How does adding a running profile affect xss requirements for cycling?

I currently import my outdoor run workouts from Strava directly into my existing bike profile. This gives me xss credit toward my xss requirements, which I find to be a good thing. At age 75, my recovery time is generally longer than it would be for a younger athlete. I need to train in both sports, but normally choose one or the other on a given training day.

I’ve been told in this forum that I should have a separate profile for running, but I have the impression that running will then NOT contribute to the existing xss requirement for the bike. In effect, the combined requirement will increase, but I may not be up to it.

I’m in the Continuous Improvement program and have chosen a Maintenance weekly improvement rate. None the less, I have seen improvement, last gold breakthrough a week ago.

I also can’t understand having two profiles. In fact, it seems antithetic to a lot of other advice given out on the forum - e.g. “Use a high intensity workout to mimic the stress load of weightlifting and its impact on your cycling”. Surely running has more carryover to cycling?

I ran two ultramarathons over the last six days. I use one profile. Forecast AI gave me an XSS for them (which I think was slightly underestimated vs HR TSS or RTSS) and then gave me a day off after each one. If I’d put them separately, it would have told me to do 1min repeats at anaerobic power the day after.

Combining two profiles is something we have not yet been able to implement due to the complexity of the calculations. It’s really easy to just generate running low, high and peak XSS values and add them up into your cycling profile. But we can’t do that because you can’t combine them this way meaningfully. Running affects cycling’s training and recovery loads in one way and cycling affects running’s training and recovery another way. Since we prescribe training based on training and recovery loads, across 3 dimensions, you might imagine that combining the two might prove to be difficult, if not impossible and all your training is based on having this data accurate. So rather than just adding them up and saying “off you go”, we don’t pretend that it works this way.

Our advice for combining running with cycling is not to use your actual running data in the cycling profile and vice versa but rather account for the them manually. Yes it’s more work but it will give you better idea of how you’re progressing each individually towards their goals. If you just need them added up, then combine Xert with another platform that does that for you (we won’t because it’s wrong to do so).

so rather than adding them up
if you need them added up combine xert with another platform we won’t because it’s wrong to do so

Can I ask in this case why you offer:

Weight Training “Workout” - General - Xert Community Forum (

As best practice for weight training?

I would say that a large (maybe overwhelming?) proportion of cyclists just want a way to understand the impact going on a run is going to have on their training and so how they might modify their cycling in and around said run to avoid burnout and over/undertraining.

Last weekend’s 60k run generated 364 XSS. My HRTSS was 351, and rTSS 360. I knew the effort type, so I went in and edited the activity type to be “Mixed” vs “Pure” endurance.

I was knackered. What value would I have gained by logging this to a running profile and then manually adding, what, how many XSS to my cycling profile? How would I account for the fact that some was spent above threshold, some below? What profile would I use? How would this be more accurate than the Xert estimate from the start?

The simplest solution is to simply key in the XSS (and as you identify also a focus and specificity) into your cycling profile. The XSS, Focus and Specificity from a run with power data isn’t like what it would be for cycling and the actual amount of strain from running that influences your cycling is also not something that can be easily calculated from the running power data. Add in a further abstraction of using HR, and it gets more challenging.

Note that if we automate the adding of a run into cycling profile, it also means we’d need to account for your cycling in your run profile. If your cycling XSS improved your running signature, your XSS would be different that was it was calculated as. If so, then the XSS from your run into your cycling is less. … and thus is rat’s nest that is the challenge. It’s simply not that easy and just doing it uni-directional with reasonable guesses is tons better than making this all automated.

Wrt to the weight training workout, it’s just a way to add in strain from weight training. It’s uni-directional as we advise. Did my sprints the other day make my legs stronger for my gym workout? Probably and making all this math work is simply not something we can tackle atm with the small team we have. We did take a run at it a few years ago and decided we needed a much larger dev and test team to make it happen. One day…

you said: "Our advice for combining running with cycling is not to use your actual running data in the cycling profile and vice versa but rather account for the them manually. "

Please explain how to do that - I have no clue.

I’m a short distance triathlete (typical race would be half mile swim, 20K bike, 5k run). Typical training would be 30 - 45 min Xert indoor bike workout OR 2 - 3 mile street run (usually w/ short hills), OR 3 - 4 miles of interval training on a running oval, OR 2000 yd. pool or 1 mile Ocean swim. Try to get in 4 - 5 training days / week. May start stacking bike - run ( “brick” - as a friend explained B is for Bike, R is for Run, and ‘ick’ is for “ICK!” ) as the weather calms down a bit this spring.

