May 6–7, 2023 · Garmin Edge · 63.5 kg · 10,054m climbing
TSS 1,450 · NP 196W · IF 0.708 · VI 1.289
What this tells you: Your 5-min power of 670W (241% FTP!) shows explosive short-duration capacity on the Slovenian climbs. The 1-hour MMP of 259W (93% FTP) after 36 hours of gravel is exceptional — sustained aerobic output near threshold deep into the race. The 7200s (2h) MMP of 238W shows your aerobic ceiling was fully accessible even in the closing stages.
Where to improve: The Variability Index of 1.289 is the highest of all your races and reflects the true character of gravel racing: repeated power surges on loose climbs, zero-power technical sections, and fast fireroad cruising. While some variability is unavoidable on gravel, targeting 1.20 VI would reduce glycogen burn rate by approximately 8%, a meaningful gain over 36 hours.
Elite-level cardiac response: Negative aerobic decoupling of –4.6% means your heart became more efficient as Seven Serpents progressed — HR fell while power was maintained. The cool Slovenian second night (7°C on the Karst plateau) is the dominant driver, as ambient temperature directly reduces cardiac output needed for thermoregulation. This is a strong physiological result for a 36-hour gravel effort.
Weather impact summary: Slovenia in early May offers near-ideal gravel conditions. The cool second night (dropping to 7°C) is directly visible in HR data as the key driver of the negative decoupling — HR fell while power held. The Karst plateau's exposed sections brought the most challenging wind exposure, while the Istrian coast sections in the afternoon added mild heat load. Thermal management was well handled across both nights.
Terrain efficiency observation: The Seven Serpents course through the Slovenian Karst and Istrian hills features many loose gravel descents where technical skill matters as much as power. Your 8.1h of coasting (zero-power rolling) represents 27.5% of elapsed time — the highest of all your races. Some of this is unavoidable on technical gravel, but smoother line choice on the fireroad sections could convert 30–45 min of braking into low-power pedalling.
Biomechanical read: Power balance on gravel surfaces is inherently more variable than on road — loose terrain forces constant micro-corrections through the hips and core. Despite this, the balance trace across 36 hours shows no acute asymmetric breakdown, confirming no injury compensation. The natural drift toward the dominant leg in the final third is expected and acceptable. Core stability training specifically for off-road riding positions would reduce this drift.
✅ Aerobic decoupling –4.6% — your heart got more efficient across 36 hours of gravel. HR fell from 144 bpm in the first half to 131 bpm in the second, while power dropped only proportionally. The cool Karst plateau night was a physiological gift that your body used perfectly.
✅ MMP 5-min: 670W (241% FTP) — explosive climbing power available and used across the Slovenian hills. Maintaining this level of short-duration output after 20+ hours of racing is a strong indicator of glycogen management — you avoided the deep depletion that kills peak power in ultra events.
✅ 11th overall on challenging gravel — the data shows a disciplined first-half strategy with high power:HR efficiency that paid dividends through the second night. Negative decoupling and preserved sprint capacity at the finish confirm this was a well-paced effort, not a survival ride.
✅ Peak power 1,088W (393% FTP) — maximum neuromuscular capacity preserved through 36 hours. The gravel sprint surges demanded repeated anaerobic efforts and the system delivered throughout. No central fatigue-induced power ceiling was observed.
⚠️ Variability Index 1.289 — the highest of all your races. On gravel some surge-and-recover is unavoidable, but the data shows repeated 400–500W spikes on short climbs that could be smoothed. Targeting VI ≤1.20 would reduce glycogen burn significantly over 36 hours — the difference between bonking at hour 28 and finishing strong.
⚠️ Night power drop –30W — day average 214W vs night 184W (–14%). On technical gravel, lower night speed is partly forced by visibility. But a better lighting setup and more night-specific training would help maintain power through the darkness. Caffeine timing (200mg at h=22, before the deepest circadian trough) is the quickest intervention.
⚠️ 8.1h coasting time (27.5% of elapsed) — the most of any of your races. Some is unavoidable on technical descents, but converting even 20% of coasting to light pedalling (50–80W) on runnable fireroad sections would add meaningful forward speed without glycogen cost.