If you are looking to gain muscle mass, or 'bulk up', then you need to train and eat accordingly. There are four key parts to think about in order to bulk up with maximum efficiency: Fuel, Weight, Intensity and Rest.
The most effective way to build muscle is to lift hard and heavy, taxing your muscles significantly with each repetition and set that you complete. However, this must be accompanied by a suitable diet and plenty of rest, otherwise your muscles will not recover nor grow stronger. Proper nutrition is just as important as the actual training in helping you pack on muscle.
When setting out to train, you will need to increase your calorie intake and focus on eating protein-rich foods, because protein is the material used to build strong muscle. For more in-depth information on nutrition, check out our diet section.
Bodybuilding can be a strenuous activity, pushing your body to the limit. Before beginning, you should talk to a fitness instructor at the gym, make sure you know how to use the machines and weights with proper form, and consult your doctor, especially if you have any pre-existing medical conditions.
You need to eat more calories than normal if you are looking to bulk up, so that your body has enough fuel to cope with the highly demanding exercise you need to do. They must be 'clean' though, not coming from fizzy drinks and junk food, because good nutrition is key.
Foods rich in protein should be an important part of your diet, as protein is the building block for growing your muscles. You may choose to take supplements such as protein shakes too, but generally your main focus should be eating a healthy, balanced diet, which includes plenty of protein.
In order to force your muscles to grow bigger and stronger, you need to lift heavy weights. Aiming for 10 to 12 repetitions in each set, you should lift a weight that you find difficult, but are still able to lift with good form. If at any point you are unable to complete a repetition with good form, then you are either trying to lift too much weight, or trying to complete too many repetitions, and need to suitably adjust your workout as a result.
Strongly exerting your muscles in this way is what causes micro-tears in your muscle fibres. These naturally repair, and when they do they adapt to cope with the stress that caused the tears in the first place. This process is called hypertrophy, and is how muscles grow bigger, therefore leading to you bulking up.
You need to push yourself hard in order to make muscle gains. This means vigorous training, where your movements are explosive, rather than slow. Of course, you still need to be safe when you exercise, don't erratically lift weights that are too heavy, otherwise you are likely to get injured.
Endurance-based cardio training should barely feature in your training if your main goal is to build muscle. It is widely-regarded as being counter-productive to attempts to bulk up, due to it using up energy stores. However, you should still include cardio in your training, because it is important for your heart's health. Either incorporate very low-intensity exercises such as walking, to use up as little energy as possible, or do high-intensity exercises such as sprinting, which can aid muscle growth.
It is during the rest phase where your muscles grow. During training, they are actually broken down, with minuscule tears forming in the muscles. You must have adequate rest time between sessions to allow these muscles to repair themselves. This repairing process is how the muscles gain mass.
Failing to rest suitably after exercise can mean your muscles do not recover properly, resulting in a higher chance of muscle soreness or injury. Your gains may also be slower as your muscles are not given the correct amount of time needed to repair.