A deep dive into my Frankfurt Marathon data

After each training/race, I like to take time to analyze the data and assess my performance. Here is a closer look at my Frankfurt Marathon data.

Related : Frankfurt Marathon race report

The training

Running distance by week the last 3 months before the marathon

I decided to run Frankfurt Marathon mid September with the race taking place on the 29th of October. I was already in a decent shape but I was clearly lacking running volume.  I had only 6 weeks to get ready. That gives 4 weeks to build up running volume then 2 weeks to taper. 

The coach did his magic , I have done the hard work and, at the end of the 4 weeks of training, I felt in a great shape and was definitely ready for the race. This feeling is confirmed by my performance management chart which shows that 2 weeks before the race, I have reached my highest running CTL (fitness) this year. It is always good to look at the training data and see improvement, it gives a huge confidence boost. With the reduction of volume during the taper, my running CTL dropped by 9% in 2 weeks and my TSB (form) went up from -11 to 9. I keep these values for reference for the next marathons. Considering how the legs felt on race day, running CTL and TSB seemed to be just right.

TrainingPeaks Performance Management Chart - Run

The course

Frankfurt Marathon is a flat and fast course. According to my watch, the total ascent is 68m spread over 42.2 km. The course goes through the city of Frankfurt then heads to the suburbs and comes back to the center.  Honestly, I didn't see much of it. I was totally focused on my running pace, form, hydration and nutrition. I should probably plan a proper city trip to Frankfurt. I ran two marathons there and I only know the start/finish area. :-)

Frankfurt Marathon course

Frankfurt Marathon course profile

The race

My race plan was to run 8 times 5km at 4'25"/km to 4'30"/km then run 2km with what is left in the legs. That would give 5km splits between 22' to 22'30'' and a final time between 3h06 to 3h10. 

This is how it worked: 5 splits at the target pace (1, 2, 6, 7, 9), 3 splits slightly faster (3, 4, 5) and one split slower (8). Overall it was a good pacing even though I would consider running faster than the target pace as a poor pacing. In this case, I just had few seconds faster without forcing anything, I don't think it had any impact on the race so it is not a big deal.

I ran the first half in 1h32'20" and the second half in 1h34'18". That's 1'58" difference, mainly because I walked in the last aid station before the 40th kilometer mark. The wind was also very strong between the 37th and the 40th kilometer. It is not a negative split yet but I am getting close. ;-)

Frankfurt Marathon run splits

Frankfurt Marathon run splits

The next two graphs show how much I improved in marathon running. The first one is the Heart rate by Distance graph from Frankfurt Marathon 2015. It shows my heart rate dropped every 2.5 km to 5 km starting from the 10th kilometer. The reason is that I was slowing down/walking through the aid stations to have a gel and drink some water. This strategy results in wasting of valuable minutes at the aid stations and losing of momentum. 

Frankfurt Marathon 2015 - 3h27 


The second graph is from Frankfurt Marathon 2017. It shows the Heart rate / Cadence by Distance. The obvious difference is that the heart rate was stable for the total duration of the run. I was in a comfortable heart rate zone all the way to the finish. The cadence was steady at around 174 steps per minute. There was a slight drop around the 40th kilometer as I walked through the last aid station. This improvement was achieved thanks to a better hydration and nutrition strategy. I started the race with a small bottle of water that I dropped after 10 km. I didn't have to take anything from the first two aid stations. From the third aid station and going forward, my goal was to quickly take the gel 200m before the aid station then grab a cup of water and drink it. Everything has to be done without dropping the pace. It did work pretty well and I didn't lose any second at the aid stations. I only failed once at the last aid station where I had to walk to drink one coke. I was a bit surprised that just half a cup of water every 2,5 km was enough to stay hydrated the whole race. I was overestimating my water needs in my previous marathons.

Frankfurt Marathon 2017 - 3h06

The Cadence Distribution Chart shows how steady my cadence was through the race. I was in the 170-180 range for more than 97% of the time. That's a pretty good cadence for a marathon. I think I would have to increase it a little bit to have a better shot at the sub 3 hours marathon.

Frankfurt Marathon cadence.PNG
Frankfurt Marathon PaHR.PNG

The Pa:Hr (Aerobic decoupling) is a very interesting metric. It shows the relationship between pace and heart rate over the duration of the activity. The lower the Pa:Hr, the better. Values below 5% show good aerobic fitness. My value for the marathon was 2,32% for the entire run and 1,01% for the last hour. The EF (Efficiency Factor) is another interesting metric. It is calculated by dividing the running speed (NGP) by the average heart rate.  When comparing similar workouts it shows how the aerobic fitness has evolved. The higher the EF, the better. For for Frankfurt Marathon 2015, my EF was 1,36. In 2017, it was 1,51. 


After looking at the training and racing data, I am very satisfied with the outcome of the race. It translates my current fitness level. There is still room for improvement that will hopefully take me to a sub 3 hour marathon. 

Related : Frankfurt Marathon race report