In order to gain muscle you need to eat more calories than what are needed to maintain your current weight. This means you will be in a caloric surplus by around 5-10%. Along with gaining muscle, you will also gain some fat. How much fat you gain will depend on your body. The most common way to approach a bulk (especially from a females perspective) is to lean bulk. Doing a lean bulk allows you to gain muscle while gaining as little fat as possible.
In order to do a lean bulk, you need to work out the calories that are needed for bulking for your body. If you need help with your calculations, you can fill out the form here, or if you are confident enough to work it out yourself, you can do that here. You want to input all your information into the calculator and select ‘Bulking – Cautious 5%’. I always recommend starting out with 5% to see how your body responds before increasing calories.
If you have been cutting weight and trying to lose fat, then it is a good idea to increase your calories slowly (by 50-70 per week) until you reach your 5% surplus calories (this is done the same way as a reverse diet). The reason for the slow increase in calories is to avoid too much weight gain which can come with a sudden increase in calories. Once you reach your 5% bulking calories, you want to monitor your weight and results each week. If you are maintaining your weight at a 5% bulk, then you can increase it up to 10%.
When it comes to your macros for bulking, I usually choose around 1g protein per lb of body weight and .40-.45g fat per lb of body weight. You may need to play around with the numbers to find what works best for you. You can eat 6 small meals or 3 large meals, so long as you stick to your macros each day. You want to make hitting your protein a priority and allow a bit of leeway on carbs and fats (up to 20g under or over your carb and fat goal). You will also need to recalculate your macros if your weight or activity level changes. If you are new to tracking your macros, I highly recommend using myfitnesspal.
When it comes to exercise, you MUST lift weights. Weight training needs to be the core of your workouts (4-6 days per week). If you eat in a surplus and don’t lift weights you will just gain body fat. Lifting (and lifting heavy) is a must. You are not going to gain muscle by picking up 5lb weights. How many sets and reps you do is up to you, but when training to gain muscle, most people use heavy weights with low reps (6-10) and longer rest periods (2-3 minutes). Cardio isn’t a huge part of bulking, and most females choose to do no cardio while trying to gain muscle (this is because cardio is known to burn muscle). If you want to add cardio, HIIT 2-3x per week is best.
You want to gain weight when trying to gain muscle. That is the point. In order to gain muscle, you need to gain weight. You want to aim to gain 200-500g per week. If you are gaining more than that you may be gaining too much fat. If you aren’t gaining at all you will need to increase your calories.
Another way to lean bulk is to eat at a 5-10% surplus on training days and eat at maintenance on rest days. You may want to try this if you think you are gaining too much fat.