Although everyone is different, scientists have managed to categorise three main body types: Ectomorph, Mesomorph and Endomorph.EctomorphsEctomorphic people are generally quite lean and struggle to build muscle mass. Regardless of their diet, their body stays very thin and maintain a week muscular profile. For this body type, you need to do longer sets (about 15 reps) and have longer rest periods between sets (3-5 minutes). This technique is very specific to ectomorphs, due to a large number of slow contracting muscle fibres. To gain muscle mass, ectomorphs must avoid cardio and take care of their diet.MesomorphsSome people are just born with perfect everything. Mesomorphs fall into this category. Considered to have the perfect body type, these people are naturally muscular.These people don’t need to work out every day of the week; in fact, 2-3 days a week are enough. A little bit of cardio can sometimes be useful and working alone is highly recommended to start seeing even better results. EndomorphsOften smaller and slightly stocky, endomorphs easily gain weight. By weight, we mean fat, not muscle mass. Their slow metabolism makes it difficult to lose fat.Circuit training and high-intensity sessions are recommended for this body type. A HIIT session, for example, is perfect for burning fat and gaining muscle mass. It is also essential to have good nutrition and avoid fatty foods. The most important thing here is not to try and attach yourself to one category or another. If you have a fitness program and relentless motivation, you will start to see the results.