In science and in fitness humans are split into three distinct body types. These are Ectomorphs, Mesomorphs and Endomorphs. We tend to be a mix, Ecto-mesomorph, Endo-mesomorph. Understanding your own individual body type will make it easier for you to design your own individual plan. To keep things simple, I will describe the three types and give examples of sports stars who fit them.
Ectomorph: A typical Ectomorph is tall and naturally lean with long limbs and a slim waste. They will find it harder to build muscle and strength then a Mesomorph and an Endomorph. They also have a faster metabolism, meaning they seem to be able to eat what they want without gaining weight. A typical Ectomorph will benefit more from shorter strength workouts as they will not have the strength endurance of a Mesomorph. As they tend to have a faster metabolism they will not need to perform as much cardio-vascular exercise to burn bodyfat as an Endomorph would. A good example of an Ectomorph would be Sir Andy Murray.
Mesomorph: A typical Mesomorph has an athletic physique consisting of wide shoulders and a narrow waste. Gains in muscle and strength come easily to the Mesomorph so they will respond positively to most types of training. As well as gaining muscle size easily a Mesomorph also burns excess bodyfat quickly making it for them to get in contest shape for bodybuilding. A good example of a Mesomorph would be Mike Tyson.
Endomorphs: An Endomorph is the opposite of an Ectomorph. The natural physique of an Endomorph has both wide shoulders and a wide waste. Endomorphs tend to gain weight easily. Like a Mesomorph an Endomorph will gain muscle and strength easily but as they have a slower metabolism they will gain excess bodyfat easily. This means that for their strength and size gains to show an Endomorph would need to perform more cardio-vascular exercise then an Ectomorph. They would also need to be more disciplined with their nutrition. Endomorphs tend to suit sports such as the Hammer throw, Olympic wrestling and Olympic weight lifting. The sadly deceased wrestler John Tenta, better known as Earthquake is a good example of an Endomorph. Extremely strong but carrying excess bodyfat, especially around his belly.
As I stated in the beginning nobody fits exactly into each category. We are all a mix of the three. I would be classified as an Ecto-mesomorph and get the most benefit from shorter more intense gym workouts. Understanding your own body type will make it easier for you to design your own workouts, however consistent training and nutrition will help you more than simply relying on your genetics.