Pinedo Jauregi, AitorQuinn, Tyler D.Coca Núñez, AitorMejuto Hidalgo, GaizkaCámara Tobalina, Jesús Árbol2025-05-222025-05-222022-04-27Pinedo-Jauregi, A., Quinn, T., Coca, A., Mejuto, G., & Cámara, J. (2022). Physiological stress in flat and uphill walking with different backpack loads in professional mountain rescue crews. Applied Ergonomics, 103. https://doi.org/10.1016/J.APERGO.2022.1037840003-687010.1016/J.APERGO.2022.103784http://hdl.handle.net/20.500.14454/2810This study aimed to determine the interactive physiological effect of backpack load carriage and slope during walking in professional mountain rescuers. Sixteen mountain rescuers walked on a treadmill at 3.6 km/h for 5 min in each combination of three slopes (1%, 10%, 20%) and five backpack loads (0%, 10%, 20%, 30%, and 40% body weight). Relative heart rate (%HRmax), relative oxygen consumption (%VO2max), and rating of perceived exertion (RPE, Borg 1–10 scale) were compared across conditions using two-way ANOVA. Significant differences in %VO2max, %HRmax, and RPE across slopes and loads were found where burden increased directly with slope and load (main effect of slope, p < 0.001 for all; main effect of load, p < 0.001 for all). Additionally, significant slope by load interactions were found for all parameters, indicating an additive effect (p < 0.001 for all). Mountain rescuers should consider the physiological interaction between slope and load when determining safe occupational walking capacity.eng© 2022 The AuthorsBackpack and slope walkingLoad carriagePhysical work capacityPhysiologyjournal article2025-05-221872-9126