Comparing road running to trail running is like comparing apples to oranges. The beauty of pavement is there’s nothing in your way; on dirt (or leaves, or rocks, or mud), you need to be constantly adjusting your body to whatever nature throws at you. Because of that difference in terrain, of course the physiological demand on your body will be different.
If you’re thinking about transitioning your runs from the road to the trail, here’s what your body (and your mind) should expect.
You’ll Use Different Muscles
No matter what terrain you’re on, you’re always putting one foot in front of the other. But on a flat, smooth road, “it’s all about metronomic efficiency,” says David Roche, a running coach and coauthor of The Happy Runner: Love the Process, Get Faster, Run Longer. “You’re generally repeating the same motion over and over and over again.”
This repetitive movement results in a more even distribution of the biomechanical load, adds Stephanie Howe, Ph.D., a running coach. “Your quads, your hips, your hamstrings, your glutes, your calves—they’re all kind of working in harmony to propel you forward,” she tells Runner’s World.
On a trail, where you’re navigating roots and rocks and ditches with every step, that biomechanical load is much more varied. “You start to get everything from side to side movement, eccentric muscle contractions on downhills, different engagement on steep uphills,” says Roche. “There’s a far greater demand on your hips and your stabiliser muscles.” (Think: glutes and core.) Those are the muscles that connect to the pelvis, plus the little muscles in your ankles and feet. Those stabilisers are especially important, because while primary movers like your quads may be doing the lion’s share of the work, these smaller muscles are what help you stay upright when confronting obstacles or unstable surfaces (hence, why your ankles might be sore after a long trail run!).
Generally, trail running is a much more intense total-body workout than road running, and strength training can really help beef up all the muscles that will help you tackle dirt and vert. Workouts that specifically target strength and stability are going to give you the most bang for your buck, developing your primary movers while challenging those smaller muscles as well.
You’ll Damage Your Body Differently
Of course it’s possible to feel sore after a road run—that repetitive motion and constant turnover can lead to chronic overuse injuries. But a trail run is likely to have a more acute effect, mostly due to one factor: the downhills.
Whether you’re on the road or trail, your quads eccentrically contract (or lengthen) and then rapidly contract (or shorten) to propel you forward. On downhills, which you’re more likely to encounter regularly on a trail, your quad muscles lengthen more than they would on a flat or uphill, putting more tension on the muscle fibers. That eccentric nature of downhill running induces more lower limb muscle damage for up to several days after exercise, a 2020 scientific review published in Sports Medicine found. Not to mention, soreness in those lesser-used stabilizer muscles is the norm for new trail runners. “It’s often underestimated how much that energy cost is if you aren’t used to moving that way,” says Howe.
On the plus side, dirt, gravel, and grass are natural running surfaces that have significantly less impact on your bones and joints than running on concrete or asphalt. “There’s just more room for absorption there,” says Howe. “You don’t just hit them like pavement, they have a little more give, which is gentler on your body.” For example, road runners experience higher loads on the Achilles tendon and less shock absorption compared to trail runners, which can increase the likelihood of injuries, according to a 2020 study published in the journal PM&R.
Your Technique Will Vary A Little
There’s no one-size-fits-all approach to proper running form. Everyone’s individual mechanics differ, but you can optimize that form to boost performance or prevent injury. In road running, the goal is to lock into a pace and maintain your form and technique throughout a run. Out on the trails, you need to be more reactive to what’s ahead of you, says Howe—and “your form is going to change depending on how technical the terrain is, what the surface is, if it’s up or down.”
Uphills and downhills require different mechanical patterns, says Roche. The uphill will force your stride to naturally shorten, and “you want to have a slight forward lean from the ankle, so your center of gravity is slightly forward,” he explains. That’s going to help propel you forward and up.
On the downhill, the tendency is to overstride, which will actually be more damaging to your muscles. Short steps will protect you from that, and “you want to move your feet as rapidly as you can tippy tap them while still maintaining good posture,” says Roche. “That will let you adjust on the fly. The best downhill runners are moving their feet fast enough that any misstep is already corrected for by the next step.”
Your Mental Approach Will Change
One of the nice things about road running is, as long as you know where you’re going, you’re free to zone out and almost go somewhere else in your mind. At the same time, a road or track allows you to really push your limits in terms of pace—even when you’re in an almost meditative headspace.
That’s not the case on the trail. “A trail forces you to be present,” says Howe. “You can’t totally disconnect, because you’ll fall on your face.” That doesn’t mean you can’t get into a flow state on a trail, it’s just the kind of flow state where you’re present and aware of every step you’re taking. “It’s like a mindfulness practice,” says Roche. “Your mind can wander, but you come back to whatever you’re doing over and over again.”
Trails also force you to slow down—in a good way. The best way to stay in the moment on a trail is to ditch your watch, or at least stop paying attention to your splits. “Pace on trails does not matter,” says Howe.
Plan your a trail run based on time, not mileage, and “try looking at it from a bigger perspective, like how long it takes you to do a certain loop or finish a climb in one section,” she says. You may not be checking off certain workout milestones, but you better believe that hard work on the trail will contribute to whatever bigger goal you’re working towards, whether better stamina, a stronger body, or even a new road or trail PB.