I’m 74 (now in the 75 -79 age group) , and primary goal of training is not to get worse as I age. Running is by far my worst sport, and the one that degrades the most quickly if neglected.

I’ve chosen ‘climber’ as my bike ‘focus’ because I totally suck at it - have the most to gain by becoming stronger in climbing.

If you are using only heart rate for your runs, you can sync your runs into your cycling profile but ensure you do not have HRDM enabled on your cycling. Then click on the run in the Planner and key in an XSS number that you feel would apply to your cycling from each run. An example would be to use 40XSS per hour and likely use Endurance focus if the run was just a regular endurance run. If the run was a high-intensity workout, you could up the rate and choose a Climber or GC Specialis focus. Again you’d have to experiment a bit with it.

If you are using running power, then set up a separate profile with separate fitness signature and take your run’s XSS and factor it down by maybe 10-20% into your Cycling profile. So if it was a 100XSS run based on your power data, use 80-90XSS into your cycling profile and stay with the same Focus/Specificity. Unless you intend on doing a long period of just running and no cycling and you want that to be properly reflected into your cycling fitness profile when you start up again, the precision isn’t that important.

Note that the fatigue from running is higher than what gets accounted for in just the XSS numbers so you might need to increase your Recovery Demands and/or adjust Freshness Feedback if you’re using the Adaptive Training Advisor. Optionally, simply following what you’re feeling and choosing appropriately is just as good. Only issue is having a well identified ramp up towards a goal like XFAI does will be difficult to create. You’ll need to go more by feel than have a predictive plan of fitness gains.

Hope this helps.

How is this strategy meaningfully different from allowing XERT to give you a HR XSS for the same run and adjusting the “Focus” appropriately?


Here is a 57k trail ultramarathon I ran (average HR 157, some shorter threshold periods but mostly at tempo) given 364XSS based on XERT scoring.

This is the same run on

They all seem to align pretty well to me?

Because 1 running XSS does not equal 1 cycling XSS. You can’t substitute your cycling training with running and expect the same results. Whether the calculations are similar or not, has no bearing on this.

Don’t know where to check / edit HRDM, but the HR Derived label that appears on runs, swims AND actual road rides (no power available), does not appear on my trainer rides (Trainer has power, and does a pretty good job of keeping near the target Watts in Xert interval workouts), so I suspect that it’s already disabled any activity that doesn’t provide power.

I don’t have power on my road bike, only on the trainer (Inside Ride). For various personal reasons, I’m doing most of my bike training indoors these days, so HRDM is not applied to those, but will be applied to the occasional road ride (which I hope will become more common further into spring. )

On rethought, what you can do it leave HRDM enabled but make a habit to modify the XSS, Focus and Specificity of the other non-cycling rides you record. Perhaps take it down to 80-90% for runs and maybe 10-20% for swims. Leave the HRDM ride data as is. This should work well to keep your cycling training loads up-to-snuff and better predict your cycling performance outcomes.

OK sounds like a reasonable plan, though I don’t actually know how to modify ‘specificity’ and ‘focus’, or what I would modify them to. I guess change focus to ‘endurance’ rather than ‘climbing’ ? There’s a lot about Xert that I don’t really understand, but just assume will provide some useful guidance as xss surplus or deficit.

The xss with HRDM on swims is already pitifully stingy, and I suspect somewhat arbitrary, in as much as HR has to come from the Apple Watch, which is less accurate than a chest strap, and probably even less reliable when wet. An HR strap with built in memory that records HR during swims, and then somehow magically uploads it to somewhere when you’re done (b/c blue tooth doesn’t work in water) can be obtained, though I’m not sure the xss from swims will ever be large enough to affect much of anything else.

My running app on Apple Watch provides power data, albeit rather meaningless. Am I right in thinking that this means I can’t edit the XSS, will I need to strip out the power field first? I do find having the running data useful in the cycling profile, and I don’t do enough runs to make the errors problematic.

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I had never noticed that the Apple running app provides power. Sho’ nuff’ ‘Fitness’ on my iPhone shows avg 149 W for a recent 2 mile run, which seems plausible for the perceived effort, and also matches the avg. power reported in Xert for the same activity.

Apple Fitness uploads to Strava, and Xert syncs to that. Strava is not showing power (or I haven’t figured out where to look).

Xert indicates ‘Heartrate Derived’. Of course, power in the Fitness app, must also derive from HR perhaps together with pace and elevation, so it’s possible that the matching 149 W is a result of both Fitness and Xert modeling the same data, even if the result isn’t passed through by Strava.

Curious to know what’s really going on here ( @xertedbrain ?)

Probably because I use Workoutdoors app via Healthfit. They must pass the power somehow.