The energetics of walking on sand and grass at various speeds

This study investigated the energetics of walking on sand and grass. Fourteen adult males, participated in the study. Participants had a mean age of 34.6 years old, 72.6 kg in mass and 172.5 cm in stature, who walked at 3, 4, 5, 6 and 7 km per h on sand and grass surfaces. Physiological measures included heart rate, O(2) uptake, CO(2) exhalation, ventilation and relative O(2) uptake using a MetaMax Ergospirometer. Speed was controlled in a methodology similar to the 'Multistage 20-m Shuttle Run Test'. Data were collected during physiological steady rate at each determined speed. A minimum of 2 h rest was enforced between randomized conditions. Results indicate that there was a significant increase (p < 0.01) in all measured physiological indices indicative of energy expenditure when walking on sand compared to grass at 3-7 km per h, with the greatest disparity between the surfaces (ratio = 1.63) in relative O(2) consumption at 5 km per h.