Race
pacing strategy
Your CP and W′ define what’s possible. Pacing decides what you actually get. Compare four strategies side-by-side, watch W′ drain in real time, and see exactly why going out too hard costs more than it gains.
Quick answer
Your W′ is a finite battery above CP. Every second above CP drains it; below CP it slowly recovers. P(T) = CP + W′/T gives even-split power. Deviations from even power always cost total time (cubic drag law), but some patterns cost less than others. Race Smart — slight fast start, settle, strong finish — typically costs only 1–3 seconds vs even split while being psychologically sustainable.
Race Pacing Strategy
Compare four pacing strategies side-by-side. See exactly how W′ depletes and what each pattern costs in total time.
| Segment | Power | Pace /500m | Time | W′ Remaining |
|---|---|---|---|---|
| 0–500m | 314 W | 1:43.7 | 1:43.7 | 75% |
| 500–1000m | 314 W | 1:43.7 | 1:43.7 | 50% |
| 1000–1500m | 314 W | 1:43.7 | 1:43.7 | 25% |
| 1500–2000m | 314 W | 1:43.7 | 1:43.7 | 0% |
| Average | 314 W | 1:43.7 | 6:54.8 |
Even Split produces identical to the theoretical optimum. W′ fully depletes at segment 4 of 4, forcing the remaining 0 segments to drop to CP (296 W). That's 0% of the race at reduced power — the classic "blow-up" that costs real time.
Frequently asked questions
Why does uneven pacing always cost time?
The Concept2 drag equation is cubic: pace = (2.80/watts)^(1/3). Because of this convexity, the time lost rowing 10 watts below average is always greater than the time saved rowing 10 watts above average. It is the same reason speeding up on one half of a road trip does not fully compensate for going slowly on the other half. Mathematically, Jensen's inequality guarantees that constant power minimises total time for a given energy budget.
What happens when W′ hits zero?
When your W′ battery is fully depleted, you can no longer sustain power above CP. The model drops your power to CP for the remaining segments. In real racing this feels like "hitting the wall" — your legs fill with lactate, stroke rate drops, and split times blow out. The Fly & Die strategy demonstrates this vividly: the fast start drains W′ early, forcing a long painful slog at CP for the back half.
Why is "Race Smart" only slightly slower than even split?
The Race Smart pattern (fast first segment, settle slightly below average, strong finish) deviates only 3–5% from even power in each segment. The cubic cost of these small deviations is minimal — typically 1–3 seconds over 2K. But the psychological benefits are significant: the fast start gets you ahead of competitors, the settle lets you find rhythm, and the knowledge of a planned sprint gives purpose to the final segment. World-record 2K performances almost universally follow this pattern.
Does pacing matter less for longer distances?
Yes. For events longer than ~8–10 minutes, your W′ is fully depleted in the first few minutes regardless of strategy, and you spend the vast majority of the race at or near CP. Pacing strategy shifts from W′ management to sustainable power management — the goal becomes maintaining consistent output and avoiding early over-exertion that causes excessive physiological stress. For 10K+ events, even pacing dominates and deviations are costly because there is no sprint reserve left.
Where does this model come from?
The W′ balance model was developed by Skiba et al. (2012, 2014) and builds on the Critical Power framework (Monod & Scherrer 1965, Morton 2006). The core idea: W′ is a depletable reserve above CP. When power exceeds CP, W′ drains at a rate proportional to the excess; below CP, it reconstitutes with an exponential time constant. This calculator uses the simplified depletion model (no reconstitution during a maximal race) which is appropriate for events up to ~30 minutes where the athlete is continuously above or at CP.