A road bike bolted to a turbo trainer in a domestic garage before dawn, lit by a single work lamp hanging from the rafters.

The trainer holds the watts. You hold on.

Pick one of 42 structured sessions and CrankPilot drives your smart trainer through it in ERG mode, target by target. There is no world to ride through and nobody to race. Just the interval, and whether you can stay on it.

42 workouts, from recovery to VO2max

Endurance, sweet spot, threshold and sprint work, three FTP tests, or a .zwo file you brought from somewhere else. Every target is a percentage of your FTP, so the same session scales as you get fitter. It never asks how you're feeling.

Interval profile · work laid down over time and watts

0.2 kJ

4.2 kJWork in one cell — one minute by eight watts. Six steps, one hue. Under 0.2 kJ a cell stays dark.

Sweet Spot Pyramid — 6-8-10-8-6 minutes at 88% of FTP, drawn from the workout file before you clip in. One of the 42.One cell is one minute by eight watts. Its brightness is the kilojoules the file puts in that cell, so a five-minute ramp — the same work spread across a moving wattage — comes out dim and diagonal, and a held block comes out as one hard bright band. The power axis shows the band 64 to 256 W rather than starting at zero, the way a spectrogram shows a band of frequencies. Nothing here is measured from a baseline and nothing lit is cut off: the quietest thing in the session is 100 W.

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Sweet Spot Pyramid, read off the workout file
Block	Minutes	Target	Starts at
Warm-up ramp	5	100 to 220 W	0 min
Work 1 of 5	6	220 W	5 min
Recovery 1	3	125 W	11 min
Work 2 of 5	8	220 W	14 min
Recovery 2	3	125 W	22 min
Work 3 of 5	10	220 W	25 min
Recovery 3	3	125 W	35 min
Work 4 of 5	8	220 W	38 min
Recovery 4	3	125 W	46 min
Work 5 of 5	6	220 W	49 min
Cool-down	5	100 W	55 min

A rider's hands on the drops, gloves on, the lamp burning behind the handlebars.

ERG mode: the trainer holds the watts

Each block has a power target and the trainer changes its own resistance to sit on it, whatever your cadence does. Down 5% if today is not the day, without breaking the interval.

Target, mid-interval

−5%100%+5%

Power: 161 W
Cadence: 85 rpm
Heart rate: 136 bpm

Read off the trainer and your heart-rate strap. Nothing is estimated from wheel speed.

The lamp and the roller door behind it, haze hanging in the beam.

The numbers are done before you unclip

Normalized power 178, intensity factor 0.71, and where the hour actually went by zone. Your power curve runs from one second to two hours, and training load stacks up week over week. It is all computed on the phone the second you stop, so there is nothing to upload and no sync to sit through.

Normalized power: 178 W
Intensity factor: 0.71
TSS: 1
Calories: 10 kcal

Zone split · one cell is one percent of the hour

Z1 12% · Z2 54% · Z3 32% · Z4 1%.One cell is one percent of the hour — 36 seconds — so threshold is exactly one cell, neither inflated to be labelable nor clipped. A band that thin breaks the column's edge instead of trying to be a block. The four published figures are whole percentages and add up to 99, so the column stops one cell short of its 100% rule. That gap is rounding, not missing time, and it is left visible rather than divided up.

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Zone split of the hour · published figures are whole percent and sum to 99
Zone	Share	Minutes	Seconds
Z1 recovery	12%	7.2	432
Z2 endurance	54%	32.4	1944
Z3 tempo	32%	19.2	1152
Z4 threshold	1%	0.6	36
Rounding	1%	—	—

Power curve · one second to two hours

far under

at the ceilingDistance below the best you can hold. The top of the light is the curve.

Your best effort held for every duration, from a standing-start second to a two-hour ride. Everything under the ceiling is lit and brightens toward it, so there is no stroke on the curve at all — the boundary is where the field runs out.The shape, not a result. Nobody's watts are plotted here — the axis is a share of the one-second peak. Yours gets drawn from your own rides.

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Power curve · shape of the view, as a share of the one-second peak
Duration	Share of peak
1 second	100%
2 seconds	96%
5 seconds	86%
10 seconds	74%
30 seconds	52%
1 minute	41%
2 minutes	35%
5 minutes	29%
10 minutes	26%
20 minutes	24%
30 minutes	23%
1 hour	22%
2 hours	20%

Training load · fitness, fatigue, form

58 fitness · CTL at week 12
54 fatigue · ATL at week 12

Fitness and fatigue as two channels of one field, in load per day. Each channel is a crest of light rather than a column standing on the axis: the top of the light is the value. Form — the gap between them — drifts underneath as a ribbon on its own axis, cool above the line where you are fresh and warm below it where you are carrying the week, on the same two hues for the same two reasons.Also the shape, not a result. These twelve weeks belong to no rider. CrankPilot works CTL, ATL and TSB out of the rides you actually do.

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Training load · shape of the view, twelve weeks, load per day
Week	Fitness CTL	Fatigue ATL	Form TSB
Week 1	32	38	−6
Week 2	34	30	+4
Week 3	37	45	−8
Week 4	40	52	−12
Week 5	42	41	+1
Week 6	45	58	−13
Week 7	44	36	+8
Week 8	47	55	−8
Week 9	50	62	−12
Week 10	52	48	+4
Week 11	55	66	−11
Week 12	58	54	+4

Nobody else is in here

No virtual worlds
No group rides
No racing
No leaderboard

Ride Zwift if you want company on the bike, because it is genuinely good at that. This is the other kind of indoor riding.

The hardware still comes with you. CrankPilot pairs the Zwift Ride controller like any other sensor: on a free ride the shift buttons run twelve virtual gears built off your FTP, and inside a workout the paddles push the ERG target up or down mid-interval, so your hands never leave the bars. Outside Zwift's own app, very little else reads it at all.

What it costs

$9.99 a month, $69.99 for the year, first month free. Zwift is $19.99 a month and Wahoo SYSTM $17.99, checked July 2026. There is no account to make and no server of ours holding your rides — each one is yours as a .fit file.

Subscriptions, checked July 2026
App	Monthly	Yearly
CrankPilot	$9.99	$69.99
Zwift	$19.99	$199.99
Wahoo SYSTM	$17.99	$179.99

$69.99 for the year works out at $5.83 a month.