A short guide to muscles
Muscles are the stringy mass of fibres that contract and expand to make your joints move and stop you crumpling in a saggy heap on the floor. You’ve got between 600 and 700 muscles in your body altogether.

Not all muscle fibres are created equal. Some are made up of ‘slow-twitch’ fibres that are laced with lots of capillaries to supply them with oxygen, and are mainly used in aerobic, endurance activities such as running.

Other muscles are made up of ‘fast-twitch’ fibres which have fewer capillaries and convert stored glycogen into glucose to fuel explosive, anaerobic movements such as jumping or lifting heavy weights. It’s these fast-twitch fibres that have the greatest potential for growth, which is why power sportsmen such as sprinters and weightlifters tend to be bulkier than endurance athletes such as marathon runners.

The number of fast-twitch and slow-twitch fibres you have is determined at birth by your genes. This explains why some people pack on muscle easily while others struggle to add weight. But even classic ectomorph (skinny) guys can bulk up with the right training and nutrition – it will just take a bit more work.

The muscle grows when you put sufficient stress on it to create microscopic tears in the muscle fibres which, if you give them sufficient rest and amino acids from protein-rich foods, will heal bigger and stronger than they were before. This process is known as hypertrophy. Once the muscle has healed, it is more resistant to stress, so you need to attack it with bigger weights in order to repeat the damage/repair process that will make it grow again. That’s why you need to subject your muscles to ‘progressive overload’ or, in other words, keep lifting bigger and bigger weights.

Pecs broken down
The main job of the chest muscles – the pectorals or ‘pecs’ – is to push your arms in front of you. They are also used when bringing your arms down from above you. The pectoralis major is a large muscle that attaches to your collarbone, breastbone and ribs. Although it is a single muscle, most experienced weight trainers divide the chest into three portions: upper, middle and lower.

Any chest exercise will work the entire pec muscle, but by varying the angle of attack, by doing incline or decline bench presses, for example, it is possible to target the upper or lower portions of the muscle and build a bigger chest.

Three classic moves to help you get a bigger chest:
Bench press - This is the classic chest-building move and a standard test of upper-body strength. It is also a great all-over mass-builder because it requires a large number of muscle fibres to perform, which triggers the body’s natural growth hormone response.

T-press-up – Add a dynamic rotational element to the plain old press-up to turn it into move that will help you get a bigger chest and torch fat, too. The trick is to make the exercise fast and fluid, using your core muscles to control the movement.

Cable crossover flye - By using a cable machine, you keep the tension on your muscles constant throughout the move. Your midriff will also get a workout keeping your torso stable against the cables’ resistance.