What are the main muscle groups in the legs and how can they be effectively trained for strength and endurance?

The main muscle groups in the legs are the quadriceps, hamstrings, glutes, and calves. To effectively train these muscles for strength and endurance, exercises like squats, lunges, deadlifts, and calf raises can be performed with proper form and progressively increasing resistance. Additionally, incorporating activities like running, cycling, and hiking can help improve leg muscle endurance.