AdaptCycling
The self-coached cyclist

TrainingPeaks vs Intervals.icu: what each one is actually for

Start here: Intervals.icu is the deeper analytics platform and its core is free, while TrainingPeaks is the better place to work with a coach. That settles it for most riders. The complication is that neither one writes your plan or rebuilds it when the week falls apart — TrainingPeaks expects a coach to do that job, and Intervals.icu expects you to. Deciding between them is really deciding which of those two jobs you are hiring for.

By Jim Camut · Former pro & ex-Bruyneel Academy racer

Updated Sep 1, 20264 chapters6 citations

01 / 04

They are not competing on the axis you think

Both draw fitness and fatigue curves, which makes them look like rivals. They are not. TrainingPeaks is a coach-delivery platform with excellent analytics attached; Intervals.icu is an analytics workbench with planning tools attached. Almost every bad purchase here comes from comparing the charts instead of the jobs.

TrainingPeaks Premium runs $19.95 a month or $134.99 a year [TrainingPeaks 2026], and the Performance Management Chart is the reason most people know the name. It is a direct consumer implementation of the Banister fitness-fatigue model: performance as a fitness term minus a fatigue term, each decaying on its own time constant [Morton et al. 1990]. Layered on top is Training Stress Score — duration times intensity squared, scaled to your FTP — feeding the chronic and acute load curves [Mujika 2017]. But the product around that chart is a workspace shared with a coach: the calendar they write into, the structured files that push targets to your head unit, the plan Marketplace. TrainingPeaks has been part of Garmin since the acquisition announced in July 2026.

Intervals.icu comes at it from the opposite direction. The core platform is free, with an optional Supporter tier at $4 a month that adds weather analysis, the annual training plan builder, and early access to betas [Intervals.icu 2026]. On raw analytical depth it is not merely competitive, it is ahead: eFTP, several power-curve models, more than 140 custom metrics you can define yourself, an open API, and integrations with 250-odd services. It covers cycling, running, swimming, and triathlon with separate zones per sport.

One practical decoder note for anyone reading both at once. The Performance Management Chart vocabulary — CTL, ATL, TSB, TSS — is TrainingPeaks terminology, so Intervals.icu names the same underlying quantities Fitness, Fatigue, and Form. The curves are computed from the same modeling lineage; it is the labels that differ, not the methods. Riders regularly assume the two platforms disagree about their fitness when they are looking at the same math under different names.

02 / 04

What the $19.95 actually buys, given the free one is deeper

The uncomfortable comparison for TrainingPeaks is that a free tool models fitness at least as well and customizes far better. What the subscription buys is not superior charts. It is the coach ecosystem, the device-integration breadth, the Marketplace, and the shared professional vocabulary of the sport.

Take the analytics head-on, since it is the axis most people compare. For a rider who wants custom metrics, a power curve they can interrogate several ways, or their own data out through an API, Intervals.icu wins outright and costs nothing [Intervals.icu 2026]. Multi-sport is a genuine second win: if you run in winter or train for a triathlon, separate zones per sport in one place is worth real money, and here it is free. A third is openness — the API means your training history is never hostage to a subscription lapse.

TrainingPeaks earns its price on a different set of things, and they are not trivial. It is the rail the paid-coaching industry runs on, so if a coach is delivering your training, they are almost certainly delivering it here and the subscription is the cost of the shared workspace. Its device integrations are the broadest in endurance sport. The Marketplace is a real inventory of purchasable structured plans. And the PMC vocabulary is the language coaches, podcasts, and training books actually speak — learning it has transfer value beyond the app.

One concrete limitation worth knowing before you buy. The TrainingPeaks Workout Builder is web-only; the mobile app cannot create or edit structured workouts. If your habit is to reshape Thursday from your phone on Wednesday night, that is a laptop trip every time.

03 / 04

The job neither one does

Both platforms will show you that your load ramp is too steep. Neither will redesign next week to fix it. TrainingPeaks leaves prescription to a human coach by design. Intervals.icu hands you a calendar, a workout builder, and a phase structure, then leaves the dragging to you.

This is a property of the metrics, not a gap in the software. Mujika's review of load quantification is explicit that external-load measures like TSS exist to estimate the biological stress an athlete already absorbed, not to prescribe the stress they should take on next [Mujika 2017]. Foster's monotony work is the same shape: it can tell you that low day-to-day load variance plus accumulated load is a risk pattern, and it will not restructure the week that produced it [Foster 1998]. Both charts are measurement instruments pointed backward. They are excellent dashboards and poor autopilots.

