I agree that the point is not to find a mathematical formula to predetermine your ideal level/gearing combination, however, I do think it is worthwhile to understand the effect that different level choices will have on your riding experience.
Most of the advice I’ve seen suggests being in one of the lower levels, but it seems like there might be several advantages to being in a higher level (and lower gearing to compensate) as @JGreengrass suggested. Based on my calculations in the post above, when using a higher level (Caveat: for the gearing I have, at the power outputs I am targeting—which I think are probably representative of a fair share of the SUF user base):
the power jump between gears is smaller (less likely to find yourself on the cusp of two gears)
power output is less sensitive to small changes in cadence (beneficial if your goal is to maintain a steady effort)
It would be useful to have someone double check my results, but I think they make sense:
At a lower speed you will be on an a flatter section of the resistance curve than at a higher speed
Gear changes will have less of an effect on speed in the small ring than the big ring
In a lower gear, changes in cadence will have less of an effect on speed than in a higher gear
Since, in my understanding, level mode progressively ramps resistance based on speed, it seems plausible that (in many if not all cases) the cumulative effects of those three factors could be more significant than the steeper resistance curve applied by increasing the level.
The ERG mode thing seems contentious, and I admit it is possibly dangerous/confusing advice if someone just set a static target rather than treating it as a way of actively adjusting the resistance based on RPE throughout the course of the test. Used in the way I suggested, the only downside I see is that it forces you to be very tuned into RPE because it eliminates cadence as a variable for (subconsciously) adjusting output. I agree it is not ideal to be locked into a power output in this way, but the way I’ve approached FTP testing in the past is focusing on maintaining a consistent cadence and making small adjustments to resistance throughout the test, based on RPE. I agree that ERG mode is not for everyone, but with the approach I described in this post and above the downside seems negligible.
I’m definitely not an expert in this and don’t mean to be giving misleading advice—I’m just trying to wrap my head around what’s going on, and saw that there were other people who shared my confusion/frustration! I’d love an explanation as to what I am missing, but “don’t do it, doesn’t work” isn’t enough to satisfy my curiosity
Everything that you’ve said here about Level mode is correct. The higher the level, the steeper the curve. The higher the speed, the steeper the curve.
You’re looking for 2 things when choosing a level: 1- that you can reach all the power targets in your personal power profile, and 2- that you’re in a good choice gear to be able to maintain the power you want for the long blocks without needing to shift. I would recommend choosing the lowest possible level that allows you to achieve both of these. As I mentioned earlier, one reason that you might choose a higher level is when your target power ends up at the cusp of a gear. You want to avoid shifting during the MAP and the FTP intervals.
Once you’ve figured this out, then properly pacing the efforts will be the key to your success in the test.
I know there are quite a few here who advocate for using ERG mode for the 4DP tests. And yes, it might be possible to get somewhat accurate results, but mostly, you’ll be achieving the results that you set out to achieve as you control your power targets from the beginning of the interval to the end of the interval. Making manual adjustments to power will take more effort and time than naturally adjusting cadence during the effort, in my opinion. But, the results might be good enough for you and your training.
Regarding Level Selection:
I had been looking at the large power jumps between gears as a downside (and therefore concluded that higher levels were preferable), but based on your description I can see why the bigger jumps that accompany a lower level (and correspondingly bigger gear) are actually beneficial: there is a greater latitude of potential power outputs in a single gear and normal cadence range (you have a better chance of making it through a 20 minute effort without needing to shift).
Does this also hold for dynamic efforts (i.e. for the 5 second efforts is there also a benefit to being in the lowest level possible—the trainers resistance ceiling being the limiting factor)?
Regarding Level vs ERG Mode:
The debate between level and erg mode for the 20 minute test seems to hinge on whether it is preferable to control power output by adjusting cadence or resistance (using the erg target as a proxy for resistance when maintaining a steady cadence).
