スペインの青年を対象とした学校ベースのサイクリング介入が学校への通学行動およびデバイスで測定された活動に及ぼす影響：PACOクラスター無作為化比較試験

Active commuting to/from school (ACS) is associated with multiple health and societal benefits, yet school-based interventions have shown limited success in changing adolescents' commuting behavior, and their effects on psychosocial factors remain unclear. This study primarily examined the effects of a school-based cycling intervention on the usual mode and frequency of ACS, and ACS-related psychosocial outcomes in Spanish adolescents. Secondary outcomes included device-measured sedentary time and physical activity (PA).

A cluster-randomized controlled trial was conducted in eight Spanish secondary schools. A total of 256 adolescents (45.7% girls; mean age 14.4 years) were allocated to an intervention (n = 127) or control group. The intervention consisted of four weekly sessions delivered during Physical Education classes over one month, combining cycling theory, skills training in closed circuits, and supervised on-road cycling in urban environments. Outcomes were assessed at baseline and post-intervention and included usual mode and weekly frequency of ACS, perceived barriers to ACS, basic psychological need satisfaction in ACS, motivation for ACS, and device-measured sedentary time and PA across daily segments.

No significant between-group effects were observed for usual mode or frequency of ACS, nor for device-measured sedentary time or PA. Most psychosocial outcomes did not differ between groups. However, perceived environmental/safety barriers increased in the intervention group compared with controls (Δ = 0.22, p = 0.041). Moderation analyses showed that girls in the intervention group reported greater increases in amotivation for ACS than girls in the control group (Δ = 0.54, p = 0.018). Per-protocol analyses revealed higher external motivation (Δ = 0.40, p = 0.029) and amotivation (Δ = 0.38, p = 0.037) in the intervention group, with stronger effects among girls and adolescents from higher socioeconomic backgrounds.

The school-based cycling program did not change the commuting behavior or device-measured activity. Instead, participation was associated with increased awareness of environmental/safety barriers and higher amotivation, particularly among girls. Per-protocol analyses also revealed increases in external motivation and perceived barriers, particularly among girls and high-SES adolescents. These findings suggest that short-duration, skills-focused cycling interventions may heighten perceived constraints without being sufficient to support behavior change. Future programs may require longer duration, autonomy-supportive delivery, and complementary built environmental and family-level strategies to effectively promote ACS among adolescents.

ClinicalTrials.gov (Identifier: NCT03937336).