A standard lightweight, moderate-speed bicycle is one of the most energy-efficient forms of transport. Compared with walking, a 64 kg (140 lb) cyclist riding at 16 km/h (10 mph) requires about half the food energy per unit distance: 27 kcal/km, 3.1 kW·h (11 MJ) per 100 km, or 43 kcal/mi.