article 2019 Motivation in the Athens Classic Marathon: The Role of Sex, Age, and Performance Level in Greek Recreational Marathon Runners Pantelis T. Nikolaidis, Aïna Chalabaev, Thomas Rosemann, Beat Knechtle JournalInternational Journal of Environmental Research and Public HealthDOI10.3390/ijerph16142549Populationrecreational marathon runners View on DOI ↗