Sports
Cycling Interval Workload Calculator
Calculate hard minutes, between-interval recovery, full session time, target and recovery kilojoules, average interval-block power, FTP share, and work-to-recovery ratio.
Total target-power time-
Recovery blocks-
Total recovery time-
Complete session duration-
Mechanical work in hard intervals-
Mechanical work in recoveries-
Mechanical work in interval block-
Average interval-block power-
Target power as FTP-
Work-to-recovery time ratio-
Decision view
Power-step interval profile and accumulated work
Power-step interval profile and accumulated workWork and recovery rectangles update with interval count, durations, watts, FTP threshold, and cumulative kilojoules.
Exact scenario comparisonTarget work power (W) changes while all other entered assumptions remain constant.
| Target work power (W) | Total target-power time | Recovery blocks | Total recovery time | Complete session duration | Mechanical work in hard intervals | Mechanical work in recoveries | Mechanical work in interval block | Average interval-block power | Target power as FTP | Work-to-recovery time ratio |
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How to use Cycling Interval Workload Calculator
- Enter a target power that can be held across every work interval.
- Use the actual rolling recovery power rather than treating recovery as zero.
- Add warm-up and cool-down separately from the scored interval block.
Calculator guide
Understanding Cycling Interval Workload Calculator
Cycling intervals combine power and time. Counting only minutes hides the mechanical work performed, while counting every recovery after the final repetition overstates the scheduled block.
Detailed calculation process
Detailed cycling interval time, power, and work calculation
The default session uses six four-minute efforts at 280 W with five three-minute recoveries at 120 W.
General formula: T_w=n*t_wn_r=max(0,n-1)T_r=n_r*t_rT_s=T_w+T_r+T_{wu}+T_{cd}W_w=P_w*T_w*60/1000W_r=P_r*T_r*60/1000P_b=1000*(W_w+W_r)/(60*(T_w+T_r))I=P_w/FTP Watt-seconds are joules; dividing by 1,000 gives kilojoules. Average block power includes rolling recovery but excludes warm-up and cool-down with no entered wattage.
What each symbol means
Worked substitution with the default inputs
The default interval block contains 511.2 kJ at 218.46 W average, within a 64-minute complete session.
Worked situations
Practical examples
- Six four-minute intervals create 24 target-power minutes.
- Five three-minute recoveries separate those six efforts; no extra recovery is added after the last effort.
Better inputs
Useful tips
- Use lap data to replace planned watts with observed average power after the session.
- Keep FTP source and test protocol consistent across comparisons.
- Reduce target or repetitions when form, cadence, or health signals deteriorate.
Before relying on the result
Limitations and common mistakes
- Mechanical work is not metabolic energy expenditure.
- The page does not calculate normalized power, Training Stress Score, or physiological response.
- Terrain, inertia, cadence, cooling, nutrition, fatigue, and power-meter error are excluded.
Reference
Key terms
- Mechanical work
- Power multiplied by time, expressed here in kilojoules.
- FTP share
- Target interval power divided by entered functional threshold power.
- Interval-block power
- Average watts across hard efforts and their between-effort recoveries.
Important note
This is workload arithmetic, not a training or medical prescription. Stop exercise and seek appropriate help for concerning symptoms.
Frequently asked questions
Why is warm-up work excluded from kilojoules?
No warm-up or cool-down wattage is entered, so only the interval block is integrated.
Is 112% of FTP appropriate?
The calculator reports the ratio but does not prescribe safe or effective intensity.
Can recovery power exceed target power?
The math allows it, but the inputs would no longer describe a conventional recovery interval.