Looking for expert insights on "Build Me Up" plan


This may get a little long, so I won’t blame anyone if they don’t want to read it, but if you want to help a relative newbie out then read on…

I’m fairly new to cycling for fitness as I bought my bike toward the end of this past summer. I’m also new to Zwift and have been using it for about a week and a half. I’m using a Tacx Flux S smart trainer.
Prior to tonight, my Zwift sessions consisted of choosing a world and a route, and then riding it – while trying to push myself at least a little bit.

This evening I decided to try a training plan. After browsing what was available I decided to try the “Build me up” plan. It was a new experience, that much is certain. It started me out on a warmup for 5 minutes where it told me a certain wattage to shoot for. I pedaled slower and slower until I dropped down to that wattage. I was on one of the smaller gears in the back and the big gear in the front, so it didn’t feel like much effort. A couple minutes in, it told me I should bring my cadence up to 90 (I think I was around 60 at the most). I couldn’t get there on the gear I was on, so I started moving up to the bigger gears in the back. I ended up on the third biggest gear and was able to hit the 90 cadence. It was much less resistance than I’m used to, but I’m trusting that this plan knows what it’s doing.

So here’s what I’m curious about. The workout was called Halvfems and it had me moving around between 60, 85, and 90 rpms (plus a push to 100 rpm at the end), and between 90, 125, and 145 watts. I know that Zwift has some idea of what my FTP is because it told me after one of my rides that it had gone up a couple of points. I don’t recall seeing any place to tell the training plan what my FTP was, so should I assume that the numbers it has me shooting for are based on what Zwift knows my FTP to be? Also, early on in the ride, it had me going at 125 watts and 90 rpm and it told me that I was about to go up to 145 watts and still 90 rpm. I was thinking, “Ok, I’ll probably have to shift to the next smaller gear in the back to get more watts at the same RPM.” But as soon as I passed through the little arch to show I was moving to the next phase, my wattage was suddenly around 145 even though it felt like I was pedaling at the same effort. Is Zwift telling my smart trainer to increase resistance between these two phases? It didn’t feel any harder to pedal at 90 rpm, but maybe it’s such a small change to go up 20 watts that I just don’t notice it?

I guess I’m wondering if any of the seasoned vets out there might see anything in what I’ve written that would tip them off if I’m doing anything in a less than optimal way. I’m especially curious about if and how I should use my gears for this plan. Once I found the gear that let me get up to 90 rpm, I stayed in that gear the entire time. It felt like Zwift and the smart trainer were adjusting based on the gear I was in, so I didn’t want to change it. Is being in the big gear in the front and one of the bigger (but not the biggest) gears in the back the way to go? I only have a big and small gear in the front, so nothing in between.

For the record, while I may be new to training on a bike, I have been a runner for a good decade, so I’m somewhat accustomed to the natural build up of a training plan. I just started to burn out on running and let myself get a bit out of shape, so now I’m trying to use the bike to get some level of fitness back. :slight_smile:

Thanks for your time if you read this far! I see that there is another “Build Me Up” thread out there, but I wasn’t sure if it was better to tack onto that or make a new one, so I made a new one…

Hi Marc,
Welcome to the world of Zwift.

You are asking for expert help sorry to say I’m hardly and expert but I might be able to shed some light. I have been on Zwift for 14 months, level 36, completed all of the challenges, ridden every route at least once, climbed the Alpe lots. I started riding bikes 2 years ago and I’m old. Tonight I finished week 8 of the Build Me Up workout the same you are doing.

First thing when you log into zwift check your public profile it should have your ftp there. You are correct, the workout takes your ftp and uses that to determine the wattage it wants you to do as you progress through the intervals.There is also a bias control where you can tone down what the workout expects from you, see the up/down arrows at the bottom of the box at the left of the screen which shows the intervals you are doing for that session, the one that has the stars on the completed intervals.

