Muscle size
More sets in the middle range of reps, each taken close to hard, for muscle that grows.
Nothing but the floor, a wall and a sturdy chair.
Four days a week: upper, lower, rest, upper, lower, then two days of rest.
Rest one and a half to two minutes between sets. Finish each set with one or two reps you could still do.
When you complete every set at the top of the range, add the smallest weight step or move to the harder version.
These routines are written for healthy adults. With an injury, a pregnancy or a medical condition, see a doctor or physiotherapist before you start.