INSCYD'er and short distance runner Vanessa Scaunet during the European Championships Indoor, Torun 2021.

More and more running coaches use INSCYD to create better training programs and race pacing for their athletes. This blog covers the story of Vanessa Scaunet, who was able to switch her running goal from a 2k cross country to an 800m track race, within 10 days.

Cross country runner Vanessa Scaunet became an INSCYD’er when she performed an outdoor field-test in cooperation with the RUNNING AND MORE lab.

“Because of the test I can now prepare for the upcoming seasons and finetune my trainings to reach my goals!” – Vanessa Scaunet


At that time of her test, Vanessa was preparing for the National Championship cross country short distance: 2000 meters, a distance that is covered in around 7 minutes.

The power demand of such a race is approximately 5.7 W/kg or 2160 Joule/kg. The energy contribution however, differs per person. With Vanessa having a high VO2max and a medium VLamax, approximately 87% of the energy is covered by her aerobic metabolism and only 13% is covered by her anaerobic energy.

Because Vanessa had her metabolic profile in INSCYD, she and her coach where aware of how she produced the needed energy for a 2000m race and knew what her limitations are. For a race of almost 7min, an increase in VO2max would allow her to run faster. On the other hand, the (anaerobic) glycolytic power of the VLamax was already sufficient for a 7 minute race.

To increase VO2max and maintain VLamax, her coach chose specific interval training. Creating highly individual interval training is easy using the INSCYD lactate- and recovery graph. More about that in this blog.

“With INSCYD we were able to optimize her interval training because we knew the exact work-recovery ratio.” – Ivo Roelandt, trainer of Scaunet


While Scaunet was preparing for a 2000 meter cross country, she received a phone call at the end of February, saying she was qualified for the European Championships indoor: 800 meters. A distance that is covered in just around 2 minutes.

The question arose: does it make sense to accept such an unexpected invitation 10 days before an event that is 3.5 times shorter in time length than what you are preparing for? Of course, Scaunet accepted the invitation to the European Athletics Indoor Championships — who wouldn’t?!  She not only accepted it because it is an honor to participate, but she knew she was able to race at a highly competitively level, thanks to the INSCYD test. How?

Predict running race performance

Luckily, Vanessa and her coach used the Performance Projection to get a better understanding of the race demands at the European Championships. The Performance Projection (see video below) allows a coach to simulate any race distance and any speed, based on the real metabolic profile of an athlete.


To cover the 800m in around two minutes, her power output or total energy demand would be approximately 127% of what she was used to in the 2000m race.

Such a high power output equals an oxygen demand of about 83 ml/min/kg. However, Vanessa’s VO2max is in the mid 60s range.

The metabolic demand (oxygen demand) increases when running speed increases. The actual oxygen uptake depends on how well the aerobic energy system is developed. The difference between metabolic demand and energy production via the aerobic system is covered by the anerobic energy system.

“INSCYD shows how the aerobic system and the anaerobic [glycolytic] system interact, like no other standard test does.” – Ivo Roelandt, trainer of Scaunet

This means, almost 20 ml/min/kg of oxygen demand cannot be covered by her aerobic metabolism. Therefore, this needs to be covered by anaerobic – mostly glycolytic – energy. As a result, the aerobic energy contribution is decreased to approximately 72% (instead of 87% during the 2000m), while the anaerobic energy contribution is increased to approximately 28% (instead of 13% during the 2000m).


Knowing the new race demands was interesting, however Vanessa and her coach only knew those demands 10 days before the race. It was too late to change the training program, but predicting the future race performance offered great insight for future training! Let’s have a look.

The INSCYD lactate recovery and accumulation graph shows how fast lactate accumulates at any intensity. Knowing Vanessa’s profile, she is able to reach a maximal lactate concentration of approximately 13-14 mmol/L when fully exhausted. When dividing the maximal lactate concentration by the duration of the race, we know the maximal lactate accumulation rate.

For example, the cross-country race that Scaunet was preparing for at first would take about 7 minutes. With a maximal lactate concentration of 14 mmol/L, the maximal lactate accumulation rate may not exceed 2 mmol/L per minute (14 ÷ 7 = 2). Otherwise, she would hit the maximal lactate tolerance before the finish line.

The lactate recovery- and accumulation graph below, shows that the running speed (x-axis) at a lactate accumulation rate of 2 mmol/l/min (y-axis) is approximately 5.4 m/s.

Knowing this speed enables coaches to create a pacing strategy for a race and helps them predict (running) race performance.

The Lack of Pyruvate & Lactate accumulation graph shows how fast your athlete accumulates lactate (fatigue) at any given intensity. The lactate accumulation depends on the lactate production in the Glycolytic system (VLamax), lactate combustion in the Aerobic system (VO2max) and body composition

However, Vanessa now had to prepare for a 2 minute race. In our example, this would allow for a lactate accumulation rate of 7 mmol/L per minute (14 ÷ 2 = 7). By looking at the pace that matches this lactate accumulation rate, Scaunet’s trainer was immediately able to see whether this was a competitive pace. And it was…

This can be seen on the lactate curves that are created, using the performance projection in INSCYD. This shows a lactate curve for the 2000m and the 800m, using Vanessa’s already existing metabolic profile derived from her first INSCYD test. Using this graph, it is now pretty simply to read her speed at her maximum lactate concentration….

The lactate graph shows the lactate concentration (y-axis) at the finish, depending on running speed (x-axis) and distance.

Further improvements

The performance projection allows her coach to “play around” with her metrics as well. Instead of only projecting her performance for a yet unknown race, it is also possible to edit one or several of the metrics of her metabolic profile. He can then find out how much time she saves with a higher VO2max, how gaining or losing 1kg of body mass affects her race results, or what the maximum lactate concentration would be if she increases her VLamax by doing more anaerobic training.

All this can be answered BEFORE prescribing a training program or signing up for the next Championships.

European Athletics Indoor Championships – Torun 2021

Vanessa Scaunet survived the qualifications and made it to the semi-finals. She finished in 18th position at Europeans. We want to congratulate Vanessa Scaunet on her performance and thank the performance lab and her coach for sharing this story.

Want to know how you can better train and coach your running athletes, using INSCYD? Schedule a free personal demo now!