For years, Kilian has managed the immense variables of mountain racing (elevation, weather, and pacing) with a complex system he called, ALGORISME MTNMATH.

This detailed log is where Kilian deconstructs the complex details of mountain racing. Elevation gain, weather patterns, and energy cost are all stripped down to a baseline of truth. It is his personal method for planning his effort at the biggest trail races in the world.

The collaboration between COROS and Kilian has always focused on a single objective: translating the logic of the world’s most calculated athlete into a tool that helps every runner perform better. We’ve taken the same principles Kilian applied at the highest stages and built them into Pace Strategy—an intuitive tool within the COROS app that moves professional-grade race planning from a desktop to your wrist.

Math That Moves With You

While the spreadsheet was the foundation, it took time to upkeep and make new plans for every long run, race, or project in the mountains. Pace Strategy handles the heavy lifting of race planning. It automates the hard science of mountain running that previously took Kilian hours to complete, and years to build, into a simple, high-performance interface.

"I used to spend hours on spreadsheets calculating pace on specific inclinations," Kilian says. "The problem is that spreadsheets are static, but the body and the terrain are constantly changing."

Pace Strategy handles that heavy lifting by automating the science. Instead of manual entries and best guesses, you can upload any route into the COROS app and have the software instantly distribute your effort across the course profile.

The auto-generated plan accounts for the steepness of every climb and descent. It translates every part of the course into a consistent level of output aligned with your current fitness, helping you maintain a sustainable intensity.

Quiet the Ego

The COROS app allows you to fine-tune your strategy down to the individual kilometer. This level of granularity ensures your plan accounts for the specific logistical realities of your route.

• Slide to Adjust: Pick any route in the COROS app and simply slide to your target finish time. The app recalculates your pace across the entire profile in real-time.

• Modify Segment Times: Click "Expand and Edit" to manually override estimated segment times or paces. You can view your estimated arrival time for every waypoint or aid station to ensure your crew knows exactly when to expect you.
• Weather Intel: Environmental friction is often the deciding factor in a race. Pace Strategy pulls local weather data for every specific segment of your route. As your race date approaches, you’ll see if a specific climb will be hit by a heatwave or a cold front, and when the sun sets to plan at what aid station you'll need to leave with your headlamp.

Space to Breathe

Once your strategy is set, it syncs to your watch to act as a digital pacer. This provides objective data when fatigue sets in and your internal "feeling" starts to lie to you.

"The adrenaline of race day can mask the real fatigue," Kilian explains. "Sometimes you feel fresh in the first few hours and the euphoria makes you go at a pace your metabolism won't be able to sustain. Having the Pace Strategy plan is like a rational compass that keeps your ego in check."

Pace Strategy keeps you on-track, in real-time:

1. Waypoint ETA: Know exactly when you’ll hit the next aid station or peak based on your specific plan, and how far away it is.
2. Dial in your pace: View your current pace for the exact section of trail you're on and whether it's faster, slower, or right on your target pace.
3. See where you're at: A simple +/- display tells you exactly how many seconds you are ahead or behind your goal time and your distance left and ascent remaining to the next waypoint or aid station.
4. Aid Station Management: Factor in planned rest time so you know how long you've spent in an aid station, and when it's time to start moving again.

1. Estimated Finish Time: Look and see what your estimated finish time is for the entirety of the course based on how quickly you're moving.

Developing this tool required solving complex biomechanical puzzles. While a fire road climb has a direct mathematical relationship with heart rate, there's no simple formula for how running efficiency shifts across grades from 0% to greater than 30%. We collaborated closely with Kilian to teach our algorithms how each runner's efficiency and fitness level respond to the terrain.

"Reducing the volume of mathematical decisions the brain has to make allows you to redirect that energy to being fully present in the environment," Kilian notes. By moving the calculations done in your head to your watch, you save significant cognitive energy for the things that matter most.

Approaching Mastery

If Kilian had this tool when he was eighteen, he claims his path and progression in fitness would have looked different. Early in his career, he learned through trial and error, often pushing his body to extreme limits just to find where they were.

Pace Strategy allows runners to understand the management of internal load objectively much earlier. It allows you to contrast what you "feel" with the real cost your body is taking on. You can find the perfect line where you push your natural limits without crossing them when you shouldn't.

The "Algorisme" began as a private tool for one of the world's most disciplined mountain athletes. But now, we've translated that elite level of preparation into a practical tool for the rest of us.

Pace Strategy is built to help you plan, adapt, and execute. While designed for the mountains, it is equally effective for road races. You can find more details for road-specific strategies here.

"What I am most excited about is being able to translate all the complexity of training and data directly into a practical guide on my wrist. Having the Pace Strategy will help me to nail that effort in these races to be able to give the maximum of my capacities having less up and downs."