RABIT Strategy for the Marathon

Why Varying Speed Outperforms Constant Pacing

Limitations of Constant Speed Running

•- Early cardiac drift

•- Premature glycogen depletion before 30 km

•- Increased energy cost

•- Reduced mechanical efficiency (monotonous stride)

Benefits of RABIT Strategy

•- Optimized aerobic/anaerobic alternation

•- Enhanced elastic energy recovery

•- Smarter effort perception

•- Delayed fatigue and marathon wall

Final Recommendations

•- Run a RABIT test 7 days before the marathon

•- Adjust between easy and moderate speed

•- Trust sensations more than fixed pacing

•- Let your stride vary naturally for optimal energy

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•Send us your rabit test and marathon one tcx or .fit files : « Just do it »

send it at veroniquelouisebillat@gmail.com

🧠 Run the Marathon Differently: Why varying your speed is more natural and more effective

By Véronique Billat - Université Paris-Saclay & Billatraining

🚫 Stop at constant speed: running at the same pace is a physiological error

Running a marathon at a constant speed is a counter-natural strategy. It's like trying to breathe at the same rate all the time, regardless of how hard you're working or how tired you are. This monotony of stride leads to:

• 🎢 Unnecessary cardiac overload (the heart races even if the effort remains stable),

• 🔋 An early depletion of glycogen, your running fuel,

• 🤯 A loss of elastic energy (related to muscle stiffness and the natural bounce of the step),

• 🦶 A stride that is more costly in energy because of the lack of variation in cadence and amplitude,

• 😩 And above all, an increase in the perception of effort (RPE) for the same speed.

🌀 The body is hybrid: it oscillates between aerobic and anaerobic

Our research has shown that the human body does not use a single engine to run a marathon. It constantly oscillates between the two pathways:

• The aerobic metabolism, which uses oxygen and is efficient at low intensity,

• The anaerobic metabolism, which takes over to accelerate but depletes reserves faster.

🔁 Varying the speed, within well-calibrated limits, allows these two engines to be synchronized, to preserve resources and remain efficient for longer.

📈 The RABIT strategy: a marathon in waves

The RABIT (Running Advisor Billat Training) method proposes a variation of speed around a base speed, alternating:

• Slightly slower periods (optimal aerobic recruitment),

• Slight but controlled accelerations (anaerobic stimulation and muscle recovery).

This creates an oscillating strategy that:

• 🧠 preserves the brain by delaying the onset of mental fatigue,

• ❤️‍🔥 stabilizes cardiorespiratory responses,

• 🧮 maximizes energy efficiency, thanks to variability,

• 🧱 And pushes back the “marathon wall” (the famous collapse at km 30).

🧪 Scientific evidence: entropy, EEG, and fractal variability

Our team's studies show that:

• An oscillating race generates more useful physiological complexity (high entropy),

• The EEG reveals that the brain adapts its activity more finely in a free strategy than in a fixed pace,

• Experienced runners never use a constant speed, but navigate around an average value with regular microvariations.

🧭 Why calibrating to within 0.5 km/h is useless

On the day of the race, it is impossible to maintain an exact mathematical pace. The temperature, sleep, adrenaline, and other runners influence your rhythm.

➡️ The best strategy is to go with how you feel (between “easy” and “moderate”), as suggested by the RABIT test 7 days before the race.

This test provides a personalized speed variation map, which can then be used freely and intelligently during the race.

✅ To remember

✅ Varying your running = running longer, more efficiently, with less fatigue.

✅ Variability is a physiological asset, not a defect.

✅ A lively stride is more profitable than a robotic pace.

✅ Sensation is more reliable than GPS.

🎁 To go further:

👉 Try our online RABIT simulator, which offers you a personalized strategy based on your easy/moderate/difficult speeds.

👉 Find all the scientific details in our open access articles on [MDPI Sports & IJERPH] and in our webapp [RABIT Strategy App].

Remember: varied running means living life to the full! 🏃‍♀️🌬️🎶

https://asepscience.fr/courir-au-naturel-avec-ceinture-et-bretelles-et-surtout-sans-laisse/