The short answer
If you coach yourself and mostly want to see your fitness, fatigue, and form, go with intervals.icu. It gives you the analytics that used to cost real money, for free, and it pulls from Strava automatically. If you work with a coach, or you want professionally built training plans from a marketplace, go with TrainingPeaks. Plenty of people end up using both, and that is a perfectly reasonable answer too.
Price is the headline
intervals.icu is free. Not free-for-now, not a stripped trial. The fitness and fatigue modeling (CTL, ATL, TSB), the power curve, automatic interval detection, the calendar, the workout builder, and Strava sync are all in the free tier. There is an optional Supporter tier at $4 a month that adds extras like weather analysis, an annual plan builder, full Strava history import, and fully custom zones. None of that is the stuff you need day to day.
TrainingPeaks has a free Basic account, but the features people actually come for sit behind Premium. That runs $19.95 a month, or $134.99 a year if you pay annually (the annual price went up from $124.99 in 2025). Premium is what unlocks the Performance Management Chart, the deeper analytics, annual planning, and sending structured workouts to your device.
Feature by feature
| What you get | intervals.icu | TrainingPeaks |
|---|---|---|
| Price for the good stuff | Free (Supporter $4/mo) | Premium $19.95/mo or $134.99/yr |
| Fitness, fatigue, form (CTL/ATL/TSB) | Free | Premium |
| Power curve, interval detection, custom charts | Free, very deep | Premium |
| Structured workout builder | Free | Premium, very polished |
| Annual planning | Supporter ($4/mo) | Premium |
| Push workouts to Garmin and Wahoo | Yes | Yes |
| Coach tools and plan marketplace | Light | The industry standard |
| Mobile app | Basic, web is the strength | Strong on iOS and Android |
| Automatic Strava sync | Yes, native and free | No, expects your device instead |
How each one handles Strava
This is the part that matters most if you live in Strava. intervals.icu connects to Strava directly. You authorize it once and new activities flow in on their own, free for everyone. Importing your entire back catalog is the one Strava-related thing held behind the $4 Supporter tier, but recent activities sync without paying anything.
TrainingPeaks does not really pull from Strava the same way. It expects your device to feed it, so the usual setup is to connect your Garmin or Wahoo straight to TrainingPeaks. A lot of people just point their Garmin at both TrainingPeaks and Strava at the same time. It works, it is only slightly more setup, but it is worth knowing going in: intervals.icu is the more Strava-native of the two.
Where intervals.icu wins
Value, obviously, but it is more than that. The analytics are genuinely deep, the charts are endlessly customizable, and the Strava sync just works. For a self-coached athlete who likes poking at their own numbers, it is hard to beat and slightly addictive.
Where TrainingPeaks wins
Coaching. If you have a coach, odds are they already use TrainingPeaks, and the back and forth between athlete and coach is what the platform was built around. The plan marketplace is also real: you can buy a structured plan from a pro for your goal race. And the mobile app is the more finished of the two. If your training lives on your phone, that counts.
So which one?
Pick intervals.icu if you are self-coached, curious about your data, and would rather not pay a subscription to see your own fitness. Pick TrainingPeaks if you have a coach who uses it, you want a plan from the marketplace, or you want the better mobile experience. Paying for TrainingPeaks is worth it when a coach or a bought plan is part of your setup. If it is just you and your numbers, free intervals.icu covers almost everything, and the $4 tier covers the rest for a fraction of the price.
Common questions
Is intervals.icu really free?
Yes. The core platform, including fitness and fatigue modeling, the power curve, interval detection, the calendar, and Strava sync, is free with no time limit. The $4 a month Supporter tier adds extras like weather, an annual plan builder, and full Strava history import.
Can I use both?
Yes, and a lot of people do. Use TrainingPeaks to work with a coach or follow a bought plan, and use intervals.icu for free deep analytics on the side. Point your device at both and you are set.
Does intervals.icu replace TrainingPeaks?
For a self-coached athlete focused on analytics, mostly yes. It does not replace the coach workflow or the plan marketplace, so if those matter to you, TrainingPeaks still has a job.
How much is TrainingPeaks Premium in 2026?
$19.95 a month, or $134.99 a year if you pay annually. The annual price rose from $124.99 in 2025.
Related reading
intervals.icu also earned a spot in our roundup of the best free Strava apps. If you want to keep looking, you can browse every training analytics tool in the directory, or see how each one connects to Strava.