167869 20260121151420.0 doi 10.3389/fphys.2025.1709093 sideral 147554 ART-2025-147554 eng Schobersberger, Wolfgang Thermoregulatory responses in elite cross-country skiers during international competitions and training 2025 Background. The aim of this study was to describe the thermoregulatory responses of elite athletes during competitions and training of the international cross-country skiing FIS Scandinavian Cup in Finland, held under cold (subzero) ambient conditions. Methods The core and skin temperatures were continuously recorded during two competition formats—a 10-km race (n = 18; 10 m, 8 f) and a 20-km race (n = 14; 9 m, 5 f)—and during training (n = 11; 7 m, 4 f) using electronic temperature pills and temperature sensors fixed on the chest, arm, hand, and thigh, respectively. The heart rate and skiing speed were continuously recorded using heart rate monitors with integrated GPS technology. Ambient temperatures during the measuring period ranged from −13.0 °C to −1.3 °C. Results The mean core temperature (Tcore) increased significantly during the 10-km classic (39.0 °C ± 0.4 °C) and the 20-km freestyle (39.2 °C ± 0.7 °C) races (all p < 0.001) and during trainings (38.3 °C ± 0.5 °C). In contrast, skin temperature decreased in all four body parts (all p < 0.001), with the greatest decreases measured on the thigh [18.7 °C ± 4.1 °C (10-km race), 20.7 °C ± 4.6 °C (20-km race), and 18.5 °C ± 3.2 °C (training)]. During both races, the heart rate significantly increased over time while the racing speed decreased (p < 0.001, respectively). The mean skin temperature of the thigh correlated with skiing speed in the 10-km (r = 0.573, p = 0.041) and the 20-km (r = 0.682, p = 0.021) races. Conclusion: In summary, despite low ambient temperatures under real competition and training conditions, the athletes exhibited high heat generation, which enabled them to maintain a high core temperature. In contrast, the skin temperature dropped sharply during competitions and trainings. The association between the low mean skin temperature and the lower racing speed should be investigated further. Access copy available to the general public Unrestricted info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Valtonen, Maarit Köck, Anika Racinais, Sebastien Pitsiladis, Yannis Verdoukas, Panagiotis Muñiz-Pardos, Borja Universidad de Zaragoza (orcid)0000-0002-9191-9033 Mäki-Heikkilä, Rikhard Ihalainen, Johanna K. Gagnon, Dominique Dünnwald, Tobias 1006 245 Universidad de Zaragoza Dpto. Fisiatría y Enfermería Área Educación Física y Depor. 16 (2025), [12 pp.] Front. physiol. Frontiers in physiology 1664-042X 424721 http://zaguan.unizar.es/record/167869/files/texto_completo.pdf Versión publicada 2398165 http://zaguan.unizar.es/record/167869/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:167869 articulos driver 2026-01-21-14:55:18 ARTICLE