Many will understand that more repetitions and more sets is an excellent means of progressive overload. Typically, you will begin by incrementally increasing the amount of repetitions you can perform of a certain movement until fatigued.
See a basic idea of increased repetitions over the course of a 1-month timeframe below;
Week 1 - Sets and Reps = 3 x 8 = 24 Cumulative Repetitions
Week 2 - Sets and Reps = 3 x 10 = 30 Cumulative Repetitions
Week 3- Sets and Reps = 3 x 12 = 36 Cumulative Repetitions
Week 4- Sets and Reps = 3 x 15 = 45 Cumulative Repetitions
See a basic idea of increased sets over the course of a 1-month timeframe below;
Week 1 - Sets and Reps = 1 x 15 = 15 Cumulative Repetitions
Week 2 - Sets and Reps = 2 x 12 = 24 Cumulative Repetitions
Week 3- Sets and Reps = 3 x 10 = 30 Cumulative Repetitions
Week 4- Sets and Reps = 4 x 8 = 32 Cumulative Repetitions
However, for most, there comes a point in time when increasing the reps and sets becomes too excessive and unenjoyable to maintain long term and can also put more emphasis on muscular endurance over muscle size and strength.
This is when we look at the concept of increased training frequency to provide an additional stimulus for improvements in muscular size and strength.
For example, increasing the number of days performing our exercise therapy from 3 days to 4 days per week. It may be a good idea to build up the additional day of exercise slowly and safely, instead of adding another full day of resistance training abruptly and performing too much extra volume in 1 week.