To make 30 repetitions per set implies a burden rather low, which in most cases will stimulate the muscle enough to awaken. This method is discarded to gain muscle but to gain strength?
If we make a circuit where we are alternating the different muscle groups and in each season over do 30 repetitions, can help us work muscular endurance and resistance as such, but still the load will remain low.
When working with the muscle loads need a sufficient stimulus to deploy their adaptive processes as muscle gain. Anything you can do more than 25-30 reps per set is considered a low stimulus. Do 8-15 repetitions having trouble making the final, that’s another thing.
Of course, something is better than nothing and we’re not going to tell you to stop doing sets of 30 repetitions or more. An even novice often serves to learn the gesture and make sure there are no injuries to then progress slowly. But if your desire permits, put a little more weight to reach the 20-25 fatigue and tops.
As we say, do more than 30 repetitions when we consider a job in circuit if it may be more useful to work at the level of resistance, but it will have a very low impact, so it may be advisable in beginners in the first few days, but then have to go up the load.