Random Fitness Questions

I'll answer this separately, as my main answer is what is above.

Over the years there have been differing views about what drives hypertrophy. In the past people linked the feeling of "the pump" to muscle growth, or put forward ideas about time under tension, volume and muscle damage and regrowth.

The science will maybe always be shifting, but these days it's generally thought that if your work set demonstrates that the muscles are experiencing high mechanical tension, and you sustain that and add weight or reps the next time around, in following workouts, then it's likely that - provided you are in a calorific surplus - you will grow.

What that means in practice is that if you were doing your set of curls with 10s, and they feel light, you would need to do a set where the last several reps slowed down, and you came to failure, or within a rep or two of it.

After that, it becomes a question of how many sets you would do, which remains hotly debated. There are those who would argue that only a handful of genuine sets, per week, for a body part, are enough to grow it. I think a more sensible approach might be to do something like 3 sets, particularly if you're a novice or beginner, and give yourself a greater chance of ensuring that you've performed enough productive sets.

If you did 15, 15, 8-10 with your 10s on DB curl, that would be fine... Then when repeating that workout you might shoot for 15, 15, 12-14, then 15, 15, 15 ... And then go up to 12.5kg DBs and begin again. Or you could add reps, and go for 15-20, if the 12.5kg was too much of a jump.

In theory, to your point about whether a heavier weight, performed for less reps, would be better than a lighter weight for more reps... My understanding of the thinking now is that if you're getting that high mechanical tension and training as outlined above, it doesn't matter. There are proponents for both approaches. A middle ground can usually be found, of course... Instead of 3-6 reps, or 12+ reps, you might do 6-12, for example. You'll get that mechanical tension more quickly, with a heavier weight, but some people find it easier to train smaller muscles like the rear and side delts in a higher rep range, and also safer.

As for rest, can't really go wrong with 1.5-2 minutes, as a novice or general trainee.

If I was squatting or deadlifting I might rest 3 minutes, and there are people who promote this across the board for optimal recovery and growth, but I feel like I cool down a lot, and I also don't want to spend all day in the gym. Over 6 exercises, 3 sets apiece, that extra minute's rest for each adds up.

I think if I were really going to lean into the unilateral stuff I would pick 2-3 good ones, mix of quad dominant and ham glute dominant, and then after that is a question of overall programming.

For a lower day, with a unilateral emphasis, you could do something like go heavy on the Bulgarian Split squats, just follow a strength progression for them as if they were a main barbell lift. 3 or 4 sets and just progressively overload week to week. Reps 6-10 a leg. Do your bad leg first. Then next movement single leg glute bridges or single leg deadlift, same thing. Then maybe terminal knee extensions with a band, higher reps to failure, and calf raises.

Single leg box squats are great but to me they are a regression for someone who is more debilitated. If you can do the stuff above do that instead imo.

I do like split squats in place of Bulgarian version for greater stability sometimes. Some people will do them much better and progress better.

Lunges, I feel people turn them into split squats a lot. By that I mean, whether forward or reverse, they step … settle … then split squat. There needs to be more dynamism present in a lunge whether forwards or reverse. So I like to do walking lunges with bodyweight or very light weight for quite high reps, at the end of a workout, one all out set, really driving up off the front leg. After you've done your other sets with progressive overload and very log book driven, that one set is just a finisher, could be 50-100 reps.

Step ups are good, but hard to do well, hard to resist pushing off that leg on the ground to assist yourself up. Lifting the toes off the ground helps, as does just making it more an eccentric movement and focusing on controlling the descent.

Banded single leg extensions and curls are OK but not really as useful as machine versions of those movements, you don't have the same stability and ability to progress load.

Overall, for your goal I would do plenty of unilateral work but personally I think a few movements is enough, and you could still keep in a bilateral main lift and/or machine work without losing anything.