A shorter ride is not the whole story. Put recordings side by side to see how duration, distance and recorded effort changed, then compare what you sustained over different lengths of time.
Images show synthetic training data on the Bormio–Stelvio cycling route in Italy.
Choose a useful reference ride
Start with a recording you want to understand: a recent attempt at a familiar climb, a regular run, or a session you repeated. In the web app, open the activity and choose More actions → Compare. That activity becomes the reference and stays selected while you add others.
Under Recent, search your own history by name, context or tag. The list contains activities of the same sport. Select up to four more and press Compare: the limit is five activities in total, including the reference. This manual comparison of saved activities is included in Free.
You choose what makes the sessions comparable. A repeat route is useful for reviewing time and effort together; two different routes may be more useful for comparing duration or recorded intensity. The selection itself does not establish that the terrain or conditions were the same.
Read the differences against that reference
The reference is the first row. The other selected activities follow from newest to oldest, with percentage differences beside comparable values. Each difference is measured against the reference, rather than against the row immediately above it.
Use Settings to choose the columns and arrange their order. You can drag them or use the up and down controls, then Apply the layout. Restore defaults returns to the starting selection for that sport. Cycling starts with speed and power alongside time and distance; running uses pace, and other sports have their own relevant defaults. The example keeps seven columns so the main differences are easy to read.
Avg power describes the average across the recording. Weighted Power gives a different view of variable effort. A faster time with higher power, as shown here, describes a harder ride; it does not by itself establish why performance changed. Missing sensor values remain unavailable, not zero.
Use Back to selection to change the recordings. Export CSV downloads the comparison table with its chosen columns when you want to work with those values elsewhere.
Compare efforts of the same duration
Whole-ride averages can hide a strong short effort or a sustained block. Below the table, Duration curves compare the available power and heart-rate bests for each recording. The horizontal axis is the length of an effort, not the time of day or distance along the route.
A ten-minute point describes the best recorded average for an effort that long; it does not mean the first ten minutes of the ride. Heart rate curves use the same duration approach in bpm. These views compare recorded efforts and are not a synchronised overlay of every raw stream. A steady ride also need not contain a maximal effort at every duration.
Power curves require power data; heart-rate curves require heart-rate data. While the comparison loads, the interface shows its progress. A failed curve request offers Retry; an activity without usable curve data cannot contribute that curve. Those states are different from a low measured value.
Compare a file without adding another activity
For a recording outside your saved history, switch Compare to → FIT file. Drop one file into the window or use Choose FIT file. This is a Pro capability, separate from the Free comparison of saved activities.
The file must be from the same sport and no larger than 64 MiB, labelled 64 MB in the interface. It is analysed temporarily: the file is not saved to your activity history and does not change your profile metrics. Empty, malformed or unsupported files can fail before a result appears. Use ordinary activity import when you want to keep a recording in your history.
Choose the right scope for the question
This comparison uses whole activities. To inspect one climb within longer rides, use Private Segments. To work with selected efforts inside a session, open Interval Analysis and Comparison.
If you want EffortSignal to search for candidates instead of choosing them yourself, see Find Similar Activities. That automatic search has its own Pro access and limits; it does not expand the five-activity limit of this manual comparison. Current Free, Pro and Early Access terms are on the pricing page.
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.