How Steady Understands Your Fitness

Steady breaks your event down into the physiological dimensions that matter for it, then sets concrete targets for each one.

First, it classifies your event by terrain and duration — a mountain granfondo with steep climbs demands different things than a flat century. Then it weighs five training dimensions based on what your event actually requires:

• Threshold (FTP) — how much power you can sustain
• Aerobic floor (LT1) — your efficient all-day power ceiling
• Durability — can you hold power deep into a long effort
• VO2max — your capacity for hard surges and climbs
• Repeatability — can you respond to repeated attacks or steep kicks

A mountain granfondo weights durability and aerobic floor highest. A flat granfondo weights threshold. A Zwift race weights repeatability and VO2max. The system also adjusts based on what you're trying to do — racing for a podium shifts targets higher than finishing comfortably.

For each dimension, Steady computes a specific numeric target (e.g., "you need an FTP of ~3.2 W/kg for this rolling granfondo at your pace") so every gap is measurable, not vague.

Event goals (granfondos, sportives, centuries) use the full demand pipeline — terrain classification, duration scaling, and objective-based adjustments.

Performance goals work differently. If your goal is "raise my FTP," Steady knows that means sweet spot and threshold work. "Climb faster" means threshold and VO2max. "Win Zwift races" means sweet spot and VO2max plus repeatability. Each performance profile has explicit training priorities rather than deriving them from event characteristics.

Zwift category upgrades have their own demand model with FTP floors and surge targets per category. If you're far from your target category, the plan is heavily threshold-focused. If you're close, it shifts toward repeatability — you have the engine, now you need to use it in races.

Steady pulls your last 90 days of rides and extracts:

• FTP estimate — from your best sustained power efforts at 20, 40, and 60 minutes, cross-referenced for consistency. If 3+ efforts agree within 5%, confidence is high.
• Aerobic threshold (LT1) — from long, steady rides (90+ minutes at even power). Steady looks at how well your heart rate tracked your power output.
• Durability — from your longest rides: does your power fade in the second half? Does your heart rate drift up relative to power?
• Volume and consistency — how many hours per week you've been riding, how regular it is
• Efficiency trend — is your watts-per-heartbeat ratio improving, stable, or declining over time?

Every ride also gets classified (steady effort, structured workout, race, or mixed) so Steady knows what kind of data it's drawing from.

FTP: Steady takes your best power outputs at 20, 40, and 60 minutes and applies standard duration adjustments (a 20-minute effort overstates FTP by roughly 5%). It prefers recent data — if you have enough efforts in the last 30 days, it uses those. Your FTP never drops below your best observed 60-minute power.

When your FTP changes during a block, Steady updates all future workouts automatically. The plan structure stays the same — only the absolute watt targets adjust.

Aerobic threshold (LT1) is harder to estimate but arguably more important for endurance training — it's the power ceiling where you're still burning fat efficiently and can ride for hours.

Steady finds it by filtering your rides to long, steady efforts (90+ minutes, even power) and checking for low heart rate drift. If your HR stays proportional to your power for 90+ minutes, the power you held is a reliable LT1 marker. When this estimate is confident, it directly sets your endurance zone ceiling — which is more accurate than the generic "75% of FTP" that most apps use.