Hi,
I’m new to training with this application and was wondering if I should be using erg mode or change it to standard? The workouts are set by default using ERG mode and I’m really usure what to do. I want to be able to sustain my power outdoors and it feels like ERG mode might not be the right approach as its simulated.
Any thoughts or suggestions?
You can use whatever mode you’d like but personally I prefer ERG because it doesn’t allow you to let up during intervals, if you start losing leg speed you’re still expected to produce the same wattage, which ERG will make sure you do. Using standard when your leg speed falls off will result in lower watts. That said, standard is closer to reality than ERG. ERG also helps you not to overshoot watt targets.
I think the higher the intensity, the less erg more works well, especially for ‘max’ or sprint efforts.
For lower intensity efforts I really like it. This keeps me at the right effort level when watching movies, etc. For the trainers I have used (previously kickr, now H3) the erg adjustments are slow enough that I don’t think it is altering the power during an individual pedal stroke to a meaningful degree. If you quickly increase your cadence, you can overshoot the power by a significant margin, and if intra-pedal stroke adjustments were being aggressively made I think this overshoot would be much more minor. Note that this will vary between trainers, and ones like the Tacx Neo series may be different, as there is no flywheel. The steadier your cadence, the less of a difference erg vs non-erg will make.
If you have your keyboard/mouse/phone close by and can adjust the erg level during intervals it does make getting the intensity correctly set easier. I think this is important especially for harder intervals.
You will find that there are a lot of strongly held opinions/preferences regarding erg vs non-erg, so be prepared to make up your own mind 
Personal preference.
If you want to give ERG a good effort, this is required viewing to understand how it does and doesn’t work.
For best results, focus on your cadence and let the system control power. There are more considerations with respect to gearing, but that may not be worth discussion if you prefer Resistance mode.
Erg’s great for watching a movie or cycling crits on youtube.
In a hard workout, the pro to having resistance mode is the trainer doesn’t need to forecast high intensity efforts and lag behind when power is supposed to change. Since you are entirely in control, you also have the opportunity to regret all of the decisions that led to a 3 minute repeat VO2 max workout. Delay the start by 2 seconds, and carry the effort after the interval ends by those 2 seconds.
Power is power, but non-Erg introduces both mental and physical aspects of making indoor training more like outside. With Erg you can easily find yourself sticking with a single cadence. Yes its possible to vary cadence with Erg. If you want to make indoor more like outdoor, then no better option than riding a smart trainer in sim mode (Zwift, RGT, Rouvy, Bkool, etc) and running the workout on bike computer. Or to replicate riding on flat terrain, simply use slope mode and your bike computer. Or if you want to do the work and multitask, then Erg is your best option.
I use erg mode but am inclined to stop for the more intense intervals.
Reason being, when a hard/short interval gets too much, the erg mode forces me shut up shop and stop as my cadence is forced too low. Without erg mode I’d be able to finish the interval but with my power just lowering throughout the interval. My heart rate would still remain in the desired zone.
Erg all day long
Essential that specificity is maintained and in harder efforts it’s far too easy to drift off target.
Erg also allows you to focus on technique and efficiency 
Started with erg and currently I never use it. I prefer standard because it’s more fun and I need to focus on holding my power. The fact you can ease the power is additional stimulus for me to not to do this and holding it no matter what - like on the road. Not to mention that I feel way better outside after using standard than after erg mode - the transition is easier. And I have also observed that I use my muscles a little bit different to generate power between standard and erg. Not to mention how different power feel when I have to generate it “from the top” and it’s not pushed “from the bottom” like in erg.
So it’s a matter of individual preference but I see a lot of benefits for me personally with standard.
Always ERG, then I can watch stuff on the pad without having to worry about maintaining power output too much
Erg for sweetspot and endurance, resistance mode for sprints.
I didn’t like erg when I first started on here, because it takes a while to get used to. I like it for high cadence drills and smooth pedalling.
I used ERG for my first two years of TR, but this summer I switched to standard on my Hammer. I find that my legs are less sore the day after a workout, which is a bonus for me.