The phrase "much sweat" means putting in a lot of physical or mental effort to achieve something. It expresses the idea of working hard and exerting oneself. Full definition
This percentage varies by how much sweat equity the author is willing to put into the process. (bergsland.org)
This is not an intense workout but it's pretty great for everyone who likes to keep their fitness in check but not break too much sweat. (myobuddy.com)
Think about how much sweat equity you will have to put into the item you are about to buy. (creditdonkey.com)