Optimal Training Volume For Muscle Growth
We have been told to finish our workout in 45 minutes, when our workout is time-oriented then we may have to perform fewer sets. When we say fewer then what does it mean? Well, it depends on a lot of other things too, for example, rest periods, kind of training, etc. So how many sets per day will give you the best muscle stimuli when your end goal is to build muscle, no matter your gender.!
Experiments have been conducted, and the results are shocking! Schoenfeld has always amazed us with his findings, in an experiment he found out that the group that performed higher training volume gained more muscle mass and strength. In his experiment the volumes very relatively low when compared with people/enthusiasts performing in local or branded gyms. He concluded, that muscle hypertrophy follows a dose-response relationship, with increasingly greater gains achieved with higher training volumes.
Matheus Barbalho had some crazy findings, we performed 45 sets per muscle group per week, and found that 5 sets - 10 sets per muscle group per week are sufficient in gaining muscle size and strength. Many experiments, researchers, and coaches have explained the importance of training volume when it comes to muscle building, and we know yes it is the biggest contributor to your muscle building. Barbalho and colleagues also quoted that the muscle-building process starts to deteriorate after 10 sets per muscle group per week. For him, the sweetest spot to build a decent physique is 5-10 sets per muscle group per week.

Many other studies confirm that groups that performed higher training volumes built more muscle mass and strength. There is a study where individuals performed 32 sets per muscle group per week, they built more muscles than other groups who performed lower training volumes than 32.
LET'S DISCUSS THIS IN DETAIL:
1- You have got these muscle groups to train, chest, biceps, back, triceps, shoulders, Quads, Hamstrings, Calves, Abdominal, etc. This equates to 288 sets per week! THIS IS HUMONGOUS! UNREAL and STUPID!
2- Athletes who performed 32 sets are made to perform in the fields and arena! We have our lives, our stress, finances, and other struggles. We know many of us don't care much, they just want to build muscles. But these athletes' activities, eating patterns, and hydration was monitored at microscopic levels. WE DON'T HAVE SUCH A LIFE?!!

So what do we do? We have it sorted for you?! Bodybuilding and fitness have more gray areas than any other industry. So let's keep it a win-win for most of us:
1- Plan for 10-15 sets per muscle group per week, with adequate rest between sets!
2- When we say aqequate rest then we mean rest intervals >= 3 minutes.
3- Increase training frequency, because if you are going to split your routine in multiples then your training volume will also go up! NO STRATEGY IS NEEDED!
NOW GO AND GRIND!
REFERENCES:
https://pubmed.ncbi.nlm.nih.gov/30153194/
https://pubmed.ncbi.nlm.nih.gov/30779716/
https://journals.lww.com/nsca-scj/fulltext/2020/10000/body_recomposition
__can_trained_individuals_build.3.aspx