Four five-minute efforts can feel very different by the end of a ride. Compare their power, duration and heart rate, then return to the recording to see what happened inside each average.
Images show synthetic training data on the Bormio–Stelvio cycling route in Italy.
Keep each effort beside the data
Open a recorded activity in the web app and expand Breakdown. Its interval cards put the efforts on a shared timeline, so you can distinguish each work block from the recovery that follows it. Turn on the ranges you want to inspect through Intervals; recorded Laps have their own controls.
The cards stay directly above the data as you switch between Overview, Power, Heart rate, Terrain & Ride Dynamics and Other sensors. Their metrics follow the selected tab. You can keep the same intervals in view while looking at a different part of the recording.
The four power averages are close together. Heart rate tells a different part of the story: the first work range averages 178 bpm, while the later three show 174 bpm. These values let you describe the recorded efforts; they do not establish why heart rate differed or whether the rider was more fatigued.
Cards keep the range name and its summary together. Depending on the sport and recorded streams, you can inspect duration, moving time, power, power relative to FTP, heart rate, speed or pace, elevation, distance and cadence. A ride with power and HR lets you compare output and response. A run with pace and HR offers a different set of measurements. A missing sensor value remains unavailable.
Manual interval comparison is included in Free. There is no shared five-item cap with whole-activity comparison: the interval workspace belongs to this recording. It does not create an arbitrary manual selection of intervals from several activities.
Use the list to choose what appears
The interval list is useful when you need to locate a named range, read its duration or change its visibility before comparing it with the others. It follows the activity timeline. The switches control which intervals appear in the charts and statistics; they let you keep work and recovery separate without removing either from the recording.
For more context, examine the highlighted ranges on the aligned charts and GPS map. A summary can tell you two efforts had similar average power; the recording lets you inspect what happened inside those averages. Available chart metrics and visibility settings are explained in Activity Analysis.
The list is not a spreadsheet with arbitrary column filters or independent sorting, and the cards do not provide those controls either. Their order preserves the chronology of the activity.
A lap, a manual range and a detected effort are different
The intervals you compare can come from several places. Recorded laps use boundaries supplied by the device or imported file and appear in the separate Laps list. If the file contains no laps, there are none to display. Manual intervals are named ranges you define yourself with elapsed-time boundaries.
Automatic detection searches the recorded streams for effort patterns, climbs or repeated route sections. Its results are proposed ranges, not a replacement for the original laps. Private Segment passages have another origin: they match a route section you previously saved to your account.
That distinction matters when you revisit a familiar road. Detecting a repeated route section looks for repetition inside the current activity. Recognising a Private Segment uses your saved definition and lets you follow passages across your history.
Give a range a useful name and precise boundaries
Use Add interval when you know which part of the recording you want to examine. Enter the elapsed-time boundaries, name the range and save it. For an editable interval, Edit lets you revise its name or bounds; inspect the preview against power, HR or pace before saving.
These edits are available for athlete-authored and eligible detected ranges. Imported source laps and protected source-derived intervals do not all expose the same actions. Delete is offered only where the range is editable. Changing a label makes the interval easier to find; it does not change the sensor measurements inside it.
Find efforts when the recording has no useful lap markers
You do not have to draw every interval yourself. Choose Detect intervals from the activity’s Intervals list and select the kind of pattern you want to find. For a ride with a power meter, steady power can help separate work from recovery. For a pace-based session, the speed stream supplies different evidence.
| Detection mode | What it finds | What the recording needs |
|---|---|---|
| Steady power | Sustained power levels and changes between work and recovery; it can resolve regimes from 20 seconds | Power samples |
| Steady pace | Sustained speed that differs from the surrounding activity, with candidates lasting at least 90 seconds | Recorded speed |
| Steady heart rate | Sustained HR levels distinct from the surrounding effort; candidates last at least 180 seconds, allowing for delayed HR response | Heart-rate samples |
| Climbs | Sustained ascending sections | Altitude and distance evidence; a GPS trace alone is insufficient |
| Repeated route sections | Similar passages over the same part of this recording’s route, with repeated sections of at least 500 m | Usable GPS geometry and sufficient route length |
| All | The applicable effort, climb and route searches, with overlapping candidates resolved | The inputs actually present in the activity |
The available modes depend on the recording. One detection pass returns at most 60 resolved candidates. This is a limit on the search result, separate from any comparison or plan limit.
Check the proposed intervals before using them
A search first enters the queue, then runs. A queued or running status means processing is unfinished. When it completes, inspect the proposed bounds against the charts before treating them as the intervals you intended to compare.
High-confidence detections can be accepted automatically. Suggestions needing review remain available in the interval drawer, with Accept, Decline and bulk review actions. Where a suggestion is editable, you can correct its name or bounds first; save that edit before accepting it.
Resolve an outstanding review before starting another search. No reliable intervals found leaves the activity unchanged. Existing intervals and overlap resolution can also mean a later pass adds nothing. An error offers retry, but an unfinished search is not a completed comparison.
Take one effort into your own history
Once an interval is worth revisiting, open its More actions → Find similar intervals. This Pro search uses that one range to find comparable intervals in your own same-sport activity history. You do not have to select several whole activities first.
Results contain up to 50 matches, with at most 3 per activity. The search considers comparable duration and recorded output. Power comparison needs adequate coverage and uses weighted power for sufficiently long ranges. Usable route geometry adds spatial evidence: matching checks the endpoints and passage shape, not just whether a GPS point happens to be nearby.
The history you have imported determines what can be found. This automatic search is separate from manual interval comparison on Free. For a hand-picked set of whole sessions, including the separate temporary FIT-file workflow, use Activity Comparison. An unrestricted manual basket of arbitrary cross-activity intervals is not part of the workflow described here.
Keep a section you want to ride or run again
Sometimes the useful comparison is tied to a place: the same climb or section of road on another day. Start from an interval with usable GPS and choose More actions → Save as segment. Give the section a name and choose Same direction or Both directions.
A definition needs at least 3 usable GPS points, a section of at least 100 m, and distinct endpoints. Free includes 3 tracked segments; Pro permits more. Saving a section does not add missing GPS to old recordings.
After saving, open Private Segments to inspect recognised passages. The passage history keeps each result linked to its activity, so you can examine the effort in its original context. That is a continuing record of a saved place, rather than another way to select intervals inside one workout.
Know which comparison you are opening
Within one activity, the interval list and Breakdown cards compare the ranges you show. Find similar intervals searches your history from one range. Find Similar Activities searches for whole-session matches. Activity Comparison lets you select up to five whole activities and has a separate one-file temporary FIT comparison. Private Segments follows passages of a saved route section.
If a metric needs more explanation, Weighted Power describes why a variable effort can differ from its ordinary average; Power Intensity explains the FTP-relative value. For differences between products, see Intervals.icu vs EffortSignal.
All Pro features are free through January 31, 2027. No credit card or automatic charges. After Early Access, keep using Free or choose Pro. See Free and Pro plans.