Indoor and Outdoor TSS


I’ve got a question about TSS :slight_smile:

I’ve just started using TR and have done my first ramp test which has given me my FTP but its much lower than my outdoor FTP, I’m not quite used to the trainer yet! Alongside TR I’m also using Training Peaks to track both my indoor and outdoor workouts and therefore using it for fatigue, form and fitness calculations which are calculated using TSS. As my FTP is lower indoors when my workouts are transferred to TP they show up with a lower TSS than TR had predicted for the workout.

So my question is this, can I change the TSS in Training Peaks to what TR had predicted to ensure that the fatigue, form and fitness numbers are accurate? Does this effectively simulate doing the workout outside with my outdoor FTP? If TSS calculation uses FTP, NP and IF then maybe it can just be translated across from indoor to outdoor FTP’s or vice versa for that matter.

What setups are you using indoors on TR versus outdoors? Can you use the same power meter ?

I have a Wahoo Kickr Core indoors and I use Powertap P1 pedals outdoors. I haven’t tried using the pedals indoors yet but I’m confident that they track well, DC Rainmaker said so ha! I think the low outdoor TSS is the difference of the two FTP’s not necessarily what the power is being recorded on inside or outside. I’m using the same reasoning that a TR workout gives any athlete the same TSS for a workout regardless of FTP because it’s all relative. I think that makes sense :upside_down_face:

I’d recommend checking out this thread; there has been a good amount of conversation on this topic :slight_smile:


My main question about this everyone says one hour inside equals two hours outside, the TSS value don´t show that so my training stats, and form are not corrected or even close.


No, “everyone” does not say that. There are general comments that inside riding and workouts can be more demanding for a similar time spent outside. This comes from a variety of factors from cooling, rider motivation, more likely coasting breaks outside, differences in moment/inertia between bikes outside and trainers, typical ride terrain for each rider as well as others.

I’ve seen more reputable comments form coaches and notable cycling experts that range from equal (no difference) to 1.25 or even 1.5 times as a potential multiplier for inside vs outside workouts and rides.

But as I said, it is highly dependent on a range of factors. Maybe 2.0 is real for some riders, but I doubt it is common and it is definitely not considered absolute by and for everyone.

In short, there is no simple answer as it will likely vary. Inside is often “tougher”, but not always.

Thanks for the reply “The Other” Chad :slight_smile: but even if it´s 1.25 when i see my TrainingPeaks i am always not reaching the TSS values because Sunday Bike Ride before was 3 hours and now only 2 hours so the TSS will be way different.