Not at all. The INSCYD test is for all athletes who want to improve: from amateur to elite. The report is designed to be clear and understandable for everyone, with simple explanations and practical advice that you can directly apply to your training.

You don't need to be in top physical condition to take the INSCYD test. However, it's recommended that you've recently resumed some training sessions in your sport, especially if you're coming back from an injury or a long period of inactivity.

If you have any doubts about your health regarding taking the test, you can consult this page which outlines the main risk factors associated with sports and best practices for prevention. If you still have any doubts, don't hesitate to speak directly to your doctor.

It may be wise to perform the test under the supervision of an acquaintance or training partner.

1. Receiving instructions After your payment, you will receive an email with all the instructions to carry out your test at home, with your own equipment.

2. Performing the test and sending the data You perform the tests and send me:

• The training files generated by the tests

• A short form with your body information (weight, height, body fat percentage or measurements to estimate it precisely) and your fitness goals , so I can tailor the recommendations to your needs.

3. Data Analysis I verify that all data is complete and reliable, then I integrate it into the INSCYD platform which:

• Checks the plausibility of the data

• Generates a comprehensive report with clear explanations for each section

4. Summary and personalized recommendations I analyze the report and provide you with concrete and personalized recommendations for:

• Adjust your training according to your physiological profile and your goals

• Optimize your race strategy

• Adapt your nutrition to your metabolism and energy needs.

5. Coaching option You can also book a 45-minute call to debrief the report and get a concrete action plan.

You will receive your full report within 2 to 4 business days after sending your data.

If you choose the option with follow-up call , we will schedule a 45-minute video call together to explain the results in detail.

The INSCYD test can be useful at several key moments in your training :

1. At the beginning of a preparation → to establish your initial physiological profile, identify your strengths and weaknesses, and define precise intensity zones in order to build a 100% personalized training plan.

2. During the season (every 3 to 6 months) → to measure your progress, adjust your training zones and adapt your strategy according to your new physiology.

3. Before an important race → to refine your pace and nutrition strategy .

   • For short races (< 1 h) : the test determines your optimal pace according to your tolerance to lactate/H+ ions.

   • For long events (> 90 min) : it calculates your energy expenditure and the use of your glycogen reserves, in order to avoid any energy failure on the day of the event.

Yes. The INSCYD model is based on more than 30 years of research in exercise physiology and has been validated by numerous independent studies comparing its estimates with direct measurements taken in the laboratory (gas analysis, lactate, muscle biopsies).

🔬 Key scientific validations:

• A study conducted on 31 cyclists demonstrated a near-perfect correlation (r = 0.99) between PMLSS calculated by INSCYD and PMLSS measured in the laboratory, with an average difference of only 4.6 W : 👉 PubMed – INSCYD physiological performance software is valid to calculate PMLSS

• Another independent study showed that the VO₂max and MLSS values estimated by INSCYD differ by less than 0.13 ml·kg⁻¹·min⁻¹ from direct measurements, confirming the reliability of the energy model : 👉 Podlogar et al. (2022) – Utility of INSCYD athletic performance software

• Validation of the Power-Performance Decoder (PPD) protocol — the basis of the INSCYD field test — also showed a strong correlation between the estimates and laboratory measurements : r² = 0.98 for VO₂max and r² = 0.84 for VLamax , even with GPS data only: 👉 INSCYD – Validation and Verification of the Running Power-Performance Decoder (PPD-R)

📊 In summary:

The margins of error observed are generally identical to those observed in laboratories (2 to 4%) when the protocol is properly followed.

This is why the INSCYD test is now used by the best cycling teams , many national federations , and universities around the world.

Conclusion: INSCYD is now recognized as the most accurate field tool outside the laboratory , combining the scientific rigor of a metabolic test and the practicality of a field protocol.

The test provides a comprehensive analysis of your physiology to understand how your body produces and uses energy during exercise:

• VO₂max 🫁 – Maximum Aerobic Capacity. Measures the amount of oxygen your body can use to produce energy. A high VO₂max = better endurance, better recovery, and an excellent correlation with health and longevity.

• VLamax ⚡️ – Maximum anaerobic/glycolytic capacity . Indicates your lactate production and explosiveness. A high VLamax favors short, powerful efforts, while a low VLamax improves endurance and energy efficiency.

• Anaerobic threshold (MLSS) 🧪 – Your critical intensity . This is the maximum intensity you can maintain without accumulating lactate. A key indicator of endurance performance, influenced by the balance between VO₂max and VLamax.

