Background

Optimal nutrition is highly valuable for athletes aiming at maintaining or improving body composition and sports performance. When combined with structured exercise, time-restricted energy intake may represent an effective non-pharmacological approach to achieve these results.

Objective

The aim of this study was to investigate the effects of four weeks of time-restricted eating (TRE) vs. four weeks of habitual diet on aerobic capacity, body composition and metabolic health in 18-30 years old males accustomed to endurance running.

Design

This trial utilized a randomized-crossover study design. Participants completed graded exercise tests, body composition scans and fasting blood samples before and after each intervention condition.

Participants/setting

Sixteen male physical-education students were recruited and enrolled in the study from the Faculty of Human Kinetics - University of Lisbon in September 2020, in Lisbon, Portugal. One participant was excluded post-one week due to a lack of adherence to the study protocol. Therefore, fifteen participants completed the study and were involved in the final analysis.

Intervention

During the TRE condition, participants consumed two to three meals within an 8-hour eating window (between 1 and 9 p.m.). Only water, tea and coffee (without caloric additives) were permitted to be consumed in the remaining 16 hours per 24-hour time period. During the non-TRE condition, participants consumed their habitual diet without any timing restrictions. The order of the TRE intervention and the habitual diet condition was randomized and counterbalanced, and participants served as their own controls. The participants followed a structured training routine during each dietary condition.

Main outcome measures Body composition variables, indices of running aerobic capacity and markers of metabolic health were assessed.

Statistical analyses performed One-way repeated measures analysis of variance and covariance were performed to analyse differences between conditions and time with each intervention.

Results

Neither condition elicited observed changes in total body mass, fat mass nor fat-free mass between time points. Moreover, no significant changes were observed for markers of metabolic health. Significant improvements were obtained with both conditions for the first ventilatory threshold, maximum oxygen uptake (VO_2max) and velocity at VO_2max (p<0.05).

Conclusions

Four weeks of endurance running and TRE, compared to four weeks of endurance running and a habitual diet, in healthy trained 18-30-year-old male recreational runners did not result in observed differences in total body mass, fat mass or fat-free mass. In addition, TRE did not offer any additional benefit for improving submaximal or peak exercise capacity in this population.

中文翻译：

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限时饮食对健康男性休闲跑步者有氧能力、身体成分和代谢健康指标的影响：一项随机交叉试验

背景

最佳营养对于旨在维持或改善身体成分和运动表现的运动员非常有价值。当与结构化运动相结合时，限时能量摄入可能是实现这些结果的有效非药物方法。

客观的

本研究的目的是调查 4 周的限时饮食 (TRE) 与 4 周的习惯性饮食对习惯耐力跑的 18-30 岁男性的有氧能力、身体成分和代谢健康的影响。

设计

该试验采用了随机交叉研究设计。参与者在每种干预条件之前和之后完成了分级运动测试、身体成分扫描和空腹血液样本。

参与者/设置

2020 年 9 月，里斯本大学人类动力学学院在葡萄牙里斯本招募了 16 名男性体育学生并参加了这项研究。由于不遵守研究方案，一名参与者在一周后被排除。因此，十五名参与者完成了研究并参与了最终的分析。

干涉

在 TRE 条件下，参与者在 8 小时的进食窗口（下午 1 点到 9 点之间）内吃了两到三餐。每 24 小时的剩余 16 小时内只允许饮用水、茶和咖啡（不含热量添加剂）。在非 TRE 条件下，参与者按照习惯饮食，没有任何时间限制。TRE 干预的顺序和习惯性饮食条件是随机和平衡的，参与者作为自己的对照。参与者在每种饮食条件下都遵循结构化的训练程序。

主要结果指标评估了身体成分变量、跑步有氧能力指数和代谢健康指标。

进行统计分析进行单向重复测量方差和协方差分析，以分析每次干预的条件和时间之间的差异。

结果

这两种情况都没有在时间点之间引起观察到的总体质量、脂肪质量或去脂质量的变化。此外，代谢健康指标没有观察到显着变化。_{第一通气阈值、最大摄氧量 (VO 2max} ) 和 VO _2max时的速度(p<0.05)均获得显着改善。

结论

与四个星期的耐力跑和习惯性饮食相比，接受过四个星期的耐力跑和 TRE 训练的健康训练有素的 18-30 岁男性休闲跑步者在总体质量、脂肪质量或去脂体重方面没有观察到差异大量的。此外，TRE 并没有为提高该人群的次最大或峰值运动能力提供任何额外的益处。