Pairing smaller muscle groups like biceps with legs can work well because bicep training doesn't significantly fatigue the body.

The total amount of working sets is by far the biggest determinant of how much muscle you're going to grow per session. You can do anywhere from one set to as many as 12 to 15 sets for a muscle group in a session, but if you exceed your maximum recoverable volume, you risk reaching junk volume where your nervous system is too fatigued to recruit muscle fibers effectively.

To determine if you're doing the right amount of volume, consider how many sessions you have per muscle group in a week. If you're training your chest twice a week and feel fully recovered before your next session, you can increase the number of sets you do.

For strength training, a regimen of three to five compound exercises for three to five repetitions per set, with three to five minutes of rest, performed three to five times a week is effective. This approach allows for significant strength gains without excessive soreness.

Most people should aim for 5 to 15 sets of resistance exercise per week per muscle group to offset declines in muscle strength.

You should rest between sets until your cardiovascular system is mostly recovered, you feel strong again, and your synergist muscles are not limiting your performance. If your target muscle is ready to perform at least five repetitions, then it's time to go again.

A good muscular endurance training protocol involves performing three to five sets of 12 to 100 repetitions, focusing on exercises like pushups and pull-ups to build the ability to perform work repeatedly over time, with concentric movements and 30 to 180 seconds of rest in between.

Training to failure can lead to greater muscle growth but also increases fatigue significantly, so it's important to balance intensity and recovery. Going from some number of reps in reserve all the way to failure in a single mesocycle is a good practice for many, but not required; you can go two or three reps in reserve as long as you do enough sets to achieve close to ideal hypertrophy outcomes.

To improve strength, you should perform anywhere from two to 20 sets per week, with five sets being sufficient to maintain muscle mass.