In the practice of weight training, mass gain consists of increasing the volume of the muscle and is therefore characterized by weight gain. The objective here is not only to gain muscle, but also weight: it will be necessary to combine a gain in fat mass (body fat) and a gain in lean mass (muscles).
You will therefore understand that it will be necessary to associate nutrition with training. Because increasing your mass without gaining muscle is possible, but gaining muscle in gaining fat is not!
If you’re training for muscle mass gain, choose a weight at which you reach muscle failure in the 8-12 rep range. In other words, after you warm up, you should select a load with which you can complete at least 8 reps but not more than 12. ( The weight should be between 70-85% of your max. rep )
60-90 sec rest between each sets.