NEW - Weekly & Season Report Update — Energy System Progression (ESPE)
A new analysis component has been added to the training report: Energy System Progression (ESPE).
ESPE evaluates how your power-duration curve has changed over time by comparing two equal training windows. Instead of looking only at total load or recent sessions, it examines how different physiological systems are evolving across the power curve.
What it analyses
The system tracks performance changes at key durations that represent different energy systems:
- 5 seconds — neuromuscular / anaerobic power
- 1 minute — VO₂ capacity
- 5 minutes — high-intensity aerobic power
- 20 minutes — threshold power
- 60 minutes — endurance durability
By comparing these anchors across time windows, ESPE determines:
- Which systems are improving, stable, or declining
- Whether your power curve is shifting toward endurance or anaerobic capacity
- How balanced your overall energy system development is
What you will see in the report
The weekly report may now include:
- Energy system status (anaerobic, VO₂, threshold, endurance)
- Curve dynamics showing how your power curve is shifting
- Adaptation state describing the current training effect (for example: aerobic consolidation or threshold development)
- Derived metrics related to durability, reserve capacity, and system balance
These indicators help explain why your performance profile is changing, not just whether training load is increasing.
What this means for athletes
ESPE does not replace traditional metrics like CTL, ATL, or TSS. Instead, it adds a physiological layer that interprets how training is shaping your performance capabilities.
In practical terms, it helps answer questions such as:
- Is endurance improving faster than high-intensity power?
- Is VO₂ capacity maintaining or declining during base periods?
- Is the power curve becoming more durable across longer efforts?
This information will be used progressively to support more precise training interpretation and future recommendations.
This is phase 2 of the Performance Intelligence upgrade and is the first part (v1) of ESPE
This works for RIDE and RUN (where power is used).
After you run a weekly/season report… Ask for a full ESPE analysis and you will get:
Energy System Progression — Full ESPE (Cycling)
Window: 85 d vs previous 85 d comparison
Curve Source: FFT power-duration curves
Model Quality: Good (R² = 0.84)
This section shows the full Energy System Progression Engine (ESPE) output describing how each physiological system has changed over the last training block.
Power Duration Changes
| Duration | Change |
|---|---|
| 5 s | −19.4 % |
| 1 min | −4.7 % |
| 5 min | −2.0 % |
| 20 min | +2.0 % |
| 60 min | +5.1 % |
Interpretation
- Short explosive power (5s) has declined noticeably.
- VO₂ power (≈5 min) is slightly reduced.
- Sustained aerobic power (20–60 min) has improved significantly.
This is a classic endurance adaptation profile.
Curve Dynamics
| Metric | Value | Meaning |
|---|---|---|
| Vertical Shift | +0.11 | Slight overall power increase |
| Rotation Index | −6.88 | Curve rotated toward endurance |
| Dominant Shift | Aerobic rotation | Power gains favor long durations |
Interpretation
The curve rotation indicates the training block primarily improved durability and sustained aerobic power rather than explosive output.
System Status
| Energy System | Status | Trend Meaning |
|---|---|---|
| Anaerobic | Decline | Less explosive / sprint work |
| VO₂ System | Decline | Reduced high-intensity stimulus |
| Threshold | Moderate Gain | FTP-range development |
| Aerobic Durability | Strong Gain | Improved fatigue resistance |
Adaptation State: Aerobic consolidation
Adaptation Bias: Threshold dominant
Derived System Metrics
| Metric | Value | Interpretation |
|---|---|---|
| Glycolytic Bias Ratio | 1.52 | Moderate anaerobic bias relative to threshold |
| Aerobic Durability Ratio | 0.82 | Good endurance durability |
| Durability Gradient | 0.94 | Sustained power stable over long durations |
| System Balance Score | 0.84 | Balanced multi-system development |
| VO₂ Reserve Ratio | 1.20 | Healthy headroom above CP |
| PDR (5-min reserve) | 58 W | VO₂ capacity above threshold |
Critical Power Model
| Metric | Value |
|---|---|
| CP | 294 W |
| FTP | 300 W |
| W′ | 15.6 kJ |
| Pmax | 689 W |
Interpretation:
- Critical Power and FTP remain closely aligned.
- W′ reserve remains healthy for repeated supra-threshold work.
ESPE Adaptation Summary
The current training phase shows a clear endurance-focused adaptation pattern:
- Aerobic durability and long-duration power are improving strongly.
- Threshold capacity is progressing moderately.
- VO₂ and anaerobic systems are temporarily down-regulated due to lower stimulus.
This profile typically appears during aerobic consolidation blocks, where training prioritizes:
- long steady endurance
- threshold work
- fatigue resistance
Bottom line:
Your physiology is currently shifting toward an endurance-specialist power curve, with improved fatigue resistance and long-duration output.