Best Zwift Workouts to Increase FTP (2026): By Rider Type

Q: Do I need to know my VO2max and VLamax to pick workouts?

You don't need to, but it's the difference between targeted training and guessing. The two values tell you whether to raise your ceiling, convert it to threshold, or lower VLamax — three different workout emphases for the same FTP goal.

By Björn Kafka, Performance Coach · Author · WorldTour Coach July 13, 2026

Listen to this article Narrated by Björn Kafka · 7 min · AI voice

You've done them all. The 30/15s, the sweet-spot grinders, the over-unders, the 5×4 VO2max sets. You've got the pain cave, the smart trainer, the fan. And your FTP is within a watt or two of where it sat three months ago.

The problem usually isn't your workout list. It's that "what's the best Zwift workout to raise my FTP?" is the wrong question. The right one is: which workout does your engine actually need — and in what order? Because the session that lifts one rider's FTP is the same session that wastes another rider's month.

Why there's no single "best FTP workout"

FTP — your functional threshold power — is the ceiling on the power you can hold for a long time. But that ceiling is held down by different things in different riders. Raise the wrong one and nothing moves.

Two limiters dominate:

Your aerobic ceiling (VO2max). If your FTP sits at a low fraction of a modest VO2max, you've got room to push the ceiling itself up — and FTP rises underneath it.
Your lactate dynamics (VLamax). A high VLamax — great for sprinting — floods you with lactate at sub-threshold efforts, dragging FTP down relative to your VO2max. For this rider, more hard intervals don't help; lowering VLamax does.

Same goal, opposite prescriptions. That's why a generic top-10 list can't tell you what to do — it doesn't know which lever is holding you back.

The workout toolbox — what each one actually trains

Here's the honest function of the staple Zwift session types, in A Faster You's training zones. The exact targets come from your tested FTP, not a guess.

Sweet Spot (~88–94% of FTP). The efficiency workout: big sustainable-power stimulus for relatively low fatigue. Long blocks (3×12–20 min) build the aerobic durability FTP sits on. Best value for time-limited riders — but on its own it plateaus.
Threshold & Over/Unders (~95–105% of FTP). The most direct FTP work: holding and surging around threshold trains lactate clearance and lifts the number itself. Over/unders (e.g. 2 min just under, 1 min just over) teach you to clear lactate while still working.
VO2max intervals (the V100 zone, ~115–120% of FTP). These raise the ceiling FTP lives under. Short formats — 30/30s (Billat), 30/15s, or 4–5×4 min — accumulate time near maximal oxygen uptake. This is where a stalled FTP usually gets unstuck.
Zone 2 base (~56–75% of FTP). Not glamorous, but it raises mitochondrial density and fat oxidation and lowers VLamax over time — which is exactly the FTP lever for a high-VLamax rider. It's also what lets you absorb the hard sessions.

Every one of these is on Zwift, and you can browse the full library at whatsonzwift.com. The tool isn't the hard part. Choosing and sequencing them is.

Which of these is your FTP workout?

This is the part the lists skip. Match the work to your limiter:

If you're a high-VLamax rider (punchy, strong sprint, FTP feels low for how fast you accelerate): your FTP is capped by lactate, not by your aerobic ceiling. Counter-intuitively, the work that raises your FTP is more Zone 2 volume and sustained threshold work, plus VO2max intervals — not another month of short, sharp efforts that keep VLamax propped up. The sprinter's instinct (do more sprints) is exactly wrong for raising FTP.

If you're a high-VO2max, low-VLamax rider (diesel, big sustained power, no kick) and your FTP still feels capped: you've got headroom to convert ceiling into threshold. Threshold blocks and sweet spot turn your large aerobic engine into a higher sustainable number. More base won't move it much; you already have the base.

If your FTP is simply low across the board: raise the ceiling first. A VO2max block lifts VO2max, and FTP rises underneath it once you convert with threshold work. This is the most common stall — riders grind sweet spot forever and never touch the ceiling that's actually limiting them. Your VO2max is that ceiling; see where yours stands by age before you decide it's not your limiter.

Same dream number, three different to-do lists — and you can't pick yours by reading a list of workouts.

The order matters as much as the workouts

Even with the right workouts, stacking them randomly is why most self-coached FTP builds stall. The sequence is the program.

A Faster You uses metabolic periodization: instead of fixed base→build→peak blocks on a calendar, it sequences your work by where your VO2max, VLamax, and recovery actually sit. Broadly, far from your goal you raise the ceiling (VO2max blocks); closer in you convert it (threshold and sweet spot) into a higher sustainable FTP; throughout, you manage VLamax with base volume. And when a VO2max block is the priority, concentrating those sessions and then recovering hard outproduces sprinkling one VO2max workout into every week — block-organized VO2max training has been shown to outperform even spacing for the same total load in trained cyclists.

Random workout-of-the-day picking gives you a bit of everything and a peak of nothing. The order is what turns sessions into adaptation.

Don't sabotage the hard ones — fuel them

One practical note that quietly decides whether any of this works: VO2max and threshold intervals run almost entirely on carbohydrate. A 60-minute hard session can burn 100–200 g of carbs — that's normal, not excessive. Riders who chronically under-fuel their key sessions watch their FTP stall regardless of how good the plan is. Eat before, sip carbs during the long ones, refuel after. Train the right workout in the right order, fueled — that's the whole formula.

A lever the road can't give you: low-cadence (torque) intervals

Indoor riding has one quirk worth exploiting. A smart trainer carries far less flywheel inertia than the real system of wheel, body, and road speed, so each pedal stroke is a slightly higher-torque event — more so if you climb in a low gear and let the wheel turn slowly. That makes the trainer the ideal place for low-cadence intervals: your VO2max or threshold efforts ridden at 50–70 RPM instead of a free 90+.

