A Study to Evaluate the Analgesic Properties of Topically Applied Menthol in Marathon Participants

This observational, real-world evidence study will evaluate pain relief, sensory attributes, and quality-of-life outcomes among adult (18+ years) runners participating in the 2026 Chicago Marathon who independently choose to use Biofreeze at the end of the marathon in the Recovery Zone, or after the race. Biofreeze products are available to runners irrespective of study participation, and participants independently decide whether to use Biofreeze and which product format to use. The study will collect information through two questionnaires: End of Race Questionnaire completed in the Recovery Zone immediately following the marathon and Post-Race Questionnaire completed after the race. Data collected through the two questionnaires will not be linked. Participants will provide separate informed consent before completing each questionnaire. For the End of Race Questionnaire, runners who independently enter the Recovery Zone and choose to use Biofreeze will be invited to participate. After providing informed consent, participants will report their pain intensity before applying their selected Biofreeze product and after application using a Numerical Rating Scale (NRS). Information on product format, pain location, cooling sensation and related sensory attributes, and demographic characteristics will also be collected. The primary evaluation will assess the analgesic effect of topically applied menthol gel and roll-on formulations in the Recovery Zone, based on changes in participant-reported NRS pain scores. Secondary evaluations will assess clinically meaningful reduction in pain, sensory attributes associated with product use, sensory attributes, pain-relieving effects of Biofreeze used during and/or after the marathon, and recovery- and sleep-related quality-of-life outcomes. The Post-Race Questionnaire will collect participant-reported information on Biofreeze use during and/or after the marathon, including pain relief, sensory attributes, duration of pain relief, and perceived effects on performance, recovery, and sleep-related outcomes, as well as demographic characteristics.