Boasting toned calves and thighs, runners' legs are coveted by most athletes. Walking, which is a low-intensity exercise that is often used as a substitute for running, works many of the same muscles. In this case, the overall intensity of the exercise does not matter as it is possible to get those svelte runner legs through walking.
Biomechanics of the Exercises
Both running and walking use three main muscle groups in the legs. The hamstrings, quadriceps and gluteal muscles support the motion of propelling your body forward by putting one foot in front of the other. The biggest difference between the two exercises is the impact and intensity. Running is a high-impact, high-intensity exercise because of the effort exerted and the force your body absorbs. Walking doesn't require as much work or force, making it a low-impact, low-intensity exercise.
A study by Kotaro Sasaki at the University of Texas found that muscles support propulsion in a similar manner in walking and running, concluding that you can develop runner's legs from walking. It is important to note that runners develop toned quadriceps, hamstrings and gluteal muscles by pounding out miles upon miles. For walkers to experience the same benefits, they must log similar mileage.