Ryan SmithHiking boots vs trail runners: Each has its strengths and weaknesses, depending on the intended use.

Ever hear that an extra pound on your feet is equivalent to 5 pounds on your back? Whether or not that oft-quoted piece of backcountry wisdom is exactly right, one thing is definitely true: Hiking requires less effort in lightweight footwear. And therein lies the allure of wearing trail running shoes instead of heavier hiking boots. But is it really safe to do so?

Hiking footwear must accomplish two primary tasks. First, it must provide adequate ankle support to prevent sprains and injury. Second, it must protect your feet from the abuses of the environment. And those two factors vary considerably depending on the terrain, the weight of your pack, and the inherent stability of your ankles.

Trail Runner Basics
A trail runner is essentially a beefier version of a running shoe. It features a tread designed to provide traction on rock and dirt trails, plus greater torsional rigidity—a measure of how stiff the shoe is when twisted side-to-side—than a normal running shoe. Most styles are cut below the ankle and weigh between 18 to 24 ounces per pair. Like boots, some models feature Gore-Tex or the equivalent, which provides waterproofness at the expense of ventilation. They run $100 to $150.

Hiking Boot Basics
Hiking boots feature a high ankle collar and a range of torsional rigidity, from extremely stiff to very flexible. (Check this by holding the front of the boot in one hand, the heel in the other, and twisting it from side-to-side.) The tread is typically made from a harder, more durable rubber than that used on trail runners, and the boots’ upper portion features a range of materials, from all leather to a variety of leather-fabric-mesh combinations. Weight and price vary substantially, though a typical pair of all-purpose midweight boots hovers in the 2- to 3-pound range (up to 4 pounds for heavy-duty styles) and costs roughly $150 to $250, with all-leather boots falling in the upper end of this range.

Evaluating Ankle Support
When it comes to ankle support, the most important factor is torsional rigidity—a stiffer shoe provides a more stable platform underfoot. A higher ankle collar increases support as well but is of secondary importance. Another key factor is fit; your feet should not slip from side-to-side inside your shoes.

Hiking terrain plays a significant role in footwear selection. Rough and uneven trails merit extra ankle support, while easy to moderate terrain requires less. Another crucial factor is pack weight. Heavier loads create additional pressure on the ankles, increasing the importance of proper support. Lastly, consider the stability of your ankles. Do you have flexible ankles with a history of twists and sprains? Or are they strong and injury-free?

When it comes to maximizing ankle support, hiking boots win out. But a hiking boot can also be overkill, especially if you’re traveling over gentle to moderate terrain with a light pack and have strong, injury-free ankles. In this situation, a trail runner is generally a safe choice.

Protect Yourself
Low-cut trail runners expose your ankles to the abuses of the environment, a concern if you’re hiking in rocky terrain, bushwhacking through dense brush, or dealing with ankle-deep mud puddles. Adding gaiters over a pair of trail runners can help, but only a full ankle collar maximizes protection. Also consider the terrain underfoot. Trail runners feature a softer sole that will not fully protect your feet from sharp rocks or other pressure points. If you’re traveling over scree, talus, or other rocky terrain, this can bruise the undersides of your feet—and lead to a very painful hiking experience that could have been avoided in hiking boots.

Less Weight, More Cost Over Time
Most trail runners only last for a single season of regular use. The softer rubber on the tread wears down quickly, and the shoes’ lightweight materials typically show significant wear and tear after several months of hiking. In contrast, a good pair of hiking boots—especially boots with a durable all-leather upper—will last for years. Though the upfront cost of hiking boots is higher, the long-term expense is much, much less.