How to Improve Your FTP

FTP — functional threshold power, the highest power you can hold in a quasi-steady state for roughly an hour — is the number nearly all structured indoor training is built from. Raising it is a slower and more boring process than most riders expect, and almost nobody fails at it for lack of effort. They fail for one of three reasons: the intensities are wrong, the recovery is wrong, or they do not complete the sessions. This page deals with all three. If you do not have a number yet, start with how to do an FTP test.

The published zones, and what each one is for

Training zones are expressed as a percentage of your FTP, which is why the figure has to be reasonably current before any of this means anything. The model below is TrainerRoad's published zone breakdown, used here because it is stated explicitly rather than inferred.

Why sweet spot does most of the lifting

Sweet spot sits at 88 to 94% of FTP — the top of tempo running into the bottom of threshold. TrainerRoad's case for it is specific and worth quoting in substance: it drives many of the same adaptations as threshold work — a higher FTP, better muscular endurance, a stronger aerobic engine — at a fatigue cost you can come back to several times a week.

That last clause is the whole argument. Threshold intervals at 100% of FTP are more physiologically pointed, but they cost more to recover from, so you get fewer of them per month. Sweet spot buys more total time in a productive intensity band across a block, and total time in band is what drives the adaptation. The same source is clear that this is not a licence to do more: more is not automatically better, and the right dose depends on your schedule, your recovery and where you are in the season.

On interval length, TrainerRoad's coaches describe starting riders who are new to structure at around 10 to 12 minutes, moving them to 20 fairly quickly, and prescribing 20 to 30 minute intervals for sweet-spot work, progressing both interval length and total time in zone over a block. That progression — same intensity, more minutes — is the mechanism. Not more watts.

Where threshold and VO2 max work fit

Threshold work (95 to 105%) is the most direct attack on the number itself. It is also the work that most benefits from ERG mode, because holding exactly 100% of FTP for 20 minutes by feel is genuinely difficult and drifting 5% low turns a threshold interval into a sweet-spot one.

VO2 max work (106 to 120%) raises the ceiling above FTP rather than FTP itself, which eventually pulls FTP up behind it. It is the most demanding work on the table, it is where riders most often over-reach, and it belongs in a focused block rather than sprinkled through every week.

Endurance riding (55 to 75%) is not filler. It is where aerobic base and durability come from, and a rider whose entire week is intervals has an FTP that holds for 20 minutes and collapses at hour three. Most of your volume should live here.

What to look for in a setup that lets you train this way

A power number from one device, consistently. Everything above is a percentage of FTP, so if your FTP came off a trainer and your intervals are paced from a different power source, the percentages are fiction. Pick one reference device for the block. How accurate are power meters explains why two honest devices never match and why consistency beats absolute accuracy here.

ERG mode, or the discipline to do without it. ERG holds the target wattage regardless of your gear, which turns a 25-minute sweet-spot interval from a concentration exercise into a pedalling exercise. If your trainer does not have it, you need a very disciplined eye on the number. ERG mode explained covers the detail, including when to turn it off.

Cooling. This is the most underrated item on the page. Indoors there is no airflow, core temperature climbs through a long interval, and the body down-regulates the effort before the legs are finished. A proper blower fan is the cheapest thing that improves the quality of your hard sessions.

Something that tells you about recovery. Heart rate is the cheap answer. A session where power is normal but heart rate is well above its usual value for that intensity is a session to cut short.

A position you can hold for an hour. Sweet-spot intervals are long, and riders abandon them for saddle discomfort as often as for legs. That is a bike fit question, not a training question.

The short answer

What actually helps you finish the sessions

#	Product	Best for	Score	Price
1	Wahoo Kickr Core 2 The trainer that makes structured training easy: ERG holds the watts so the only thing you have to do is keep pedalling.	Best trainer for holding an interval target	9.0★★★★★9.0 out of 10	$549.99 · View on Amazon #ad We may earn a commission · Price as of October 5, 2026
2	Favero Assioma Duo If your season has an outdoor half, measure both halves with the same device — otherwise your FTP means two different things.	Best power source if you also train outdoors	9.3★★★★★9.3 out of 10	$539.97 · View on Amazon #ad We may earn a commission · Price as of October 5, 2026
3	Polar H10 Power says what you did; heart rate says what it cost. The second one is how you avoid training yourself into a hole.	Best for managing the recovery side	9.3★★★★★9.3 out of 10	$104.49 · View on Amazon #ad We may earn a commission · Price as of October 5, 2026
4	Lasko U15617 The least glamorous item on this page and the one most likely to let you finish the session that raises your FTP.	Best fan — heat is the real limiter on long threshold work	9.0★★★★★9.0 out of 10	$93.99 · View on Amazon #ad We may earn a commission · Price as of October 5, 2026

How long before the number moves?

Longer than a week and shorter than a season. The honest framing is that FTP responds to a block of consistent work — several weeks of the same kind of training, progressing interval length and total time in zone — and that a single good session tells you nothing. Retest at the end of a block, not on a day you happen to feel strong, because an FTP measured on a good day sets every subsequent interval target slightly too high and quietly makes the next block harder than it should be.

Two practical rules follow. First, do not retest more often than every few weeks; the test itself costs a session and the measurement noise is larger than the real change over a short window. Second, if you are using a platform that estimates FTP from your ride data rather than from a test, let it do that rather than testing constantly — Zwift vs TrainerRoad covers how the two platforms differ on this.

The mistakes that stall an FTP block

Riding every session hard. The most common error by a wide margin. If your easy rides are at 80% of FTP, they are tempo, and you are not recovering between the sessions that matter. Endurance riding should feel easy enough to be slightly boring.

An FTP that is too high. If your tested figure was optimistic, every prescribed interval is above its intended zone, you fail sessions, and you conclude you are not fit. Re-test honestly, and prefer a figure you can actually hold.

Chasing wattage inside the interval. Progression means more minutes at the same percentage, not more watts at the same duration. The watts rise when the FTP rises.

Treating heat as a fitness problem. If you consistently fade in the second interval of a session, try a fan before you change the training plan.

Comparing your number to other people's. FTP is only comparable between riders when the measurement devices and protocols match, and they almost never do. How accurate are power meters explains why a few percent between devices is normal, which is enough to make most comparisons meaningless.

Where cadence fits

Cadence is not a lever for raising FTP directly, but it changes what a given wattage costs you muscularly, and a lot of riders default to a cadence that makes long sweet-spot intervals harder than they need to be. What cadence should you ride at goes through what the research actually says, including the uncomfortable finding that the most metabolically efficient cadence is far lower than the one most people ride.