I'm a fan of big supersets, especially for people who can only train a few days a week. If you're getting plenty of recovery time then it's okay to push harder in your sessions.
When it comes to leg training, there are a few aspects we can play with:
Normally you'd train each of these separately, either on different days or in different sets. For example, working on a heavy squat set, moving to some higher-rep work, then possibly finishing up with something more explosive.
But what if you combine all three into one amazing giant set? Well, you're in for a whole world of gains!
On your next leg day, try this combination. I apologize in advance if you need to use any stairs the day after.
Complete 5 sets of:
Take a three-minute break after set one and two, then a four-minute break after set three, and a five-minute break after set four. Trust me, you'll need it! The rest allows you to keep the intensity high during each set. (You can also attempt this workout with lighter weights and less rest. You'll get a totally different kind of stimulus.)
If it's your first time doing this workout, err on the side of caution and go a bit lighter. Later, use weights that are challenging.
Add this workout to your training once a week for 8-12 weeks. Progressively load the back squat and lunge each time and you'll really get the benefits of strength, muscle growth, endurance, and mental fortitude.
This is a character-building workout, and not everyone can get through the full five rounds. The butt DOMS after this can be laughable, so make sure you don't have to be at an important, formal event the next day.