Be precise about Intervals.icu here, because it is the claim people most often get wrong. It is not analysis-only. It has a drag-and-drop calendar workout builder and a deterministic Annual Training Plan Builder that lays out base, build, and peak phases — real planning tools, and more than TrainingPeaks gives a rider with no coach. What it does not do is generate adaptive day-to-day workouts, or rebuild the plan when you miss a block. When a work trip eats Tuesday through Thursday, nothing recomputes. You open the calendar and move the workouts yourself, and you decide what the block should now look like — which is exactly the periodization judgment that is hardest to make about your own training [Issurin 2010].

The clearest evidence that this is deliberate is the ecosystem that has grown on top of it. IntervalCoach, Intervals Pro and Athletica all exist in part to bolt prescription onto Intervals.icu's open API, and its own forum runs a dedicated AI Tools section. A platform does not accumulate that many third-party layers for a job it was trying to do itself. For the self-coached cyclist the consequence is specific and worth sitting with: both of these tools solve the easy half of training without a coach, which is seeing what happened, and leave the hard half — periodizing the year and enforcing recovery when you would rather not — entirely to you.

04 / 04

Who should pick which

Pick TrainingPeaks if a coach is in the loop, or you want the vocabulary the sport speaks. Pick Intervals.icu if you are analytically self-sufficient and want the deepest free modeling in endurance sport. Pick neither if what you actually need is the plan written and rebuilt for you.

Choose TrainingPeaks, over Intervals.icu and over us, in three situations. You work with a coach, or expect to this season — it is their delivery surface. You intend to buy a structured plan from the Marketplace and follow it as written, accepting that even the Dynamic ones only shift dates onto your calendar rather than reshaping the week around what you rode. Or you are deep enough into the analytical craft that the PMC lineage and the coach-facing tooling are the point.

Choose Intervals.icu, over TrainingPeaks and over us, when you are happy making your own calls. If you know what a base phase should look like, you enjoy building the week, and you want to own your data through an API rather than rent a dashboard, nothing comes close on value — it is free and it is better at analysis than the paid option. Add multi-sport and the case strengthens: AdaptCycling is cycling-only, so a triathlete has a straightforward reason to pick Intervals.icu and not look back.

The third option only makes sense if the thing you are missing is the deciding. AdaptCycling is $15 a month or $150 a year, cycling only, and it writes the periodized plan from your real ride history then rebuilds it when the week breaks — with a chat coach that remembers your season across months. It does not try to out-analyze either platform above, and it will not replace a good human coach. Worth being straight about the pricing: there is a 14-day trial with no card, after which the free tier is read-only. It answers a different question: not what did my training do, but given that, what should the next eight weeks be.

Common questions

Quick answers

Is Intervals.icu really free?

Yes, the core platform genuinely is — fitness tracking, activity and interval analysis, the training calendar, the workout builder, and the integrations all sit in the free tier. There is an optional Supporter tier at $4 a month that adds weather analysis, the annual training plan builder, and early beta access [Intervals.icu 2026]. It is not a time-limited trial and there is no card gate on the core.

Does either one write a training plan for you?

Neither writes and adapts one on its own. TrainingPeaks expects a coach to author the plan or expects you to buy a static one from its Marketplace. Intervals.icu gives you real planning tools — a workout builder and a base-build-peak annual plan builder — but you make the periodization decisions and you move the workouts by hand when life disrupts the week [Mujika 2017].

Why do the two platforms use different names for the same charts?

Terminology, not method. CTL, ATL, TSB, and TSS are TrainingPeaks terminology, so Intervals.icu calls the equivalent quantities Fitness, Fatigue, and Form. Both descend from the same fitness-fatigue modeling lineage [Morton et al. 1990]. If your numbers differ slightly between platforms it is usually down to FTP settings or which activities each one ingested, not a disagreement about the underlying math.

Can I use both at the same time?

Plenty of riders do, and it is coherent if you assign each a job. TrainingPeaks becomes the surface you share with a coach; Intervals.icu becomes the place you actually interrogate the data, because the custom metrics and power-curve models go deeper. Both ingest from the same upstream sources, so the duplication costs you setup time rather than data quality.

Which is better for a rider with no coach and limited time?

