Erg mode and Watts?

workout/ bike help - hope this makes sense!!
So I’m new to this whole cycling thing let along indoors I have a trax thing that should do everything.
I’m sticking to the “bump on board workouts” so I know I’m safe/still get a challenge as 16 weeks pregnant.
In a few of them it wants a higher cadence but much lower watts… I have it on erg mode so supposedly the bike/machine should work with me and it does on the ones I keep it about 65rpm through the whole workout it sorts the resistance out of me. But as soon as I’m in a workout it wants me to change cadence it goes to pot eg one is 2 mins at 90rpm but 50 watts and then 2 mins at 60 with 85 watts eland repeat. On the fast bit I can’t get my watts below 110 (112 is my supposed FTP although this is just on weight) but on the 60 bit it’s fine. I have kept at the higher rpm for over a min so you would hope it had time to adjust?
Any wise ideas please? I don’t touch the gears but it’s in a high gear could it be this? Or just avoid this workout lol?


A lot of people find that ERG mode works best if you use the small chainring up front, and pick a gear roughly in the middle of the cassette (giving you a nice straight chainline). Could be worth a try to see if that helps.


I second Steve’s suggestion. And in case of intervals where you have to significantly increase power (for short periods 10-30 seconds) I find it best to change to the big front ring literally 1 second before the interval begins. Otherwise the trainer won’t catch up with power in time.

And working those short intervals with ERG off doesn’t work for me either because I’ll always overpower it…