Education (SLIATE) asked students to discuss how their phones affect their education. Many students spoke positively about how their phones influence their intellectual development, with one student saying their phone “broadens my learning beyond the classroom and enriches my understanding of subjects”, and another stating “I believe it enhances my academic performance”.

“I used to struggle with organizing my study materials, but with my smartphone, I feel more in control. I can access resources anytime, anywhere”

A student in Sri Lanka expressing how using her phone has vastly improved her studies

Positive opinions are not limited to students either, with another study in 2022 interviewing university staff reporting more advantages of cellphone use for students such as the improved accessibility of online resources and the benefits of increased connectivity with classmates. Even parents are starting to realize some positive aspects of cellphone use in their children. Authors of a 2021 paper explored parents’ attitudes towards cellphone use; despite the overarching theme of anxiety around allowing young children to use phones, parents appeared to understand there are benefits to embracing advancing technology. One parent recalling how her 8-year-old is benefitting from using a phone: “I have noticed that the English language of my son has improved, and I have realised that this is because of using applications and searching the internet.”

Exercise is undeniably a constructive way for teenagers to spend their downtime, benefiting both their mental wellbeing and academic performance. At the same time, excessive cellphone use is a growing concern, with many students turning to their devices as a way of coping with academic pressure. Yet the evidence suggests that cellphones are not inherently harmful. They can connect students with friends, educational resources, fitness communities, and sources of support that were unimaginable a generation ago.

Perhaps the real question is not whether teenagers should use cellphones, but what cellphones are replacing. When screen time displaces exercise, sleep, face-to-face interaction, or other activities that actively support wellbeing, the consequences can be significant. However, when used in moderation and alongside healthy habits, cellphones can be a valuable tool rather than an obstacle. The challenge, therefore, is not to eliminate technology from young people's lives, but to ensure it does not come at the expense of the activities that help them thrive.