If you want to build muscle and if you want to do it fast, there are some scientific ways to do it. Let's find out what you can do.

Increase training volume

If you want to build more muscle and want to do it fast, you will have to increase your training volume. Training volume means your number of reps multiplied by number of sets. This is a primary determiner of hypertrophy. If you want to increase volume, you may need to go a bit low in weights, i.e. use lower weights. You may be able to use 50 to 75% of your 1RM. Which is a maximum weight you can lift for one rep. It'll be better to perform each of your lifts for 3 to 6 sets of 10 to 20 reps.

Focus more on the eccentric phase

When you lift a weight, you will get to phases-concentric and eccentric phase. When you lower your body into a squat, that is and eccentric action. When you return to standing position, that's concentric. Eccentric work will help you to build more muscle and at a faster rate because it can trigger hypertrophy.

If you want to increase the amount of eccentric effort in your workout, you can slow down the eccentric phase while performing the exercises or you can integrate eccentric only variations into your workout routine. Both ways will work for you. How can you do that? Let's take the example of squat. While performing a squat, you can lower your body to the floor and end the exercise there to make it eccentric only. When you are performing eccentric only exercises, you will need to increase the weight you are using substantially.

Reduce between set rest intervals

If you want to build muscle and do it faster, you will need to make some changes to your rest intervals. You will need to reduce the intervals between two sets. Keep it to 30 to 90 seconds. If you want hypertrophy, or more muscle building, rest periods of 30 to 90 seconds are better for you because they encourage a quick release in muscle building hormones. They will help you by releasing testosterone and human growth hormone. It is important to fatigue your muscles if you really want to build muscles and do it faster. Fatiguing your muscles is a prerequisite for hypertrophy.

Eat more protein

If you really want to build muscle and also want to do it fast, you will need to eat more protein in your diet. When exercise, your muscles are broken down and protein builds them back up. When you're exercising heavy and exercising more, you will need more protein. There are several muscle building foods which will help you to build more muscle by providing you with more protein. More protein will improve your recovery. According to scientific research done in the University of Stirling, for optimal protein growth, you need to consume 0.25 to 0.30 g of protein per kilogram bodyweight per meal. It means you will need 3 to 4 eggs, cup of Greek yogurt one scoop of protein powder. You'll also need to understand that you will need calorie surpluses and not calorie deficits.

References 1. 7 Seconds To A Perfect Body
2. Weight and muscle gain
3. Muscle growth and exercise