How to disable touch in Run activity?

I must be overlooking something, I have touch disabled, but lately during running I noticed that touch was active, and I can't find how to disable it.
The manual says: "To enable or disable the touchscreen during general use or activities, hold Menu symbol, select System > Touch, and select an option." which I did, but is there a separate option somewhere for touch during activities?
It is raining a lot these days, and the screen changes every time when my wet sleeve touches the watch and when I wipe raindrops off. It is a bit unsettling.