Since all my previous FTP tests have been done on an indoor bike with a resistance knob (that allows very fine adjustments in resistance) rather than gears (where the jumps in resistance are comparatively large) I was seeking to emulate that setup as closely as possible, but I can see the appeal of the “hands free” approach.
As an aside, that makes me wonder whether having resistance as a dynamic variable (in level mode resistance has a positive correlation with cadence, in ERG mode there is an inverse correlation) might have a slight downside for steady state efforts. I get that in order to make sprints work without needing to shift mid-effort resistance needs to ramp progressively but, for steady state efforts, amplifying the impact changes in cadence have on power output makes maintaining a steady output slightly more difficult. That said, I doubt this has any significant effect on test results and I can understand why level mode is the best choice for the 4DP test.
In the interest of making the 4DP test as foolproof as possible—because evidently it wasn’t quite foolproof enough for me :)—I do think it would be nice to have a way to dial in the resistance on the fly (e.g. using the resistance control on the wahoo app, if the resistance control on the wahoo app allowed adjustment in finer than 5% increments) rather than needing to predetermine the optimal gearing/level combination, but I can see how this would be complicated to implement.
In lieu of that, I think there is potential for the documentation to be improved. Level selection and 4DP test approach seem much more straightforward to me knowing what I know now as a result of this discussion. It could just be including a more detailed approach to level selection, or a workout that guides you through level selection for the 4DP test (e.g. shift into the big ring and choose a gear that gives you a straight chainline. Pedal at your ideal cadence and cycle through levels until your power output is close to your ftp/expected ftp. If none of the level options gets you satisfactorily close, shift up/down a gear and try again. If you’ve chosen the correct level, you shouldn’t need to shift during the 20 minute portion of the test.).
I assume that most of us train to be better at riding a bicycle in the real world. The real world is level mode. So the test should be a a measure of the real world, and that is level mode.
In the real world we have to deal with gear shifts over terrain, so that is a good skill to learn.
Training in erg mode allows us to specify what our efforts should be so that we do not train too much or too little.
While I agree with your first point, I disagree that the test should be a measure of the real world.
The 4DP profile is primarily useful as a training metric, so I want my testing protocol to correspond as closely as possible to the conditions I’m training in (which for me is mostly ERG mode).
I do agree that there is great value to practicing how to deal with suboptimal gearing/resistance combinations (e/g/ real world riding). I just don’t think that a fitness test, that I do maybe 4 times a year, which is critical to calibrating the next 10 weeks of my training is the best place to do that.
This is kind of the feeling I’m getting, as well. All the calculations and resistance knob dialing… Yes, that should really help you >dial in< on your numbers (see what I did there) and likely help you maximize your numbers. But on the other hand, you lose out on translating it to riding outside.
Neither way is really >better< than the other. You can maximize your training, either way. But if you are planning to translate your indoor fitness back to riding outdoors, you would be better off working with your gearing while in level mode.
And also, it is not that uncommon to shift gears in the middle of the 20 minute effort. It can help prolong your effort if you change your cadence to rest your different aerobic systems. But just like anything else, it depends on the individual rider. Some riders can improve with a change of pace. Some riders get thrown off by a change of pace.
So, really, in the end, to each his own. @sf2448, I hope all the info and tips here helps you maximize your training for whatever goals you are working toward whether that’s a specific race or effort or for your general fitness.
Great discussion here! I really appreciate all the insights that have been shared, and I will definitely look into improving the documentation about Level mode in the help center in relation to Full Frontal.
As @emacdoug (Sir Evan) has stated, each person will eventually find what works best for them. I would suggest practicing. Give the sprints a try using different gears and different levels. Ideally, there’s one level that will work best for you for the entire test. If you have to be in a higher level for the sprints though, that’s ok. Just remember to change levels once those sprints are done. I don’t think you’ll hit your trainer ceiling in the lower levels unless you’re throwing down over 1000 watts on a sprint.
In the meantime, I recommend doing workouts of all kinds in level mode. It’s a bit more challenging that ERG mode, but has its own benefits. Mix it up! There are more ways to improve than just getting faster.
