Which suggestions for behavioral modifications, based on mathematical models, are most likely to be followed in the real world? We address this question in the context of human circadian rhythms. Jet lag is a consequence of the misalignment of the body’s internal circadian (~24-hour) clock during an adjustment to a new schedule. Light is the clock’s primary synchronizer. Previous research has used mathematical models to compute light schedules that shift the circadian clock to a new time zone as quickly as possible. How users adjust their behavior when provided with these optimal schedules remains an open question. Here, we report data collected by wearables from more than 100 travelers as they cross time zones using a smartphone app, Entrain. We find that people rarely follow the optimal schedules generated through mathematical modeling entirely, but travelers who better followed the optimal schedules reported more positive moods after their trips. Using the data collected, we improve the optimal schedule predictions to accommodate real-world constraints. We also develop a scheduling algorithm that allows for the computation of approximately optimal schedules "on-the-fly" in response to disruptions. User burnout may not be critically important as long as the first parts of a schedule are followed. These results represent a crucial improvement in making the theoretical results of past work viable for practical use and show how theoretical predictions based on known human physiology can be efficiently used in real-world settings.

在现实世界中，最有可能遵循哪些基于数学模型的行为修改建议？我们在人类昼夜节律的背景下解决这个问题。时差是新的时间表调整期间人体内部生物钟（约24小时）未对准的结果。灯光是时钟的主要同步器。先前的研究已使用数学模型来计算灯光调度，以将生物钟尽快移至新的时区。当提供这些最佳计划时，用户如何调整其行为仍然是一个悬而未决的问题。在这里，我们报告了可穿戴设备通过智能手机应用程序Entrain从超过100个旅行者跨越时区收集的数据。我们发现人们很少完全遵循通过数学建模生成的最优时间表，但是更好地遵循最优时间表的旅行者在出行之后就表现出更多的积极情绪。使用收集到的数据，我们改进了最佳时间表预测，以适应现实世界中的限制。我们还开发了一种调度算法，该算法可根据中断情况“即时”计算近似最佳的调度。只要遵循时间表的第一部分，用户的倦怠就不是至关重要的。这些结果代表了使过去工作的理论结果切实可行的关键改进，并显示了如何将基于已知人类生理学的理论预测有效地用于现实环境。