"To work the legs" means to engage in exercises or activities that specifically target and strengthen the muscles in your legs, such as walking, running, cycling, or doing leg exercises like squats and lunges. Full definition
The explosive and powerful nature of jumping exercises works your leg muscles in an entirely different way than most normal slow grinding strength training moves. (truthaboutabs.com)
If running is more your thing, try taking a spin class to work your legs in a different way. (blog.booyafitness.com)
After the proper warm up sets, you can work the legs with squats. (fitnessandpower.com)