It's a real stimulus, not a gimmick. In a 2024 trial, 26 young (17–20) well-trained female cyclists ran an identical polarized interval program — the only difference was cadence. The low-cadence (50–70 RPM) group raised VO2max by 8.7% versus 4.6%, and maximal aerobic power by 8.1% versus 3.0%, at the same training load (Hebisz & Hebisz 2024). Honest caveat: it's a small, specific sample that followed a low-intensity-only phase, so the gap would likely be narrower in riders already used to intensity — but the direction holds, and it raises VO2max, which is the whole point.

One thing it is not: strength training. Even in dedicated torque work the relative force stays under ~54% of maximum dynamic force (Barranco-Gil et al. 2024) — well below what builds maximal strength. Low-cadence intervals work through neuromuscular recruitment and an added aerobic stimulus, not max force. Real strength still lives in the gym.

Where it fits by rider type: use it to add bite to your VO2max or threshold work when you want more ceiling stimulus without more hours. How much you stand to gain depends on your own profile — a Powertest measures the VO2max and VLamax that decide whether more ceiling stimulus is even your lever, so you dose low-cadence to your physiology instead of guessing.

What a profile-driven build actually looks like

Without inventing a rigid template you should copy blindly, the shape of a build that respects your profile is consistent:

Early — raise the ceiling. If a low VO2max is your cap, this is where a concentrated VO2max block (30/30s, 4×4s) does its work, with easy Zone 2 around it to absorb the load.
Middle — manage the limiter. A high-VLamax rider leans into Zone 2 volume and longer sub-threshold work here; a diesel skips straight toward conversion.
Late — convert to FTP. Threshold blocks and over/unders turn the raised ceiling into a higher sustainable number, sharpening toward your goal event.
Throughout — recover on purpose. The adaptation lands on rest days, not interval days.

The watts and durations inside each session come from your tested numbers — which is the whole reason a measured profile beats a copied plan.

Build mine around my numbers →

Stop guessing which workouts you need

You can spend a season testing workouts on yourself, or you can measure the thing that decides which ones work. The Powertest determines your VO2max and VLamax from a standardized effort on your own trainer — no lab, no mask — and tells you which limiter is holding your FTP down. From there, A Faster You builds the workouts and the order into a plan that runs in Zwift, and re-calibrates every time you re-test.

Run a Powertest and start your free trial → — find your limiter, then train the workouts that actually move your number.

One more thing — why your FTP number itself can mislead you

Two riders with the identical FTP can need completely opposite workouts to raise it, because the same FTP can sit on a high-VLamax sprinter's engine or a high-VO2max diesel's. FTP tells you where your threshold is, not why — and "why" is what picks your workouts. That's the same reason a Zwift FTP test isn't the whole story: the number you build your whole training around can't, by itself, tell you how to build it. Measure the engine underneath, then pick the work.

FAQ

What are the best Zwift workouts to increase FTP? The most effective types are threshold and over/under intervals (≈95–105% of FTP, the most direct FTP work), sweet spot blocks (≈88–94%, high value for low fatigue), and VO2max intervals like 30/30s or 4×4s (≈115–120%, to raise the ceiling FTP sits under). Which to prioritise depends on whether your FTP is limited by your VO2max or your VLamax.

How often should I do FTP workouts on Zwift? Two to three quality sessions a week during a build, on top of easy Zone 2 volume, with real recovery between them. More isn't better — FTP only rises when you absorb the work, which is why the sequence and recovery matter as much as the sessions.

Is the 30/15 (or 30/30) workout good for FTP? Yes, for raising the VO2max ceiling that FTP sits under — they accumulate time near maximal oxygen uptake at relatively low fatigue. But if your FTP is limited by a high VLamax rather than a low ceiling, base volume and threshold work move it more than short intervals do.

Sweet spot vs threshold — which raises FTP faster? Threshold work (≈95–105%) lifts FTP most directly; sweet spot (≈88–94%) builds sustainable power for less fatigue and fits time-limited riders, but tends to plateau on its own. Most riders need both, sequenced — sweet spot to build durability, threshold to convert it.

Why has my FTP stopped improving despite hard Zwift workouts? Usually one of three things: you're training the wrong limiter (e.g. grinding sweet spot when your ceiling is the cap), stacking workouts without periodization, or under-fuelling your key sessions. A Powertest identifies which limiter is yours so the workouts target it.

Do I need to know my VO2max and VLamax to pick workouts? You don't need to, but it's the difference between targeted training and guessing. The two values tell you whether to raise your ceiling, convert it to threshold, or lower VLamax — three different workout emphases for the same FTP goal.

Workout intensity zones are expressed as a percentage of your tested FTP; exact targets in an A Faster You plan are computed from your measured VO2max and VLamax via the Mader metabolic model (Mader, 2003; Mader & Heck, 1986), European Journal of Applied Physiology, from a standardized Powertest. Interval-training principles: Billat, V. (2001), Sports Medicine; Rønnestad, B.R. et al. (2014), Scand J Med Sci Sports 24(1):34–42. Low-cadence interval evidence: Hebisz, R. & Hebisz, P. (2024), PLOS ONE 19(11):e0311833 (n=26 well-trained female cyclists aged 17–20); Barranco-Gil, D. et al. (2024), J Sci Med Sport (relative pedaling forces stay under ~54% of maximum dynamic force). Zwift workout library reference: whatsonzwift.com. Guidance describes how workout choice depends on individual physiology; individual results vary.