When you do a workout in Zwift you are in what is called ERG mode. With a smart trainer that means you are supposed to ride at the desired cadence and the trainer will adjust the resistance accordingly. So you shouldn’t in theory have to shift at all. For me at least, I do a little bit of shifting because when the workout goes from 110 rpm to 70 rpm i end up with something like 40 watts. But still the shifting should be minimal.What works best for me is I use my small chain ring 40 tooth and leave it there. I make small adjustments using the read cog. My set up has my watts jumping around a bit which is annoying.

I used a dumb trainer before I got a smart trainer and it was the opposite. There I always used to big chain ring, now i only use it in free rides. Some of the intervals in Build Me Up have you riding at 110 rpm. You are not going to do that on the big chainring.

I don’t know if this is any help to you. My advice is give it some time and experiment but know that ERG mode is designed to limit shifting gears.

For me personally, this workout plan has increased my average cadence by about 10 rpm. It is my first workout plan in the 14 months I’ve been using Zwift. It has also improved my ability to tolerate riding at above my threshold. Up to this week I was not sure it was helping me at all but now I’m starting to think I will see a gain. If nothing else my quads are getting bigger lol! I rode by the way over 6000 miles in 2020 but the workout seems to be improving my performance but time will tell.


Thomas’ description is quite good, covers most of what I’d offer as well. I’m a 35+ year endurance cyclist in the Colorado mountains, so lots of experience pushing myself, but new to Zwift. I’m 5 weeks into the Build Me Up plan.

As Thomas says, ERG mode is having your trainer hold the specified Watts no matter how you are applying the power. Shift to a higher gear so the RPM goes down, the trainer will increase the resistance accordingly. Stay in the same gear and raise your cadence, the trainer will reduce the resistance to hold the wattage. Changing gears has only a couple seconds of effect then it is normalized by the trainer. No need to do much shifting. If you stay in the same gear for the whole workout you will find that when told to spin up, say from 65 to 90, initially you’ll feel a good bit of resistance until the trainer notices the change in speed then it will adapt real quickly and the pedalling will become easier and you’ll get up to 90 in about 10 seconds. When asked to spin down, the wattage drops very low for a few seconds because you are basically not putting any power into the pedals. You can try to smooth this out with a shift as Thomas notes, it’s your call. Sometimes I do shift, sometimes I don’t. But it should only be 1 or 2 gears, if you do more than that you are going to be chasing the trainer.

As for FTP, having the right FTP is critically important. To high and the workout is too hard for you to complete. Too low and it’s easier than it should be and you are not getting the benefits intended from the workout. Given you don’t know your FTP, it is probably a good idea to do an FTP test. Find that in the list of workouts. That will determine your FTP and set it for you in Zwift. Then the training plan will be just right for you. If you find the workouts are too easy still, you can step it up/down with the arrows as Thomas describes. Other places that the same arrow functionality exists is on the Companion App in the workout page, and if on a PC when you hit the up arrow key there set of buttons that appear at the bottom of the screen have an up and a down arrow. You can bias a workout up to 10% up or down. I’d suggest not doing that at the beginning of the workout. You’ll quickly see that the same interval set that felt easy at the start of the workout is much tougher at the end, that’s fatigue and that’s what the workout is trying to reach.

You can easily find your FTP in game by going to the Settings screen that has your name, age, weight, etc… One of the fields in there is FTP. There you can see what Zwift has set (it may be right or not, let the FTP test dictate that) and you can change it there as well.

Build Me Up is a solid plan, it’s going to push you (if FTP is set right) and you will grow as a cyclist. Enjoy it.

Happy Zwifting


Thanks for the input. It was really helpful.

Today was interesting and raised another question. I was doing a free ride in Watopia and I chose the Road to Sky route. I was (foolishly) thinking “10.7 miles. Not too long since I have things to do tonight.” Well, I stopped after about 45 minutes and just past the “11” marker on the Alpe du Zwift. I’ll have to try it again when I can finish, but I have homework to work on for my night class!

Anyway, the interesting thing was that it told me my FTP went up from 154 to 181! I do feel I was doing pretty well since I was staying in a bigger gear in the back for much of the climb and was able to pass people more than people were passing me. So will my training plan compensate for this new FTP value? Or would I have to manually change it?

It should adjust automatically. In the training menu on the workout tab is another area you can check what your ftp is set at and change it up and down.

