Zwift is an immensely popular game that allows user to simulate outdoor riding while grinding away on the trainer. It’s opened doors for cyclists and allows them to participate in everything from races to group rides. But what about using Zwift as the sole method for training?
First let’s talk about some of the pros and cons of using workout mode and using free ride mode. In workout mode, you are given set power levels for certain durations that you have to follow as you ride through the Zwift environment. If you have an ERG trainer, your resistance will be determined by the workout or interval intensity and not by the riding environment. This means that hills will not feel more or less difficult and you will not be able to coast. If your interval is set for 250w your trainer will keep you at 250w for however long the interval is set to last. It becomes much more like using a dumb trainer in the sense that you will not be able to ‘feel’ the changes in terrain but your rider will still react to the course. Your avatar will slow down going up hill and speed up on down hills. With a dumb trainer, the only difference is that you must control the amount of effort you put into the pedals to make sure you hit the power targets.
In ERG mode if you decrease your cadence significantly or abruptly and/or stop riding without pressing the pause button, Zwift thinks you are having trouble maintaining the effort and will boot you out of ERG mode. This means you have to ride the rest of that interval in slope mode. The same rules apply with respect to the environment, your trainer will not react to ascents or descents. It will act exactly as a dumb trainer would. It is now up to you to maintain the target power. Some trainers ERG mode will re-engage if you ride for a minute or so at the target power but not all trainers are compatible with this feature. ERG will re-engage at the beginning of the next interval.
The UI for the workout creator is very intuitive but there are still some nuances with it. Different power zones are colour coded. Zone 3 (or tempo) is green, for example, and it will automatically set your power output to a target power within that zone when you drop a green block into the workout creator. By default it uses the bottom end of the zone. Here’s where it gets tricky. In the UI, it displays the target power in watts but in the background Zwift is using % of FTP to run its calculations. You have to be mindful when you make changes to the target power with respect to your FTP. For example, let’s say you drop a tempo block into the workout timeline and the default target power is 240w. You decide that you’d rather do your tempo effort at the top of the zone, which is around 260w so you change the target power to 260w. Before saving the workout you see that your FTP is set 15w too low so you adjust it. Even though you set the target power to 260w, Zwift will recalculate that target power to reflect your FTP change. So if your FTP was set at 300w, 260w is 86% of of 300. When you update your FTP to 315, it corrects the target power to 270w to keep the target wattage at 86% of FTP. When you enter the game, you might find yourself surprised that suddenly the program wants you to work at 10w higher than you planned. The obvious thing to do is make sure your FTP is correct before building a workout.
Everyone who has been on Zwift knows what free riding is. On an ERG trainer the resistance changes to simulate climbs, descents, flats, and drafting. When using free ride mode to complete a workout you have to shift gears to match the effort level required of the terrain. It’s not difficult but it will mean more fluctuations in effort and cadence, just as you would experience out on the road. But keep in mind that anything the game simulates for you, i.e. climbs at low cadences, you can simulate yourself, especially if you have an ERG trainer. If you set your power output to 200w and bring your cadence down to 60rpm, there is nothing different about the ‘feel’ or the effort than there would be doing a 200w effort up boxhill in the London course. Do you need Zwift to simulate the changes in terrain you would experience outside? No. Absolutely not. But to really get a good benefit from the game, you have to think of the different terrain features as opportunities to do intervals, just as you would outside. Inside of doing trying to ride 90 minutes at tempo at 95rpm and have to fiddle with gear changes and downhills and fighting the Zwift environment, incorporate the terrain in to the ride. Use boxhill as a 7-12minute threshold effort with the backside descent as your recovery then ride tempo back into town once you’re back on the flat. Do this for all the courses in Zwift. Have a look at the terrain maps on the Zwiftblog and use your experience riding to find 3, 5, 10, 20, and 30min stretches and assign your intensities based on the duration of those segments. Do your VO2 max efforts on the 3 and 5 minute segments. threshold and sweet spot on the 10 and 20, etc.
Just like riding out on the road, riding with other people is a good way to keep you honest and keep you motivated. It’s much more motivating to keep going through a hard effort if your pride and ego won’t allow you to be dropped by the person you’re riding with. Group rides are fun because you get the advantage of being able to shelter in the pack and recover without having to kick the ride altogether. Riders doing long zone 2 efforts will often find themselves losing motivation long before their legs give out. Riding in groups is a good way to stay in the game (literally and figuratively) and finish the ride.
Zwift races are fun too and they can offer a good dose of high intensity training. Remember that race fitness, especially if you’re a racer or planning to peak for a summer event, isn’t the greatest thing to be building in the winter. Do the ZTR races but stay within your limit with respect to intensity. There’s nothing at stake in a Zwift race so don’t get caught up trying to win or pushing yourself to the brink trying to stay with the group. Ride until you get a good workout or until you’ve hit your target TSS or duration for that day and then drop out of the race. Lots of elite racers do this on the road in summer but they are going to race upwards of 30-60 times in a season and don’t have to carefully schedule their lives around the race. So be like a pro when you can. If a 20 minute threshold effort is what you’ve got on the training plan, join the race, take a flyer from the start and try to hold off the pack for 20minutes. Once you get your 20minutes done, drop the race. Or keep going and just sit in.
If Zwift racing is the only kind of racing you’ll do then sure, give it everything in every race. Do race specific workouts outside of races to get better at racing. But if summer is your jam, remember the long goal and don’t let your ego derail your training by doing sprint intervals 3 times a week in February because you want to be a Zwift champion.
Putting it All Together
Building a solid weekly training cycle on Zwift can be fun and really give your training a good boost if you’re the type who needs more than just a graph on a screen. But make sure that the bulk of your training is targeted effort driven riding. Don’t just ride Zwift everyday because it’s there. Find a group ride on the weekend (or during the week if you have the time) that allows you to do some long endurance rides with a few tempo efforts. Put together a solid sweet spot and threshold workout in the workout creator to do twice a week. Fill another slot with some free ride hill climbing efforts (base your effort on the duration it will take to do the climb) and join a short race. I highly recommend combining efforts. Do a 60 min climbing workout then take part in 30minutes of hard racing.
Zwift is fun but remember that it’s just a game. What really counts is your effort and your own fitness. Your best competitor in Zwift is you. Getting the KOM jersey isn’t as important as improving your own best time on the KOM. That’s what really counts and the improvement in your performance is what people are going to notice when you get out on the roads come spring. They won’t remember or care about the time you held the KOM jersey on Zwift for an hour in February.