Wellcome Centre For Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
Department of Sport Health Sciences and Social Work, Centre for Movement Occupational and Rehabilitation Sciences, Oxford Brookes Centre for Nutrition and Health, Oxford Brookes University, Oxford, OX3 0BP, UK.
Int J Behav Nutr Phys Act. 2021 Mar 31;18(1):47. doi: 10.1186/s12966-021-01113-y.
Physical activity (PA) may positively stimulate the brain, cognition and mental health during adolescence, a period of dynamic neurobiological development. High-intensity interval training (HIIT) or vigorous PA interventions are time-efficient, scalable and can be easily implemented in existing school curricula, yet their effects on cognitive, academic and mental health outcomes are unclear. The primary aim of the Fit to Study trial was to investigate whether a pragmatic and scalable HIIT-style VPA intervention delivered during school physical education (PE) could improve attainment in maths. The primary outcome has previously been reported and was null. Here, we report the effect of the intervention on prespecified secondary outcomes, including cardiorespiratory fitness, cognitive performance, and mental health in young adolescents.
The Fit to Study cluster randomised controlled trial included Year 8 pupils (n = 18,261, aged 12-13) from 104 secondary state schools in South/Mid-England. Schools were randomised into an intervention condition (n = 52), in which PE teachers delivered an additional 10 min of VPA per PE lesson for one academic year (2017-2018), or into a "PE as usual" control condition. Secondary outcomes included assessments of cardiorespiratory fitness (20-m shuttle run), cognitive performance (executive functions, relational memory and processing speed) and mental health (Strength and Difficulties Questionnaire and self-esteem measures). The primary intention-to-treat (ITT) analysis used linear models and structural equation models with cluster-robust standard errors to test for intervention effects. A complier-average causal effect (CACE) was estimated using a two-stage least squares procedure.
The HIIT-style VPA intervention did not significantly improve cardiorespiratory fitness, cognitive performance (executive functions, relational memory or processed speed), or mental health (all p > 0.05). Subgroup analyses showed no significant moderation of intervention effects by sex, socioeconomic status or baseline fitness levels. Changes in cardiorespiratory fitness were not significantly related to changes in cognitive or mental health outcomes. The trial was marked by high drop-out and low intervention compliance. Findings from the CACE analysis were in line with those from the ITT analysis.
The one-academic year HIIT-style VPA intervention delivered during regular school PE did not significantly improve fitness, cognitive performance or mental health, but these findings should be interpreted with caution given low implementation fidelity and high drop-out. Well-controlled, large-scale, school-based trials that examine the effectiveness of HIIT-style interventions to enhance cognitive and mental health outcomes are warranted.
ISRCTN registry, 15,730,512 . Trial protocol and analysis plan for primary outcome prospectively registered on 30th March 2017. ClinicalTrials.gov , NCT03286725 . Secondary measures (focus of current manuscript) retrospectively registered on 18 September 2017.
在青少年时期，身体活动（PA）可能会积极刺激大脑、认知和心理健康，这是一个神经生物学快速发展的时期。高强度间歇训练（HIIT）或剧烈的 PA 干预是高效的、可扩展的，可以很容易地纳入现有的学校课程，但它们对认知、学业和心理健康结果的影响尚不清楚。“Fit to Study”试验的主要目的是研究在学校体育教育（PE）期间进行实用且可扩展的 HIIT 式 VPA 干预是否可以提高数学成绩。主要结果之前已经报告过，结果为无效。在这里，我们报告干预对预先指定的次要结果的影响，包括心肺健康、认知表现和青少年的心理健康。
“Fit to Study”整群随机对照试验纳入了来自英格兰南部/中部 104 所中学的 18261 名 8 年级学生（年龄 12-13 岁）。学校被随机分为干预组（n=52），在一个学年（2017-2018 年）中，体育教师在每节体育课中额外增加 10 分钟的 VPA；或分为“常规体育课”对照组。次要结果包括心肺健康评估（20 米穿梭跑）、认知表现（执行功能、关系记忆和处理速度）和心理健康（困难与强项问卷和自尊量表）。主要的意向治疗（ITT）分析使用线性模型和结构方程模型，采用集群稳健标准误差来检验干预效果。使用两阶段最小二乘法程序估计遵从平均因果效应（CACE）。
HIIT 式 VPA 干预并未显著提高心肺健康、认知表现（执行功能、关系记忆或处理速度）或心理健康（均 p>0.05）。亚组分析表明，性别、社会经济地位或基线健康水平对干预效果没有显著的调节作用。心肺健康的变化与认知或心理健康结果的变化没有显著关系。该试验因高辍学率和低干预依从性而受到限制。CACE 分析的结果与 ITT 分析的结果一致。
在常规学校体育课中进行为期一学年的 HIIT 式 VPA 干预并没有显著提高学生的健康水平、认知表现或心理健康水平，但鉴于实施保真度低和高辍学率，这些发现应谨慎解释。需要进行精心控制、大规模、以学校为基础的试验，以检验 HIIT 式干预对增强认知和心理健康结果的有效性。
ISRCTN 注册处，15730512。主要结果的试验方案和分析计划于 2017 年 3 月 30 日前瞻性注册。临床Trials.gov，NCT03286725。次要措施（本研究重点）于 2017 年 9 月 18 日回顾性注册。
