Elsey Whyman-Davis, a British trail runner and NHS Doctor, took a stellar win in Nice on Sunday, taking the top spot at the Nice Côte d’Azur by UTMB 100km Race.

Bouncing back from her withdrawal at the UTMB finals due to health complications the month before, the victory was a meaningful one. Crossing the line after 13 hours of racing, she bagged herself a Golden Ticket for the Western States Endurance Race 2024.

We've analyzed how the race unfolded for the Brit and how her training has gone throughout the entire 2023 season. With COROS to support her, she's certainly learned a lot about her body, recovery and next steps for her training and we're unpicking the data throughout her build-up to help you make the right call when it matters most.

The 2023 Trail-Running Season

The Base Fitness score of Elsey throughout the 2023 season.

Over the past six months, we can see that Elsey has been steadily improving her Base Fitness score to an impressive 203 at its absolute peak. Base Fitness is the average of your 42-day training load that helps athletes monitor their fitness over time. We can see from the above picture that she increased her Base Fitness throughout the trail racing season. This meant that as the season progressed, so did Elsey's fitness levels. It is common for your Base Fitness to either decline or maintain throughout a racing season due to tapers going into races. Elsey picked her races well, consistently building in the lead-up to her main goals of the season. The biggest dip in her Base Fitness score is due to a taper ahead of the World Mountain Running Championships and Marathon du Mont Blanc, which were in quick succession.

Training Build to CCC

The UTMB World Finals was the aim for Elsey throughout the 2023 season. Even with a strong period of specific training; clocking 551+ miles in running; accumulating a total Training Load of 12,365; and her strong 2nd place finish at the Eiger Ultra Trail leading into the race, it wasn’t meant to be and Elsey was forced to pull out of the race due to health complications. It can be tough for athletes to make big calls like this in the heat of competition. Still, Elsey is an experienced trail runner, with incredible resiliency and strength, which shows in how she reflected upon the race later.“You can prepare perfectly but things can happen out of your control and it’s important to make peace with it and move on.” This is exactly what Elsey did getting back into training after some recovery and cross-training.

Bouncing Back After CCC

A lesson to take from Elsey’s decision in CCC was that listening to your head over the heart is the smarter decision. This allowed her to get straight back into her specific training less than 10 days later. On Elsey's first day back, she completed a 25-mile training run along the Cornish Coast, where she accumulated a Training Load of 581. Upon analysing this through the COROS Training Hub App (phone) or the Training Hub Platform (desktop) she was able to make the call to return to racing and have one last focused event of 2023. Her target was Nice and proceeded to familiarise herself with the route ahead of the competition. Elsey took herself down to the Côte d’Azur and using the Trail Running Workout from our August Firmware update, was able to complete a 5 x 10-minute specific session up the climb of Col Madeleine. We'll see in a minute just how specific this was to Elsey's race plan. (Click to view Elsey's post on Instagram)

First 20 Miles of the Race

The first 20 miles of Elsey's run.

Cote d’Azur 100km is a tough race. The conditions this year were a mild 17°C (63°F) with a light breeze. Elsey started the race strong averaging an Effort Pace of 08’21” min/mile up the first two climbs. Throughout this section, Elsey gained 6631 feet in elevation gain and topped the highest point on the course.

For these first 20 miles, we also see that Elsey maintains an average Heart Rate of 163 bpm. This was tracked through the COROS HR Monitor, which she wore throughout the race. She was running between her Aerobic Power and Threshold HR Zones for most of this first section. Ultimately, this led to Elsey maintaining the pressure over the field and allowed her to build out a lead.

The Long Descent off the Col Madeleine

Elsey's heart rate throughout the race.

The next portion of the race was a 14-mile technical descent. Elsey was clearly pushing hard in the first phase of this race, a tactical race decision which would later prove effective. However, with such a bold race strategy so early into a 100km race, there is a risk of pushing too hard. With the recent memories of CCC as motivation, over half of the race and elevation gain to come, Elsey had made her decisive move and it was now about maintaining the lead. We begin to see on this descent a gradual decline in her Heart Rate. This continues as a trend throughout the remainder of the race, but with the lead having been built, the focus could switch to mastering the technical aspects of the course and keeping her energy levels high through nutrition.

Rolling Through the Middle Climbs

Elevation profile of the Nice Côte d’Azur 100km Race, with the climbs highlighted.

On the remaining climbs up to Mont Férion, Baisse de Bordinas and Plateau Justice, Elsey could maintain her effort due to a decisive first half. Even as the fatigue built from the 6+ hours of racing, she took these climbs consistently, averaging an Effort Pace between 10’20” min/mile to 10’39” min/mile. Despite movement from behind her in the pack, Elsey was very much in her zone and upon cresting Plateau Justice had a 7-mile descent before the final 3 miles into town along the Côte d’Azur.

The Final 20 Miles of the Race

The final 20 miles of Elsey's run.

As we analysed the opening 20 miles of the race, where Elsey made her big move, the final 20 miles were a stark contrast. Comparing the two distances, Elsey had lowered her average Heart Rate by around 23bpm from 163bpm for the opening 20 miles, down to just 137bpm for the final 20 miles. Her experience and effective race strategy gave her a more controlled run into the finish line.  


In the build-up to the 2023 season and throughout the races, Elsey has consistently shown her determination, tactical ingenuity and superb execution to string together incredible results. As you head into the preparation for your next race, we advise you to consistently analyse the data from your COROS watch through our Training Hub software. As we have done here, you can see trends in previous performances and watch your fitness build over time, helping you make informed decisions on your training to achieve the best results.

If you would also like to have your data analyzed, reach out to our COROS Coaches at coach@coros.com and get the discussion about your data going!