Intervals.icu, on price and depth, if you are willing to make the training decisions yourself. The caveat is that limited time usually means an unpredictable week, and a manual calendar is precisely what stops getting maintained when the week goes sideways. If you find yourself repeatedly not rebuilding the plan after a disrupted week, the problem is not the analytics tool you chose [Foster 1998].
References

Sources cited in this guide

  1. 01
    Morton et al. 1990. Modeling human performance in running. Journal of Applied Physiology.
  2. 02
    Mujika 2017. Quantification of training and competition loads in endurance sports: methods and applications. International Journal of Sports Physiology and Performance.
  3. 03
    Foster 1998. Monitoring training in athletes with reference to overtraining syndrome. Medicine & Science in Sports & Exercise.
  4. 04
    Issurin 2010. New horizons for the methodology and physiology of training periodization. Sports Medicine.
  5. 05
    TrainingPeaks 2026. Premium Pricing for Athletes. TrainingPeaks.
  6. 06
    Intervals.icu 2026. Intervals.icu — free training analysis and planning platform. Intervals.icu.
Compare head-to-head

See the direct comparisons

In this series

More inside The self-coached cyclist

Start here · Foundational guide

The self-coached cyclist: training without a coach in 2026

What self-coached actually means in 2026, why most amateurs plateau in year two, and how to structure a training year without a personal coach.

Read the full guide

Other articles in this series

  1. 01

    How to restart cycling training after two weeks off

    When you miss two weeks on the bike, the question isn't whether to resume — it's how to restart without overshooting the next two.

  2. 02

    How often to take a recovery week as a self-coached cyclist

    The 3-on/1-off recovery-week cadence is a guideline, not a law. When self-coached riders should hold it, push it, or deload sooner.

  3. 03

    Am I overtrained or just tired? A self-coached cyclist's guide

    Functional overreaching, non-functional overreaching, and OTS — what each looks like, and when fatigue crosses into something more serious.

  4. 04

    How to spot and fix junk intensity as a self-coached cyclist

    Most amateur rides drift into the medium-hard zone you can't recover from but don't adapt to. How to spot junk intensity — and three structural fixes.

  5. 05

    Why year two stalls: junk intensity and the amateur plateau

    Year-one gains came from any training. Year two stalls when intensity drift inverts the 80/20 rule. The mechanism — and the fix.

  6. 06

    Cycling training plan for an irregular schedule

    Shift work, a new baby, and weekly travel break the standard 7-day training week. How to plan around an unpredictable schedule.

  7. 07

    What weekly TSS should an amateur cyclist actually target?

    TrainingPeaks charts make weekly TSS look like the goal. For most amateurs it's the wrong primary target — here's what to use instead.

  8. 08

    Safe CTL ramp rate for amateur cyclists: how fast is too fast

    How fast a self-coached cyclist can grow CTL without crossing into non-functional overreaching — the numbers, the signals, and the override rules.

  9. 09

    The cheapest way to self-coach cycling in 2026

    Free apps cover most of self-coaching. The one tool worth paying for, where the false economies hide, and the cheapest credible stack in 2026.

  10. 10

    When self-coached stops working: signals it's time for a coach

    Self-coaching works for most amateur cyclists — until it doesn't. The four honest signals you've outgrown DIY, and the cheaper fixes to try first.

  11. 11

    FTP test vs power curve: should self-coached riders test?

    When the self-coached cyclist actually needs an FTP test versus when the power curve is enough — a judgment-call framework with research backing.

  12. 12

    Self-coached 12-week training plan for a goal event

    How a self-coached cyclist builds a 12-week base/build/peak/taper block for a goal event — the math, the workouts, and the taper that holds the peak.

  13. 13

    Polarized training for amateurs: making 80/20 actually work

    What 80/20 means in the three-zone model, why it's hard to run on 5-7 hours a week, the pyramidal counter-evidence, and how to execute it.

  14. 14

    Is TrainingPeaks worth it for a self-coached cyclist?

    TrainingPeaks is the gold-standard analysis platform — but for a self-coached rider with no coach, is it worth $20/mo? An honest verdict.

  15. 15

    TrainingPeaks free vs Premium: what the free tier gives you

    What the free TrainingPeaks Basic tier does for a self-coached cyclist, what it withholds, and whether Premium or a free alternative wins.

  16. 16

    How long should your taper be? What the evidence shows

    Three canonical sources give three different volume cuts, and nobody has ever tested a personalized taper against a standard one.

  17. 17

    Garmin bought TrainingPeaks: what it means if you self-coach

    Garmin now owns TrainingPeaks. What actually changed on July 22, 2026, what's still open, and how a self-coached rider should read it.

Free training analysis · No card · ~3 minutes

Try the adaptive coach yourself.

Connect your rides and the coach reads your last eight weeks — intensity balance, ramp rate, what's working, what's holding you back — then drafts your training plan around it.

Analyze my training→

Free 14-day trial, no card.