100 Miles for 100 Years of Insulin: Data Analysis

“With limited additional energy required (form power) to run at this cadence, and a substantially faster pace, we felt this was the correct decision for him.

Stephen and the COROS Sports Science team had been in discussions the weeks leading into his 100 mile run. Prior to the 100 mile run, we had to collect data. To maximize the use of his COROS POD and provide meaningful insight, some testing was needed. Below are a few key workouts. It should be noted that Stephen is an accomplished runner and has been running competitively for many years. 

Sept 8th 2021 Training Run

Sept 8th Training Run

Key metrics we were focusing on included

  • Cadence
  • Heart Rate
  • Pace
  • Form Power

Our focus was to identify a cadence that produced a low heart rate and low form power for Stephen without sacrificing pace. While pace was going to be slower for 100 miles, we still needed Stephen to finish around 24 hours. 

From this run we noted that Stephen prefers a natural run cadence of 180 steps/minute which allows him to maintain an aerobic endurance heart rate and minimal form power. 

October 5th 2021 Training Run

We wanted to try a slightly different cadence to test Stephen’s efficiency. In order to test this, we had Stephen run short intervals at 170 steps/minute to analyze his heart rate, pace, and form power. 

Oct 5th Training Run

From this run, you can see that as cadence drops to 170, so does pace. Heart rate falls into the high 110’s and form power remains steady around 80-85 watts. 

Two run comparisons

MetricSept 8th RunOct 5th Run
Heart Rate120-130bpm115-118 bpm
Form Power85-90 watts80-85 watts
Comparison of Training Runs

Following multiple conversations and discussing how each run felt, we decided to have Stephen target 180 cadence for the 100 mile run while actively running. While his heart rate was slightly higher, it was still well within his aerobic endurance zone. With limited additional energy required (form power) to run at this cadence, and a substantially faster pace, we felt this was the correct decision for him.

100 Miler

Due to the duration of the event, we knew Stephen would be walking uphills to conserve energy, and running the downhills and flats. His pace would also vary based on stopping for food breaks, bathroom stops, and other necessities. Here is a break down of each marathon. 

Marathon Number One:

Total Time: 5 hours 25 minutes

Avg Pace: 12:24/mile 

Avg Cadence: 149

Avg HR: 121 BPM

Notes: The first marathon saw Stephen put together his best 10 miles of the entire day (1st 10 miles). Not surprisingly, Stephen started out fresh and was able to stick to his original plan. When running, he was holding 175-180 cadence and then walking the uphills and stopping as needed. Stephen was well on pace of finishing within his dedicated 24 hour window. 

Marathon Number Two:

Total Time: 6 hours 30 minutes

Avg Pace: 14:53/mile

Avg Cadence: 143

Avg HR: 116 BPM

Notes: As Stephen went through the second marathon, his pace dropped off substantially. He added a total hour to his time. In doing so, he dropped his average cadence down to 143 and his heart rate down to 116 BPM. Stephen could have improved this marathon by running more, but during a 100 mile run, it’s often more important to focus on nutrition/preservation vs speed. This was a calculated decision to slow down but something that could be improved on going forward. 

Marathon Number Three:

Total Time: 6 hours 8 minutes

Avg Pace: 14:03/mile

Avg Cadence: 145

Avg HR: 114 BPM

Notes: Marathon 3 was interesting for Stephen. It had some of the slowest miles of the day (65-70) and some of the fastest miles of the day (75-80).  This data does a great job of demonstrating the darkness of night (4AM-6AM) vs getting to the race in time to start (8AM-9AM). In the data, you can see a spike in power and pace during this time. Stephen had adrenaline again and the sun was finally peaking over the horizon!

Marathon Number Four:

Total Time: 6 hours 39 minutes

Avg Pace: 15:14/mile

Avg Cadence: 141

Avg HR: 125 BPM

Notes: Stephen was becoming fatigued. He had the highest heart rate of the day during this portion but it was also his slowest. This was his limit of endurance. Any longer and it would have become a walk at best. Stephen was able to pick up the pace the last couple of miles with the end in sight, but the fatigue had already set in. Stephen finished the last marathon with nothing left in the tank!


Looking through the data and times, there is a direct correlation between average cadence and pace. While this is obviously on the surface, it should be noted for future long distance events that Stephen competes in. While walking will always have an important role in ultra marathons, the more time Stephen can focus on running at his efficient cadence (aerobic endurance heart rate) the faster he will finish overall.  If this would have been a race, Stephen could look to return and improve on his time with this new tactic.  Again, nutrition and preservation are key to ultra events, but we now have a fantastic data point to use for future performance!.

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