English Endurance
Cycling Fitness Profiler
Build a power profile from three durations — a fifteen-second peak, a five-minute peak, and a twenty-minute peak. The tool derives threshold power, places each duration against Coggan's population standards, and works outward into training zones, fuelling rates, pacing targets, and session prescriptions.
Rider and peak power data
Fitness profile
Relative performance strengths
Power profile against population standards
Rider type indication
Performance levels. Untrained → Fair → Moderate → Good → Very Good → Excellent → Exceptional → World Class. Bands come from Dr Andrew Coggan's power profiling standards for competitive cyclists, using the — table. The bar position is an interpolated placing within the band, not a measured percentile.
Power training zones
| Zone | Focus | Power range | Purpose |
|---|
Heart rate training zones
Fat burning and metabolic capacity
Fat max zone — 62.5 ± 9.8% of VO₂ max
| Optimal fat burning power range | — |
| Fat oxidation rate range | — |
| Carbohydrate oxidation range at fat max | — |
Metabolic flexibility range
| Fat burning power range | — |
| Estimated crossover point | — |
Research base. Achten & Jeukendrup (2003) reported maximal fat oxidation rates of 0.52 ± 0.15 g·min⁻¹, reached at 62.5 ± 9.8% of VO₂ max. Individual variation is substantial; laboratory testing remains the only precise route.
Personalised carbohydrate fuelling
| Intensity band | Relative intensity | Carbohydrate | Energy rate |
|---|---|---|---|
| Zone 1–2 · recovery and aerobic | <75% FTP | — g/hr | — kcal/hr |
| Zone 3–4 · tempo and threshold | 75–105% FTP | — g/hr | — kcal/hr |
| Zone 5+ · VO₂ max and anaerobic | >105% FTP | — g/hr | — kcal/hr |
Notes. Carbohydrate requirements are derived from energy expenditure and the respiratory exchange ratio typical of each band, then capped at practical absorption limits — 40, 90 and 120 g/hr respectively. Lower intensities allow greater fat oxidation and so reduce carbohydrate need.
Ultra-endurance pacing guidelines
Terrain and conditions
- Sustained climbs. Add 5–10% to the target. Gravity fixes the pace, and the small surplus is repaid on the descent that follows.
- Strong headwinds. Add 3–8%. Holding the target power into a headwind costs disproportionate time, so a modest lift is usually worth it.
- Everything else. Ride the lower half of the range early. Ultra-distance results are decided by how little the power decays in the final third, not by the average of the first hour.
Structured training sessions
Fat max development
- 15 min warm-up at 50–60% FTP
- 3 × 20 min at —, 5 min easy between
- 15 min cool-down at 50% FTP
Focus: maximise fat oxidation capacity and metabolic efficiency.
Aerobic endurance
- 20 min warm-up, progressive into zone 2
- 2 × 30 min at —, 10 min easy between
- 15 min cool-down
Focus: build the aerobic base and mitochondrial density.
Threshold development
- 20 min warm-up, progressive into zone 3
- 4 × 12 min at —, 3 min easy between
- 15 min cool-down
Focus: raise the lactate threshold and sustainable power.
VO₂ max development
- 20 min warm-up including 3 × 30 s at zone 4
- 5 × 4 min at —, 4 min easy between
- 15 min cool-down
Focus: oxygen uptake, cardiac output, aerobic power.
Anaerobic capacity
- 25 min warm-up including 3 × 10 s sprints
- 6 × 30 s at —, 4 min easy between
- 15 min cool-down
Focus: lactate tolerance, anaerobic power, glycolytic capacity.
Training notes. Progress a session by extending duration before raising intensity. Allow 48–72 hours between hard sessions, and concentrate on one or two systems within a block rather than touching everything each week.
How the figures are derived
- Functional threshold power. 95% of the 20-minute peak. A field estimate, not a measurement — riders with strong anaerobic capacity tend to sit below it, and diesel riders above.
- Estimated VO₂ max. 16.6 + (8.87 × five-minute W/kg), Coggan's regression from five-minute power to aerobic capacity.
- FTP as a percentage of VO₂ max. FTP divided by five-minute power, with five-minute power standing in for power at VO₂ max. High values indicate a well-developed aerobic ceiling relative to maximal aerobic power.
- Functional reserve capacity (W′). The difference between five-minute power and FTP, held for 300 seconds and expressed in kilojoules. A simplification of the critical power model, sufficient for ranking riders against themselves over time.
- Performance levels. Coggan's power profiling bands, applied separately by sex to 15-second, five-minute and FTP watts per kilogram. The bar shows placing within the band by linear interpolation.
- Power zones. Percentages of FTP: recovery to 55%, aerobic 56–75%, tempo 76–90%, threshold 91–105%, VO₂ max 106–120%, anaerobic from 121% to 110% of five-minute power, and neuromuscular above that to the 15-second peak.
- Heart rate zones. Anchored on the 20-minute average heart rate treated as lactate threshold heart rate: recovery to 80%, aerobic 81–89%, tempo 90–93%, threshold 94–99%, and VO₂ max and above from 100 to 110%.
- Energy conversion. 3.7 kcal per hour per watt, which corresponds to roughly 22–25% gross mechanical efficiency.
- Fat max window. VO₂ max power is approximated as 1.15 × FTP, and the fat max window taken as 52.7–72.3% of that figure. Carbohydrate oxidation at fat max is the remainder once fat oxidation is subtracted from total energy expenditure.
- Crossover point. 75% of the estimated VO₂ max power — the intensity beyond which carbohydrate supplies most of the energy.
Reading the profile. The three durations describe different systems, and a rider is rarely equally placed on all of them. The gap between them matters more than any single figure: a wide spread between 15-second and threshold power points to a sprinter who has not yet built an aerobic base, while a narrow spread at a high level describes a time trialist. Treat the fuelling and pacing figures as starting points to be adjusted against how sessions actually feel, and re-test the three durations before assuming the profile still holds.