The way we improve as trail runners is by building our endurance. And the way to build endurance is by running high mileage while still being able to recover between each run. If we push high mileage too far or sacrifice recovery we increase our risk of illness or injury.
The way to run really high, injury-free mileage, is to use a long-term strategy, building mileage annually rather than weekly. Know your personal mileage limit and allow a recovery week after running near your limit. Use strength training and cross-training to build fitness away from running.
Let’s take a closer look at how we can massively increase our training volume and stay injury free.
How To Run High Mileage On Trails Without Injury
When I was in high school, running cross-country during the winter and middle distance on the track during summer my average weekly mileage never got above between 20 and 30 miles per week. In the summertime, during track workouts, weekly mileage would hit about 20 miles a week because we were doing more speed work. During the winter cross country when it was more of an endurance type of training, mileage would increase to around 30 miles a week at the peak.
At the same time, I was part of the cycling team in high school and would routinely do about 200 miles a week on the bike, which helped to give me a really good base level of endurance. This allowed me to be able to compete with runners that were doing far higher mileage than I was, thanks to the crosstraining benefits of going out training with the cycling team.
So, from that point of view, if you want to increase your training volume relatively quickly without getting yourself injured, consider doing the bulk of your endurance training as crosstraining. This can be either on the bike like I did or maybe doing aqua jogging in the pool as well. Anything that allows you to work your cardiovascular system without the direct impact of running will have a benefit.
Think Of High Mileage As A Long Term Strategy
The way to be able to increase your mileage safely and run the high mileage safely is by looking at the increase in your mileage as a long-term strategy. For instance, when I was in high school during cross country and track over a 5-year period my weekly mileage would be in the region of about 20 miles per week at first and then gradually towards the end of my high school career, we were up at about 30 miles per week. For the first 3 years after high school I kept that mileage at between 20 and 30 miles per week without any problem.
I hit my first big issue when I try to ramp that weekly mileage up to 50 miles a week within a single year and, to my surprise, picked up an injury. So look at your mileage and increases as a long-term project and not something that you can do within a single year or for that matter a couple of months.
Know Your Personal Limit
Knowing your personal limit is something that is vitally important when it comes to increasing your trail mileage. However, this is easier to say than actually do because the only way you will know that you have reached your personal limit is when you exceed that limit and find that you’re not able to push very much more distance at all without starting to pick up some sort of slight strain or injury.
For a long time, I found that when it comes to actually running out on the trails my body is able to cope with anything up to about 70 miles per week if I push much beyond that I start picking up Achilles issues, a slight knee injury, or things like that. But, what I can do when I get really close to my personal limit is I can drastically ramp up the number of hours that I spend on the bike and get the fitness benefit without the additional pounding on my legs.
Cross Training
As I’ve already alluded to in a couple of the sections above, I find that crosstraining has been massively beneficial to me as a way of increasing my overall training volume while at the same time keeping the amount of pounding that my legs take to a relative minimum.
One of the facts from my crosstraining that I found massively benefits my running is teaching myself how to run on tired legs. And the technique for this is something that I learned during my years of doing triathlon. What I do is I go out on a really hard bike ride of about 90 minutes to 2 hours when I get back from the bike ride I immediately pull on my running shoes and head out for a 30-minute run.
Even though I’m only doing the mileage of a 30-minute run, I’m running on legs that are already fatigued and on an energy system where I’ve already depleted my muscle glycogen. This means that I can have the effect of a 2-hour run or longer but only the physical impact on my legs of 30 minutes.
Strength Training
When it comes to increasing mileage, running long mileage, and staying healthy, strength training is absolutely vital. We must remember that the activity of running is a catabolic activity meaning that it breaks down muscle fibers. Whereas doing strength training in the gym is an antibiotic activity that builds the muscle in your legs.
We are able to stay healthier as runners for longer by incorporating a good amount of strength training into our weekly program. In case you’re worried that strength training in the gym will give you really bulky legs, you can relax. When we are running longer mileage we are running enough for us not to get bulky muscles at all. That is because any of the anabolic effects of doing weight training will be mitigated by the catabolic effect of our long runs out on the trails.
Increasing Annual Mileage
Many relatively new trail runners that I speak to tend to think about increasing mileage by 10% week on week. This can easily lead to them increasing their mileage by more than what they are physically capable of doing, especially when they start hitting higher mileage.
A better way of looking at mileage increases will be to look at it as an overall annualized figure. This helps to account for those weeks where you take a recovery week after a big race in order to prevent an injury. The last thing that you want to do is ramp up your mileage in the week following a marathon or ultra.
The same goes for tapering during the week before a big race. Increasing your mileage by 10% during a taper week will not help you perform well on race day.
Looking at your mileage progression in annual terms helps you to feel better about taking a recovery week and reducing mileage for a single week simply rather than feeling pressurized to increase your mileage when your body actually needs more rest.