Physical education (PE) has long been championed as a lever for healthier, more active kids—but how much extra movement does PE really buy, and what happens once the weekend rolls around? A six-week study of 221 U.S. middle school students wearing wrist accelerometers offers some clear signals for teachers, parents, and policymakers. Below is a concise look at the findings, followed by a deeper dive into the results and discussion.
Key takeaways
School days—PE or not—beat Sundays hands down. Students logged roughly 2,100–2,450 more steps on PE and regular school days than on Sundays.
Activity fades fast after the first week. A novelty spike in Week 1 (when students first received the devices) was followed by a steady decline of about 1,350 steps by Week 6.
Girls hit national step targets only on PE days. The 11,000-step benchmark was met (or nearly met) five of six PE days, but rarely on non-PE or weekend days; boys never reached their 13,000-step goal.
Weekends are the weak link—especially Sundays. Three-quarters of weekend days fell below the 10,000–11,700-step range linked to 60 minutes of moderate to vigorous physical activity (MVPA).
Eighthgraders and allgirl classes lag behind. The oldest cohort recorded the lowest activity, and an allfemale PE class clocked 3,900–5,000 fewer steps than peers.
Less PE time, less progress. None of the participating schools met the recommended 225 minutes of PE per week; most offered just 90–150 minutes.
Results in focus
Overall steps and daytype differences
Across 12 classes, daily steps ranged from a high of 14,651 on Week 1 non-PE days to a low of 8,536 on a Week 5 Sunday. A repeated-measures ANOVA confirmed a significant main effect for Type of Day: students were considerably more active on non-PE and PE days than on Sundays (mean difference ≈ 2,150–2,450 steps, p < .05). Saturdays fell between the two extremes and did not differ significantly from weekdays.
Time trend
Week 1 enthusiasm inflated activity counts—likely a “gadget effect” as students experimented with the accelerometers. By Week 5 and Week 6, average steps had dropped by 1,140 and 1,353, respectively (p < .05).
Sex and grade-level patterns
Although boys typically take more steps, sex differences were not statistically significant overall. The important nuance: girls met or neared the 11,000-step guideline on five of six PE days but seldom elsewhere, underscoring PE’s outsized role for adolescent girls. Eighth-graders posted the lowest counts, echoing broader evidence that activity declines with age.
The Sunday slump
Sundays were the least active, mirroring prior research that links the day to limited organized sport options and more sedentary screen time. The authors suggest schools and communities compensate by bolstering weekday PE and afterschool programs.
Discussion highlights
PE’s protective effect, especially for girls. When PE was on the timetable, girls reliably crossed the 11,000-step threshold; without it, they rarely did. As daily PE declines nationally, this finding rings alarm bells for equity in activity opportunities.
Weekend interventions are essential. Because 75 % of weekend days failed to reach MVPA-equivalent steps, after-school or community programs, particularly on Sundays, could plug a major activity gap.
Technology’s motivational fizz. The Week 1 surge hints that wearables can spark movement—but only briefly. Curricula that weave accelerometer feedback into lessons (e.g., the study’s F.I.T. unit) or gamify long-term goals may help sustain interest.
All-girl PE requires careful design. The single-sex class trailed mixed peers at every measurement, aligning with earlier studies showing less MVPA in girls-only settings. More engaging, choice rich curricula could counteract this dropoff.
Bottom line
A single PE lesson won’t fix adolescent inactivity, but it clearly nudges the needle—particularly for girls. The bigger challenge is extending that momentum beyond the gym and into weekends, where activity plummets. Schools can start by protecting PE minutes, embedding wearable tech in lessons, and partnering with community programs to make Sundays as active as Wednesdays.
Full Article:
Marttinen, R., Fredrick III, R., & Silverman, S. (2018). Middle school students’ free-living physical activity on physical education days, non-physical education days, and weekends. Montenegrin Journal of Sports Science and Medicine, 7(1), 5-12. https://doi.org/10.26773/mjssm.180301
This blog post was written with the assistance of AI to support clarity and accessibility. It is intended to help disseminate and discuss research findings with a broader audience. However, for the most accurate and reliable information—including conclusions and practical applications—please refer to the original peer-reviewed publication on which this blog is based. The peer-reviewed article remains the most authoritative source.