On the evening of September 1, 2023, Shen Jiasheng, from China, took 2nd place during the CCC Final in Chamonix, France. Finishing at 10:22:30, Shen conquered the 100km course with an overall elevation gain of 6,100+ meters. Having raced this event twice before (5th in 2019, 4th in 2022), Shen took two more steps up the leaderboard for his 2nd place finish. To celebrate this accomplishment, COROS looks closer at Shen's previous training and his CCC race data!

Watch: COROS APEX 2 Pro Chamonix Edition

Analysis Tool: COROS Training Hub

Training Post Western States

As part of Shen's race season, he also raced the Western States 100 on June 25th. Placing 4th in this elite field, Shen put his training into recovery mode immediately after. A good lesson for athletes to take away from this strategy is that athletes should have peaks and valleys in their training focus, fitness, and overall recovery. Looking at Shen's training calendar immediately following Western States, you can see multiple days off and then seven active recovery days before finally re-introducing some longer days to his training

Shen's Training Hub Calendar showing off days and recovery days.

Along with this 2-week training recovery focus, Shen also put a priority on sleep and diet to allow his body to fully heal. As athletes add more sleep and protein/carbohydrates to their diet, it allows muscles to build back stronger and ensure the body is ready for the next training block. Up next was Shen's prep for CCC!

Preparing for CCC

Training Distance can be viewed within the Training Hub EvoLab Metrics.

During the first two weeks of Shen's build, he averaged 170 kilometers/week. He also was familiarizing himself with the CCC course and building his base to sustain his highest week, which was hit during the week of 7/31. During this week, Shen logged nearly 260 kilometers, which is 15% higher than his max training week during his prep for the Western States. Shen was gearing up for a peak leading into CCC.

Peak week of training.

Shen Jiasheng told us that this training was by design and served a specific purpose. His "physical endurance and mental strength are becoming stronger." He could complete the training more efficiently and safely take on a greater volume and intensity of his overall training. After the intense training week, Shen had a week of recovery and during the weekend, he raced Sierre-Zinal (31 kilometers, 2100 meters cumulative climb). Following Sierre-Zinal, Shen began to add in intervals along with those long endurance days needed to successfully prepare for a 100km race.


Leading up to CCC, Shen dropped his volume to 110 kilometers while reducing his overall intensity two weeks prior. The majority of his runs were 90-150 minute endurance sessions. The final week before race day saw Shen reduce the event further to roughly one hour of active recovery runs to ensure his legs were as fresh as possible leading into race day. When athletes carry this much fitness, it is generally better to do light runs vs. no runs, as your body can become stale and lack power when you take full days off.

Shen's training 1 week prior to CCC.

CCC in 2023

The first 50 kilometers

CCC started at 9 am local time on September 1st. The temperature at the start was about 12 degrees, which was very comfortable for racing.

Shen ran exceptionally fast in the first 50 kilometers, taking roughly 4 hours and 35 minutes to complete this segment. This section of the course features gradual climbs and downhill descents. The main climbs during the first 50km were the first 10 kilometers and between 25-30 kilometers. Shen completed this section with an average pace of 5:30/km, an Effort Pace of 4:06/km, and an average heart rate of 144bpm. Based on Shen's data, he was firmly within his Aerobic Endurance pace, which will allow him to maintain this effort over the course.

Shen's Training Zones.

On the descent to the 50km point, Shen was able to take the lead. In this section, he averaged a 4:10/km pace and maintained his heart rate of 144 bpm. Shen's ability to maintain a strong downhill pace is well known within the ultra-running world and is a strength that he would use throughout the day towards his 2nd-place finish!

After 50K

After 50 kilometers, there were many repeated long climbs and descents on the course, which required plenty of physical fitness. Faced with the increasing temperature and progressive fatigue in the first half, the second half was challenging for all athletes.

The increase in the difficulty of the track did not disrupt Shen's rhythm. He continued to move towards his own goal. The overall time spent on this 50 kilometers was roughly 5 hours and 47 minutes, with an average pace of 6'57''/km and an effort pace of 4'49''/km.

The most difficult sections of the race are between 60-65 km and 70-75 km. Shen's Effort Pace reached 4'45''/km. This is remarkable as Shen is still able to run within 10-20 seconds/km of his initial pace through the first 50km.

Last 10K

Shen was showing signs of being out on course for a long time at this point. With rising temperatures and 90km in his legs, he was still able to push over LA FLEGERE and reach the final downhill into Chamonix

Before the competition, we were able to interview Shen. He set his goal to finish the race in roughly 10 hours and 30 minutes. By following a strategic plan, maximizing his downhill sections, and routinely staying within his proper heart rate/pace zones, Shen was able to achieve his goal and finish in a time of 10:22:30. COROS wants to offer Shen a massive congratulations on an amazing 2023, and performance at CCC that will stay with us all for a long time!