Trail runners differ from running shoes and hiking shoes. A trail running shoe is designed for running on unpaved trails. There are usually rocks and uneven terrain on a trail, and the running shoe must provide stability and protection for the foot while being flexible enough to allow for running.
A trail runner will have flexibility and ease of motion in the front of the shoe. To test a trail runner, bend the front of the shoe up and down. It should flex easily. In order to prevent ankle strain, the trail running shoe will be stiff if twisted. This is because the shoe is designed to prevent pronation or rocking of the foot from side to side as the runner takes strides along the trail.
Trail runners must be lightweight to allow for maximum performance. A heavy shoe would slow a runner and cause undue stress on the foot and joints. Most trail shoes are not water resistant, and the uppers are made from mesh or other lightweight materials.
Hiking shoes are low cut styles of hiking boots. The soles are heavier than a trail shoe or sneaker. Vibram soles are a common material, but there are other materials as well. Hiking shoes are usually waterproof or water resistant. Gortex is a common material for insulating and waterproofing. A hiking shoe will protect your foot from brambles, rocks and other hazards along the trail. It is a shoe that is designed for walking or climbing, not running. Insulated hiking shoes are used for hiking in cold weather. Common insulating materials are Thinsulate or Gortex. Some hiking shoes have leather uppers; others have suede or cloth.
Choose a trail runner as a lightweight shoe designed for running over sand, dirt, gravel or dry stream beds. Trail runners are not insulated or water resistant. Look for features like no-tie laces that tighten with a sliding mechanism. Mesh uppers will allow for maximum air flow at the expense of reduced foot protection.
Hiking shoes are a good choice for day hikes or short overnight treks. It is a heavier shoe that is lighter than a full-cut or mid-cut hiking boot, but it is sturdier than a trail runner. The soles are stronger and have less flex in the front of the shoe than a trail runner. Insulated, waterproof and water resistant options are available for hiking in wet and cold weather.