This article was written by Sean Rimmer PT, DPT, OCS and first appeared in the summer 2022 edition of our Trail Times newsletter. Rimmer is an avid trail runner and physical therapist living in Colorado Springs, CO, where he is the owner at Run Potential which focuses on rehab and performance training for runners. Above photo: iancorless.com.
Summertime offers the best few months of the year for trail runners to train or go for an adventure in the mountains. Snows have melted, wildflowers are blooming, and although it is an exciting time to train and explore the high country, the physical nature of mountain trails can be overwhelming to say the least.
Trail runners typically spend less time during the winter and early spring months running in the high mountains due to limited accessibility. They are spending more time running on lower elevation trails, roads, or even the “dreadmill” in an effort to maintain fitness during the off-season. Though these efforts of training are helpful at maintaining cardiovascular and some musculoskeletal conditioning, these lower elevation and “flatter” training don’t prepare our musculoskeletal tissues – including our bones, tendons, muscles, and ligaments – for a sudden increase in elevation change when we hit the mountain trails come summer.
As tough as long ascents are on our cardiovascular and respiratory system, long descents pose a potential risk for musculoskeletal injuries if our tissues lack preparedness. Descending mountain trails induces higher loads to our musculoskeletal system due to the eccentric loading. Think of this as your body’s way of controlling you from collapsing on the downhill. Due to these higher loads and potential bio-mechanical compensation when fatigued, training progressions can be a valuable aid in reducing your risk from sustaining an injury.
There are two main components to training that can reduce the risk of injury while descending mountain trails: Neuro-muscular control or coordination, and musculoskeletal loading tolerance in your legs. Neuro-muscular control is literally how coordinated you are at allowing your muscles to contract and relax at the appropriate times with integrated postural control and alignment. Musculoskeletal loading tolerance refers to the strength or capacity of our tissues to be prepared for the specific demands of running in the mountains.
These systems can be trained through running progressions by addressing the variables of frequency, duration, and intensity to our training. For instance, increasing frequency could mean adding more times per week you are running elevation, while increasing duration could mean increasing the length of time of each run you are ascending and descending terrain. Increasing intensity could mean how much perceived effort or speed you are adding to your run. All of these variables act interdependently, and should be progressed gradually to avoid training error and reduce your risk for injury while your summer training builds.
On the non-running side of training, adding heavy loaded strength and plyometric exercises can help to prepare your musculoskeletal tissues. There are a multitude of exercises, but the primary focus should be on heavy loading and exercises that include energy storage and release. My go-to exercises for heavy strength training are a rear-foot elevated single leg split squat, single leg heel raises, and a barbell lateral toe tap squat. For the plyometric exercises focused on energy storage and release, you cannot go wrong with a double leg or single leg pogo hop with some external load.
For heavy loaded exercises I suggest 3-4 sets of 5-8 reps at about 80% of 1 rep max, performed 1-3x per week off-season vs in-season training. These reps should feel rather heavy; they should be performed slowly with a focus on controlled lowering and returning back to the starting position, with good alignment, and without compensation. Since these loads are relatively heavy, they should help improve resiliency in your legs from the downhill strain on your musculoskeletal tissue.
The rear-foot elevated single leg split squat or “split squat” for short, is a terrific lower body exercise. It’s basically a lunge except your rear foot is elevated (preferably 8 to 12 inches) onto a box or bench which enhances the loading to your forward leg while performing the split squat. Perform this exercise with an upright torso, a slight posterior pelvic tilt, and your knee tracking over your 2nd-3rd toe of the forward foot while lowering into the squat. You can use a barbell on your back, or hold dumbbells in your arms for external loading; but I will say, using dumbbells adds a grip strength benefit and increased safety if balance is an issue. The main reason I suggest this exercise over a traditional squat variation is due to the split nature of the squat with the legs being loaded both in hip flexion and extension.
The single leg heel raise exercise is simple, yet a terrific exercise for the calf complex. The calf complex includes the gastrocnemius, soleus, and achilles tendon which account for controlling forces of 8x-body weight while running. I choose to perform a single leg heel raise with your forward leg elevated onto a box for balance in some hip flexion and the leg doing the work on a slightly elevated surface like a bumper plate with your heel hanging off the plate. Having your heel raise leg on a bumper plate allows your ankle to move through an increased range of motion. This ultimately improves loading into ankle dorsiflexion, or the eccentric lengthening of the calf complex, which is so important for runners. Improving loading tolerance of the calf complex will not only improve strength and control at the ankle, but it can also add stability to the knee as our shin bone moves over our foot.
The final strength exercise which will aid in preparing you for the downhills is the barbell lateral toe tap squat. This exercise can be rather heavy, as it is performed through a small range of motion through the hip, knee, and ankle. I like to think of this exercise as the runner’s squat, as it looks a lot like mid-stance of running where the highest overall loading response takes place. This exercise is completed by starting out with a barbell on your back in a standing position; you then shift your weight onto the stance leg, bend your stance knee ~40 degrees while simultaneously off-loading your other leg by tapping it out to the side. You then repeat this pattern for the entire set with control of your knee tracking over your 2nd-3rd toes and a relatively upright torso.
Running itself is plyometric in nature, yet the loading of running on flatter terrain will be inadequate for the forces of the mountain downhills. This is why I like to add loaded double leg and single leg pogo hops. This should look a lot like jump rope hopping except without the rope, and an external load. I suggest holding a kettlebell at center, around chest height, ranging 10-25 pounds depending on whether you do single leg or double leg hops. You do not need excessively heavy weight with this one, and at times body weight may be adequate. I like to mix it up with the rate of hops or how many hops per minute, and amplitude or height of the hops. Both of these variables should be accounted for and are valuable for preparing our leg’s musculoskeletal tissues. I often perform anywhere from 20-30 second reps for 3-4 sets, 1-3x per week pending the season of training.
When trails and mountains are primed for running, there’s less likelihood for runners to spend their time indoors weight training. Our bodies like progressions, so they can adapt accordingly while reducing risk for injury. Therefore, it’s wise to have a resistance training program focused on heavy loading and plyometric exercises during the off-season and more of a maintenance program during peak training time. I suggest 1-2x a week during the summer months, or every other week during higher volume of run training. The last thing you want is an early summer running injury that takes you away from the beautiful mountain trails and the best season of running.