Indoor vs. Outdoor Training (TSS)

Hi everyone!

I was wondering why when I train outside my tss score is a lot higher than an indoor trainer road session.

For example:
Outdoor group rides I get a tss score of 130
2hrs 46.31mi 198 Power 232NP

Indoor sweet spot 3.8 I get a tss score of 65
1hr 23.75mi 219 Power 240NP

Additionally now my HR goes a lot higher when I’m outdoors vs when I used to train solely outdoors.

1 hour = 65 TSS
2 hours at about same intensity = about twice the TSS = about 130 TSS


As @WindWarrior indicated TSS is a function of intensity and duration. Increase one or both will increase your TSS score.

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Got you thanks for the info!

Any idea what could be happening with HR?

More short bursts of power? On SOLO rides my HR goes a little higher outdoors, from short power bursts due to traffic or corners or more frequent standing. But usually my HR is only a little higher during SOLO workouts, because my power graph looks very similar inside vs outside.

Group rides? Yeah generally I see a lot more bursty power on a group ride. Higher highs and lower lows. That will drive my HR a lot higher.

For example:

you can see I was riding by myself on target (a range of power) until around mile 11. Then I saw the group ahead and increase power to slowly catch them around mile 18. So the first half of the power graph looks pretty similar to riding inside on the trainer. And HR is similar inside vs outside.

Once I’m with the group, my power graph gets “messy” and HR tends to go up. Around mile 30 I split off to return home and you can see it starts looking more like inside again.

Stress of traffic, road furniture, changes in gradient, wind direct etc etc etc
Indoors, you can shut your eyes and relax… :stuck_out_tongue_winking_eye: