The Questionnaire on Perceived Load and Fatigue serves to assess the experienced strain during the past hour as well as the currently perceived fatigue, each with one item. This is assessed across three domains: cognition, motor / physical domain, and emotions. The QLF-S was developed for use during load capacity testing. The questionnaire has so far been used in a study involving 73 patients with post-COVID syndrome and a healthy control sample of 58 gender- and age-matched individuals. The study was conducted between 2022 and 2024 (Tempfli et al. & Randerath, 2025, submitted). The development of the original questionnaire in German (FBE-S: Fragebogen zu empfundener Belastung und Erschöpfung (Status)) was funded by the Zukunftskolleg of the University of Konstanz. The implementation of the study was supported by the Ministry of Science, Research and the Arts of Baden-Württemberg. The English translation "QLF-S: Questionnaire on Perceived Load and Fatigue (State)" was created at the University of Regensburg in 2025.