"did not enhance any performance parameter (peak power, average power, and FI) in later sprint sets." The researchers concluded that "Based on the results found in this study, we do not recommend applying this method with the view of improving performance, at least not for repeated sprinting." In 2022, a pilot study titled The Effects of Cold Exposure Training and a Breathing Exercise on the Inflammatory Response in Humans showed that:"The combination of cold exposure training and a breathing exercise most potently attenuates the in vivo inflammatory response in healthy young males. Our study demonstrates that the immunomodulatory effects of the intervention can be reproduced in a standardized manner, thereby paving the way for clinical trials." A 2022 study found that a "4 week intervention exercise based on the pillar of the Wim Hof breathing method was not effective in improving the breathing economy of adolescent elite endurance runners." The authors recommended proven interventions such as yogic breath training instead. Method-related deaths At least nine people have died while attempting the Wim Hof Method. Four practitioners drowned in 2015 and 2016, and relatives suspected the breathing exercises were to blame. In 2021, a Singaporean man drowned in a condominium pool when attempting the method. At least one person has died from a heart attack after cold-water immersion. The leading cause of death with Wim Hof Method-related activities seems to be shallow water blackout where practitioners hyperventilate in or around water and unexpectedly lose consciousness. Though Wim Hof's safety video explicitly states doing breathwork in water is dangerous, Wim Hof has been filmed teaching deep-breathing techniques to instructors in water as late as 2023. Records and stunts In an interview with Rolling Stone, Hof claimed to have acquired a total of 26 world records, though no systematic evaluation of these records is listed anywhere. Fastest half-marathon barefoot on ice and snow The fastest half marathon run while barefoot on ice or snow is 2 hr 16 min 34 sec by Hof near Oulu, Finland, on 26 January 2007. Done for the Discovery Channel program Real Super-humans and the Quest for the Future Fantastic, this is the only current Guinness record in Hof's name. Swimming under ice On 16 March 2000, Hof set the Guinness World Record for farthest swim under ice on his second attempt, with a distance of . Hof's first attempt the day before failed when he began his