Which surface is identified as having the lowest impact on the feet while running?

Grass surfaces are recognized for having the lowest impact on the feet while running due to their natural cushioning properties. This type of surface provides a softer landing compared to harder surfaces like pavement and cement, which can contribute to higher forces being transferred up through the feet and legs with each stride. The elasticity of grass helps absorb energy, reducing the strain on joints and muscles.

In addition, grass surfaces are generally more forgiving, allowing for better traction than muddy or uneven dirt trails, although those can vary in impact based on conditions. Consequently, the combination of cushioning and traction makes grass a favorable choice for those concerned about reducing impact-related injuries while running.