Travelling athletes experience travel fatigue and jet lag that intensify their subjective burden and may influence performance and increase illness and injury risk.
The consensus group also outlined specific steps to advance theory and practice in these areas. These are summarised in travel toolboxes including strategies for pre-flight, during flight and post-flight.
The lack of evidence restricts the strength of recommendations that are possible but the consensus group identified the fundamental principles and interventions to consider for both the assessment and management of travel fatigue and jet lag. This manuscript includes definitions of terminology commonly used in the field of circadian physiology, outlines basic information on the human circadian system and how it is affected by time-givers, discusses the causes and consequences of travel fatigue and jet lag, and provides consensus on recommendations for managing travel fatigue and jet lag in athletes. Therefore 26 researchers and/or clinicians with knowledge in travel fatigue, jet lag and sleep in the sports setting, formed an expert panel to formalise a review and consensus document. Despite considerable agreement that travel fatigue and jet lag can be a real and impactful issue for athletes regarding performance and risk of illness and injury, evidence on optimal assessment and management is lacking. Sports Medicine volume 51, pages 2029–2050 ( 2021) Cite this articleĪthletes are increasingly required to travel domestically and internationally, often resulting in travel fatigue and jet lag. We conclude by specifying the conditions under which lagged explanatory variables are appropriate responses to endogeneity concerns.Managing Travel Fatigue and Jet Lag in Athletes: A Review and Consensus Statement We then use Monte Carlo simulations to show how, even under favorable conditions, lag identification leads to incorrect inferences. We build our argument intuitively using directed acyclic graphs and then provide analytical results on the bias of lag identification in a simple linear regression framework. We show that lagging explanatory variables as a response to endogeneity moves the channel through which endogeneity biases parameter estimates, supplementing a “selection on observables” assumption with an equally untestable “no dynamics among unobservables” assumption.
There exist surprisingly few formal analyses or theoretical results, however, that establish whether lagged explanatory variables are effective in surmounting endogeneity concerns and, if so, under what conditions.
Lagged explanatory variables are commonly used in political science in response to endogeneity concerns in observational data.