What is a good W′ value?

W′ is individual — typically 15,000–30,000 joules (15–30 kJ) for trained cyclists, with punchy, explosive riders tending higher. What matters more than the raw number is how you spend it during an effort.

How does W′ balance recover?

It recharges whenever you ride below your Critical Power — the further below, the faster — but full recovery from a deep effort takes minutes, not seconds, which is why repeated attacks get progressively harder.

Is W′ balance the same as FTP?

No. FTP (or Critical Power) is the sustainable power line; W′ is the finite reserve above it. W′ balance tracks how much of that reserve is left in real time.

Do I need a power meter to use W′ balance?

Yes — W′ balance is power-based, so it needs power data. Stride then models your Critical Power and W′ and computes the balance for every ride automatically.

Training Guides·Updated 23 Jun 2026

How to Read W′ Balance During a Ride

W′ balance (W-prime balance) is a real-time estimate of the anaerobic energy you have left above your Critical Power — your 'matches'. It starts full, drains when you ride above Critical Power, and recharges when you drop below it. Reading it lets you spend hard efforts wisely and avoid blowing up. Stride computes W′ balance second-by-second for every ride.

Quick answer

W′ balance = your remaining anaerobic battery. It empties above Critical Power and refills below it. Keep some in reserve for the decisive climb or sprint, and only run it to zero near the finish.

What is W′ balance?#

Your Critical Power is the power you can hold almost indefinitely; W′ (W-prime) is the fixed amount of work you can do above it before exhaustion. W′ balance tracks how much of that reserve remains at any moment. For the background, see what is W′ prime and why Critical Power beats FTP.

How to read it during a ride or race#

Watch your W′ balance fall every time you go hard — an attack, a steep ramp, a bridge to a group — and watch it recover when you ease below Critical Power on a descent or in the bunch. The skill is budgeting: don't let it hit zero early, because once it's empty you can't respond, and refilling it takes real time below Critical Power. Save enough for the decisive moment and only empty it as you approach the line.

Why it beats a single number#

An FTP or average-power figure tells you nothing about when, within a ride, you ran out of matches. W′ balance does — it turns a hard, punchy ride into a story of when you spent your reserve and whether you paced it well, which is exactly what you need for criteriums, hilly road races and surging group rides.

W′ balance in Stride#

Stride fits your Critical Power and W′ from your power history and plots W′ balance per second across every ride, and uses it to detect sprints and matches automatically. You can see exactly where you went into the red and how long it took to recover. Try Stride free.

FAQ#

Frequently asked questions

What is a good W′ value?: W′ is individual — typically 15,000–30,000 joules (15–30 kJ) for trained cyclists, with punchy, explosive riders tending higher. What matters more than the raw number is how you spend it during an effort.
How does W′ balance recover?: It recharges whenever you ride below your Critical Power — the further below, the faster — but full recovery from a deep effort takes minutes, not seconds, which is why repeated attacks get progressively harder.
Is W′ balance the same as FTP?: No. FTP (or Critical Power) is the sustainable power line; W′ is the finite reserve above it. W′ balance tracks how much of that reserve is left in real time.
Do I need a power meter to use W′ balance?: Yes — W′ balance is power-based, so it needs power data. Stride then models your Critical Power and W′ and computes the balance for every ride automatically.

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