You should probably do an ftp test and restart the plan on Monday. Always start plans on Monday.

Read this article too.

@MarcinMN One more tool to help you avoid that surprise you got on the Road to Sky route. You can see all the details of a route on both ZwiftInsider under Routes Maps and Details, or on ZwiftHub. They each have their pros and cons for looking up routes.

ZwiftInsider provides a lot more information on each route, but you have to click on each one individually, you can’t see them next to each other.

ZwiftHub provides primarily the distance and profile visually very easy so you can see many routes real quick (and you can expand a route to see where on the map it goes) but does not have all the detail.

Depending on which you are looking for, use the best tool for you. I find ZwiftHub to be great as I can see distances and profiles so quickly. With this you can see that Road to Sky goes cranking uphill.

As a side note, Alpe du Zwift is a replica of the famous Alpe d’ Huez in France. A literal copy of the slopes and curves, with Watopia created scenery. Go to YouTube and check out some of the videos about it. One nice one shows how the Zwift team went about making it and the graphics animation involved in Zwift courses. I found it pretty interesting.

Hi Marc,

With an ftp jump of 30 watts you should see a rather large increase in the difficulty in the individual workout load. Not knowing anything about you except you are a runner I would guess that an ftp of 150 is low.

Zwift will calculate ftp based on a best 20 minute effort which you achieved on your partial climb on the ADZ. One of the reasons I have avoided riding the Alpe since I started the Build Me Up is because I’m afraid that I will get an ftp boost and while we have the option to not accept it, I rather wait another 3 weeks to finish the program to see where my ftp is now. It’s sort of a mental thing. Also, weeks 10 & 11 in the program have 5 workouts each which really doesn’t allow for much recovery, none if we do extra rides outside of the plan.

I think it is hard to do a 12 week plan on Zwift if for no other reason than having to spend most if not all of your trainer time in the plan which leaves very little time for anything else, social rides or races. I would say that I’m glad that I put in the effort but really looking forward to completing it!

I had my first hitch for this plan yesterday when the session was all about pedaling technique. I don’t have the kind of shoes/pedals that you clip into. My bike did come with those strappy things on the pedals that you can slide your foot into, but I don’t currently have them on the pedals. I took them off because:

  1. I could see myself running into something while I’m focused on trying to get my toes into them while riding down the road.
  2. I tipped over on the ride home from the bike shop the first time because I forgot that my feet were strapped to the pedals. lol

I’ve considered putting the straps back on for this plan. I guess I at least can’t tip over while the bike is attached to a smart trainer. Though I can see myself being challenged by the task of getting my foot hooked back in while not stopping the pedaling motion entirely. I guess I almost have to do it if it’s going to ask me to pedal with only one foot from time to time. Last night I just tried to focus on having a nice smooth motion with both of my not-attached-to-the-pedals feet.

This winter time on the trainer would probably be an ideal time to get accustomed to clipping in and out of pedals, but I’ve had an expensive couple months so I don’t really want to upgrade my pedals and shoes at the moment…

I rode for years in athletic shoes and I used the pedal straps too.
Switching to proper cycling shoes was one of the most noticeable improvements I ever made.
The improved transfer of power is quite noticeable.
I realized how much power that cushion in my shoe was absorbing.

I too fell over , more than once, when I couldn’t get my feet out of those straps.
I have also fallen over with my new clip less pedals…
usually its while stopped in the parking lot with one foot still clipped and I lean the wrong way.

The decades old toe-strap concept is way out of date, in part because of the issues with getting in and out of them. Clip in pedals (humorously enough they are called clipless, because they came about to replace toe-clips) are far easier to use and far safer. As Tim comments, the improvement from riding shoes is quite noticable in itself, add clipless pedals and you’ll really notice it because you can use the whole pedal stroke.

I’d suggest investing in riding shoes and clipless pedals now while you are on the trainer. By the time you get to riding outside you will find unclilpping will be natural. There are many different styles of pedals and their associated cleats. Shimiano SPD are by far the most common, but like all things there are tradeoffs. Do a little research to see what style of pedal and cleat match your use model best and go invest.