Nearly every runner probing the outer limits of their genetic potential has a story to tell about the “Trial of Miles.”
The Trial of Miles is that mythical time when runners learn the truth behind this famous quote about running development from John L. Parker’s Once A Runner: “The only true way [to maximize your running potential] is to marshal the ferocity of your ambition over the course of many days, weeks, months, and (if you could finally come to accept it) years.”
As the hero in that story learns, the secret is simple—it’s the “process of removing, molecule by molecule, the very tough rubber that comprised the bottoms of his training shoes.”
In other words, in running and in life, less is rarely more. Reaching big, scary goals usually requires more focus, more passion and more work.
My personal introduction to the Trial of Miles happened during the summer of 2012, when I was interning at a non-profit in Boulder, Colorado, with just a few cents to my name. Every Wednesday, the local market had a big sale—avocados five for $1, sweet potatoes just a few cents, peanut butter by the pound and olive oil by the barrel. I turned a few bucks into tens of thousands of calories, and those calories got turned into miles.
Each day, I ran 60 to 90 minutes in the morning and afternoon, sometimes fast but never structured, with no GPS watch or complicated training methodology. I started out running around 60 miles per week in May, and by the end of August I was running over 100. At the tail end of summer, racing with my pinky toes showing through holes in my shoes, I won the Trail 10K National Championship.
Moral of the story: If you can strategically increase your training volume while staying healthy and motivated, you can experience breakthroughs you might never have thought possible.
At the pro level, runners like Jim Walmsley and Chris Mocko credit their monumental success to increases in training. But the principles behind the Trial of Miles can work wonders for any level of athlete, whether you are starting at 10 miles per week or 100 miles per week.
Increasing volume strategically works because it improves running economy, aerobic development and just about every other biomechanical, neuromuscular and cardiovascular variable that goes into making a strong runner. However, it’s not for everyone. Make sure you are generally healthy, with at least a couple of years of consistent running under your belt and a long-term commitment to seeing what you are made of. If you are over 50 or have had stress injuries in the past, be especially carefully with any increases in training volume.
When you start the Trial, think of yourself like a caterpillar subject to Chaos Theory. Based on the initial conditions of your physiology and background, you have no idea how long you will need to spend in your cocoon, and there are no guarantees of what type of butterfly will emerge. But there is only one way to find out.
So how can you design your own Trial of Miles? Here are five rules.
1. Develop a weekly goal mileage or total time running.
The Trial of Miles doesn’t rely on specific daily workouts, but on the accumulation of training volume over time. Start with a weekly goal around your current training level, and then increase progressively as you adapt and the training load feels less stressful.
There are no magic numbers to aim for, but once you reach a certain level (around 70 miles per week for men and 50 miles per week for women, with variation depending on background), do your research and talk to knowledgeable runners or coaches about how much you can handle healthily. Take one full rest day each week, and every three weeks take one down week where you decrease volume by 15-to-30 percent (unless directed otherwise by a coach).
2. Run mostly easy, but allow yourself to finish some runs faster when you feel frisky.
Hard workouts are important components of a well-rounded training plan, but it’s essential not to overload the body with stress. Therefore, while increasing volume during the Trial of Miles, structured workouts can take a back seat to just making sure you get the runs in.
Because it’s difficult to predict when you will feel great and when you will feel crappy, start every run easy—at an aerobic and conversational effort. As you build into the run, you can progress a bit, to where you can still say a few words but not a full paragraph. And on the rare day when you feel like a mystical super-unicorn sent to prance over the trails, you can end the last third of the run even faster.
For advanced athletes, add strides in the second half of a few runs each week when you feel good, to work on running economy. These athletes might also benefit from workouts during The Trial, but be careful not to overdo it.
3. Run two times in a day occasionally if you have time.
As your volume climbs, it’s more difficult mentally and physically to get all of your running done at once. So use the time you have—run in the morning, then again at lunch or after work. Even better: run commute to work in the morning and evening.
Many professional runners throughout history have run twice a day for many reasons, including somewhat controversial ones like optimizing natural hormone production. But stripped down to their essence, double runs allow you to add more stress without the injury risk that consistent longer runs entail.
4. Eat plenty.
Every day in the Trial of Miles (and training generally) involves minor amounts of breakdown. When you are recovering from your runs, your body is healing those imperceptible injuries and adapting to that stress. To heal and adapt properly, you need energy availability, or calories beyond the bare minimum necessary to complete its normal functions. So keep the calories flowing!
In general, athletes thrive off of diets high in good fats to fuel the aerobic engine, with plenty of protein to rebuild muscle and enough carbs to provide energy. But don’t let the quest for a perfect diet be the enemy of a good diet. When in doubt, feed the machine more so the machine can roar.
5. Think long-term health above all else.
The Trial of Miles—and running for performance generally—can be risky. If you feel an injury brewing, even if it seems minor, take time off. If you feel over-stressed, try something new. And, by gosh, if your running is not contributing to long-term contentedness, recalibrate your goals.
Be especially aware of warning signs of overtraining like chronically tired legs, reduced libido or abnormal shifts in mood. Undertaking the Trial of Miles is doing to your body what a blacksmith does when crafting a sword: you are playing with fire, and you could get burned. But if you do it right, crafting your body carefully over time, the result might be something sharp, tough and almost unbreakable for training battles to come.
David Roche runs for HOKA One One and NATHAN, and works with runners of all abilities through his coaching service, Some Work, All Play.