I did my first Group Workout last night, Tempo with 30-second Spikes, and, although I found being in a group and the banter motivating, the kilometres I ended up logging (22km for 55mins at 260W average at 80kg) were a bit disappointing compared to doing a workout solo.
I understand that the group is kept together at the same speed but surely it would be more motivating for all if the group’s speed was based on the strongest rider/s?
I just completed a group workout this morning and it looks to have undercounted my miles by about 50 percent. To get a rough estimate of ‘unadjusted’ miles, I counted my laps around the course (Jungle Loop) plus the lead in, and got 19.28 versus the 13 showing on the ride report. Probably not exact but it sounds about right based on my normal pacing.
If I can do that manually, why can’t Zwift Include an ‘equivalent miles’ box in the post-workout feedback? It’s not that hard.
Is there something I’m not thinking of though?
Just remember, distance covered doesn’t matter in a workout, you get XP by successfully completing the blocks in the workout (those stars next to each block of work) and it is based on time spent in specific effort zones.
I don’t really like the rubber band effect, so I don’t bother with group workouts. Even though the distance doesn’t count for XP in a workout, I still feel better if I’m travelling the expected amount of distance, and my monthly distance goal is also a metric I use.
Distance tracking in erg workouts is meaningless. Changing which gear you do the workout on changes the distance, while keeping the workout exactly the same otherwise.
Thanks Mike and I totally agree - my primary interest in tracking miles is to measure progress against my monthly and annual distance goals. So far my workaround has been to add an ‘adjusted miles’ column to my manual log spreadsheet. A little clunky, but it works okay.
How do you account for adjusted miles?
It’s only a rough estimate, but I compared a sample of group workouts to similar rides I had taken solo with similar metrics (same course, similar duration, average power output, total calories, elevation gain). I also compared my posted speed during a group workout to my posted speed under the same conditions riding solo. I did this for multiple scenarios. I tried to keep everything as comparable as possible so as to isolate the miles only.
There was a little variation but it was reasonably consistent: on average, it looked like the group workout miles showing were about 2/3 to 70% of what they would have been otherwise. I imagine from person to person and from group to group this may vary, this is just where my numbers seemed to land.
So on my spreadsheet log, I show posted miles, but added an additional column to show the equivalent in ‘normalized’ miles. Does that make sense?
ultimately you’re not going anywhere, you’re on a trainer in a virtual world. 0 miles traveled.
Well, true, there is that…
Though cyclists often track their miles IRL, whether they’re from races, group rides or training sessions. Or for equipment maintenance reasons.
I’m intrigued though by you saying that a gear change in ERG mode somehow would change the distance? How would Zwift know what gear I’m in on the bike?
You are right as far as Zwift is concerned, since it does have an algorithm to calculate speed as a function of power, slope, and rider info (weight, height, bike characteristics). Distance in a Zwift workout then entirely depends on which course you take, everything else being equal - unless you do a group workout, and then it’s more of a random thing depending on who else is riding.
In most other means of doing workouts on a smart trainer in erg mode (TrainerRoad, Tacx app, a Garmin or other head unit, etc), using a longer gear yields the same power but a higher speed, and therefore distance becomes a function of which gear you select to do the workout.
I found that a recent group workout, the miles seem correct, just that Zwift seemed to make my speed a lower than should be value (eg. 11mph seems to be consistent average whether on a 1 mile decline or 1 mile incline, or whether less or more wattage segment of the workout).
I’m still for some reason not getting it. Sorry. Why would any app assign more speed to the rider based on the gear one’s in, and not the power output? Also not sure how any app would know what cog or chainring that the chain is sitting on?
Because most apps don’t have an algorithm to calculate speed as a function of power. They just measure wheel speed. Try it with a Garmin head unit. Go in erg mode at a given power. Change gears. Look at the speed. Tell us what you see.
The apps do t know which gear you’re in. But your wheel speed does. And it increases if you use a longer gear at a set power (and the power remains constant in erg mode).
I’d just add that erg mode is a secondary issue in this statement. Your Garmin or other head unit reports speed and distance based on how fast the rear wheel, virtual or otherwise, is turning, and for how long. That’s true no matter what gear you’re in, and whether or not you’re in erg mode. And that speed and distance does not represent outdoor riding, since it doesn’t account for air resistance or, on direct drive trainers, rolling resistance.
Erg mode does also influence comparison of the “speed” of the indoor rear wheel, of course, since switching to an interval pushing 300 watts in erg mode in a 53x11 gear turns the “rear wheel” at a different RPM than 300 watts in a 30x30 gear.
Are you talking about an imaginary wheel in instance where we’re on a direct drive trainer where there isn’t really a rear wheel?
Replace “rear wheel” by “rear hub” and there’s no virtual left in the discussion.
Ok, so I never realized that a smart trainer reported the actual speed that the rear hub or flywheel or whatever it is is spinning at. Thought it just measured cadence and power and then interpolated speed. With Zwift it is also accounting for your weight and the course incline etc. With other apps, I would have thought it would have done the same but just assumed a flat course and arbitrary avg weight (flat ground where rider weight isn’t same factor as for up/down hills)
Actually, smart trainers only report wheel speed (as well as power, and cadence in some cases). Apps can do whatever they want with this data. If you take TrainerRoad as an example, the app does not display speed; but since the trainer broadcast it, speed is part of the output file, and Strava will show a distance traveled for your workouts. You would get the same result if you recorded the session with a head unit. This also explains why a head unit will give very different speed and distance results than Zwift, regardless of the activity: the former is based on wheel speed, the latter on a power-to-speed calculation.
This is actually not true… Or what do you mean with “smart trainers”?