Drink BCAAs while you workout.
Consuming BCAAs during your workout replenishes your muscular energy stores and prevents catabolism (the breakdown of muscle for energy). Leucine is metabolized in your muscles for energy after the glycogen is depleted and it also signals the protein synthesis process to start. This allows longer exercise without running out of gas and feeling worn down. Combining BCAAs with a high glycemic index sugar spikes your insulin. The purpose of insulin is to transport nutrients from the bloodstream into the cells. If you eat sugar and you're not working out, guess where it goes? Fat cells. Insulin is a double edged sword, so use it appropriately.
More Fitness Tips
Pre-workout nutrition is just as important as post-workout nutrition.
Pre workout nutrition is arguably more important than post workout nutrition. Do not eat any carbs before working out, and instead consume essential amino acids (EAAs), or at the very least, BCAAs. Having a full set of free form essential amino acids in your bloodstream as you workout increases protein synthesis by 400% over baseline. Additionally, protein synthesis will not occur unless there are a full set of aminos in your bloodstream, because its rate limited by the least amount of aminos you have. So if one aminos is at 60% capacity, only up to 60% of the aminos will be used for synthesis. BCAAs will not cause protein synthesis by themselves without the other aminos, but they will prevent muscle breakdown
Want to gain muscle? Focus on strength.
Strength is king. First you get strong, then you get big. Doing 10-12 reps of curls will give you some sarcoplasmic hypertrophy (aka: fluid and increased glycogen storage), but it has a multiplier effect. If you have little or nothing there, you will make little or nothing grow. Instead, try for myofibrillar hypertrophy which is growth of the actual fibers. Reps in the range of 5-8 can accomplish this, however, you're better off doing Strong Lifts 5x5 or Starting Strength. Feel free to start customizing your workout when you can bench 225, squat 285, and deadlift 315+ for 3 sets of 5 reps
If you're trying to build muscle, take casein protein before bed.
Casein is a slow-digesting protein. When taken before bed, casein protein supports the muscle recovery process throughout the night. You can either take it in supplement form like a casein based protein powder, or by eating cottage cheese.
Use a ladder for pull-ups.
This is especially helpful if you don't have a pull-up bar. Walk inside the ladder, place a towel on one of the rungs (to protect your hands), and use it like you would use a pull-up bar.