The Influence of Backpack-Design on Thermophysiological Parameters during Simulated Hiking Activities

To assess the thermoregulatory capacities of backpack-designs, five male participants were equipped with a temperature and moisture measuring system. Relative humidity (rH) and temperature (T) were measured underneath the participants’ t-shirt—microclimate (MC)—and between shirt and backpack—interlayer climate (ILC). Participants completed a test protocol simulating a hiking exercise in three conditions in a randomized order: (W) without backpack and (B1-B2) with each of the backpacks (total weight: 5.4 kg). The test-protocol consisted of a 5-min rest, 10-min walk at 4 km/h without gradient, 15-min walk at 4 km/h with 8% incline, and a final 10-min rest. Results showed that the temperature and absolute humidity (aH) values generally decreased from the microclimate to the interlayer climate. Differences of up to ΔT = 1.27 °C and ΔaH = 2.55 g/m3 in the microclimate of the upper back area were observed for different backpack designs, indicating the influence of backpack design on thermoregulation.