They stretch less than sativas but still some indica strains can double in height.
A trick I use to limit stretch is to run my veg light thru the stretch. I've been using 400W HIDs so I'll either just leave the veg bulb going for the first 2 weeks of stretch then switch to my HPS or if I need more light just fire up the hps with the veg bulb until then and swap out the veg bulb for the 2nd hps for the rest of the ride.
I use a conversion bulb for veg that runs off an hps ballast so I just have to swap the hps bulb itself. A 15 yo EYE Hortilux that I bought when I started growing up here in '01. Cost a lot but worth every penny. I just bought the same type of bulb that will give me flowering light off my 1000W metal halide ballast. $170 but if it works for 15 years worth every penny.
That one is going to be running on my new light rail to do my flowering in an 8x4 grow tent we're installing next to my grow room in the basement. Gonna be really green all winter this year!