The simple answer is, running on trails adds variety to your training. Running and hiking over uneven terrain produces different physical challenges that improve strength and coordination. Basically, you become a better overall athlete. Not to mention, trail running is usually more scenic. Ever looked up and been in complete awe of the surroundings? It happens on the trails.
Being a “trail runner” doesn’t mean you must hit the trails every day; variety in training is always key. Even if you’re new to running, you can safely change up the surfaces you run on during the week. Before hitting the trails, try alternating running around a grassy park or running on a dirt or gravel road, with running on a paved road. If you’re predominately a treadmill runner, add an outdoor run to the mix. If you’re not new to running but new to trails, start out by exploring shorter and less technical trails, or by hiking the more technical trails before running them. On the other hand, if you’re predominately a trail runner, get in some runs on pavement and the track to focus on proper running mechanics and form, along with speedier running.
This all makes sense when you think of the training benefits. First, running on flatter and softer surfaces like a dirt road or a grassy park puts less impact on your legs which helps with recovery. I do my recovery runs on gentle trails or through a wash the day after a harder workout. This also keeps me from focusing on pace and going too fast on a recovery run. Second, most off-road surfaces are uneven which strengthens stabilizing muscles and improves joint mobility. Think of a more demanding trail run as a strength session (Note, this is the opposite of a recovery day trail run). Third, adjusting your stride to manage variations in terrain reduces the risk of overuse injuries caused by repetitive loading. The more you vary the surface (and focus) of your running, the healthier you’ll stay over the long term.
As I mentioned before, one of the best things about trail running is that you can let go of pace expectations and just focus on staying upright. Adding core stability work to your routine 2-3 times a week helps with this (and running in general). As you grow more stable and confident on uneven surfaces, you can gradually add more trail miles and/or more technical trails to your week, or just relax and enjoy an “easy” trail run for a change of pace.
Sometimes I can even get my kiddos to join me on the trails!