If youre using TCP/IP then your switches shoulsd be able to cope with being up to 100m apart, however I’ve found that much more than 70m and you get lots of errors which then slows the connection down. Make sure your cabling is in good condition. If you have a long length without the need to split the line out to different users then a signal booster may be a better bet as its designed to do this job. If you run cabling outside then make sure its in conduit to protect it from the weather (both sunlight and rain), otherwise in a couple of years you’ll find you get tons of impossible to find errors either when its very hot or a couple of days after rain!
If you can, try to run a central backbone of switches with high speed links, then run single cables to each user from backbone switches, rather than running several tiers of switches from switches as it makes a better network.