Rest periods between workout sets, termed “inter-set recovery,” play a crucial role in achieving different fitness objectives. Depending on the goal, whether it’s strength, muscular endurance, or hypertrophy, the recommended rest duration varies. This article provides insights into optimizing rest times according to various training goals.
  

Key Points: 

1. “Inter-set recovery” is the time muscles use to clear metabolic waste and replenish fuel, influencing performance and results.
2. Beginners should rest for 2 to 2:30 minutes during compound exercises and 60 to 90 seconds for accessory movements, focusing on preparation for the next set.
3. For muscular endurance, 30-second rests are recommended, aiming to train muscles to clear waste quickly and condition the cardiorespiratory system efficiently.
4. Strength and power training typically requires a rest time of 3 to 5 minutes between sets to allow for maximum force generation in subsequent sets.
5. For muscle growth (hypertrophy), a 1 to 3-minute rest period between sets is advised, with recent research suggesting three minutes as the optimal duration.

Source: https://www.menshealth.com/fitness/a19540335/how-long-should-i-rest-between-sets-to-build-muscle/