• FatMax 🔥 – Optimal fat burning zone The intensity where you burn the most fat, useful for developing your energy autonomy.

• CarbMax 🍬 – 90g carb/h Intensity : The intensity at which your body consumes 90g of carbohydrates per hour. 👉 This is the intensity most correlated with Ironman performance .

• Carbohydrate stores 💪 Amount of muscle glycogen available to produce power during exercise.

• Personalized training zones 🧭 Paces, power and heart rates according to your physiological profile.

• Performance curve ⏱️ Estimated speed or power you can maintain from 20 seconds to 60 minutes.

➡️ You then receive a personalized analysis and concrete advice from a certified coach to adapt your training and nutrition according to your unique profile and objectives.

Fundamental principle: the two energy systems of endurance

In endurance sports, your body produces energy via two main systems:

1. Glycolytic/anaerobic pathway : produces energy rapidly via glycogen breakdown, with lactate formation — measured by VLamax .

2. Aerobic pathway : uses oxygen in combination with lipids and lactates to produce energy — measured by VO₂max .

⚠️ A single maximum effort cannot distinguish the energy contribution of each energy source. Several efforts of varying durations are needed to "decode" the contribution of each.

INSCYD method: modeling on multiple forces

1. Collection of several short and long efforts

• Typically: 20 s, 3 min, 6 min. Each effort uses the aerobic and anaerobic systems differently, creating a signal that can be used by the model.

2. Data input: power / speed

• The physiological simulator adjusts VO₂max and VLamax to match the observed data.

• The software compares the total energy demand to the share attributable to each energy sector:

  • Total energy = aerobic + glycolytic

  • The anaerobic contribution is subtracted to estimate the remaining aerobic contribution.

• This principle is similar to classical methods of calculating VO₂max via energy adjustment.

3. Iterative optimization process

• The model tests different combinations of VO₂max and VLamax to minimize the gap between real measurements (power or pace) and simulated values.

• This iteration allows us to converge towards extremely accurate estimates of the two key parameters.

4. Derivation of other physiological indicators

• Once VO₂max and VLamax are determined, all other metrics (thresholds, FatMax, carbohydrate consumption, energy efficiency, lactate concentration, MLSS, etc.) are calculated via the metabolic laws of the model.

• For example, MLSS is estimated by combining VO₂max and VLamax over different efforts and comparing the results to laboratory standards.

✅ Result : you get a complete map of your energy metabolism, as precise as a laboratory test, but easily achievable in the field with your usual equipment.

Yes, and that's precisely what makes it so strong.

INSCYD offers the accuracy of a laboratory test , but in your real training conditions , with a complete analysis of your physiology.

• 🧪 Complete laboratory test : this allows, in particular, the measurement of running economy , but this data is only meaningful if it is normalized according to the substrates used (fats vs. carbohydrates) at the tested pace — which is rarely done correctly. Furthermore, these tests are expensive (€200–400) , performed in a Artificial environment (treadmill, home trainer) and the speeds obtained therefore often do not reflect your paces on the road .

• 💉 Lactate test : a simple lactate curve in relation to your intensity provides very little useful information . It doesn't allow you to quantify your aerobic (VO2max) or glycolytic (VLamax) capacity , nor to precisely define your thresholds , due to the lack of a precise and universal detection method (and no, your thresholds aren't exactly at 2 or 4 mmol/L of lactate!). The result: training zones that may be poorly calibrated and little usable information for calibrating your training.

• ⚙️ FTP Test (20 minutes) : This test only accurately estimates your average power output over 20 minutes, without providing any physiological data. It is absolutely not a good test for calculating your anaerobic threshold, as it can range from 85% to 98% of your 20-minute intensity depending on the athlete's profile. Basing your entire training on this approximation risks training you too high or too low , slowing your progress and potentially increasing your risk of injury.

👉 INSCYD combines scientific rigor, practicality in the field and a complete reading of your physiology (VO₂max, VLamax, FatMax, thresholds, substrate oxidation, etc.) — that's why it is today the preferred solution of the biggest sports federations and coaches around the world.

We want you to be completely satisfied with your experience with our physiological test.

• Cancellation before receiving the report: You can cancel your order within 14 days of payment and receive a full refund (no justification required).

• After receiving the report: Once the test report has been delivered, no refund will be possible, even if the 14-day period following payment has not yet expired. The report contains personalized and actionable data, which cannot be "returned."

This policy ensures the quality and exclusivity of the information provided to each client.