IFBB

This phrase is short for the International Federation of Bodybuilders, which is the largest sports federation created way back in 1946 by Joe and Ben Weider. This organization has more than 120 member countries, and focuses on bodybuilding as an international sport. Using its federation establishment this body keeps track of the competitions held in each country and directly forsees and conducts professional and beginnner tournaments for men and women. 

INSERTION

This is simply known as the easily moveable section of any muscle. 

INSULIN

This is a particular hormone excreted by the pancreas and aids in the speeding up the metabolism of carbohydrates. The primary function of insulin is to decide whether the carbohydrates are to be utilized for energy purposes, storage within the muscular cells (glycogen), or for storing the carbohydrates in the form of fats (in case of an excess). 

INTENSITY

This refers to the level of hard work and dedication put in to every set of a work out. The higher the level of pressure put on a working muscle the more quickly it will result in a hypertrophy increase. There ar emany ways in which the level of intensity within an exercise can be increased. The most common ones include using heavier weights in the same time frame, reducing the duration of breaks after each set while performing each exercise with a fixed amount of weights and lastly, increase the number of sets with a particular given weight. 

IN THE ZONE

This is an informal phrase for being tired and lost during any workout regime. It is often known as being spaced out as well.

ISOLATION EXERCISE

Highly different from a normal exercise, this one focuses on laying stress upon a single muscle group or a one muscle even, separating it from the overall body. These exercises are perfect for giving shape to one particular muscle. For instance, squats are intended for working the thigh muscle and if compared to an isolation exercise, leg extensions would fit in. 

ISOMETRIC CONTRACTION

A concept in exercising or working out, when the muscles have an inherent tension developing, but don't lengthen or shorten accordingly. 

JUDGING ROUNDS

This term is used as a reference for the judging system applicable for all bodybuilders in competitions. The internationally accepted and implemented technique by the IFBB is judging all builders in three separate rounds. A final round is kept as well, but for only the top five shortlisted competitors post the initial rounds of judging. Round One, is rather laid back, and observes the builders from the front, back and either sides as well. Round Two progresses to become more formal and builders are judged in group format. The highlights of this round are the seven fixed poses for the builders, which help the judges in making their decision. In Round Three, the builders are given the freedom to pose freely and show their routines paired with personally chosen music. Overall, this method of judging results in a fair decision process and tries to eliminate the possibility of any unfairness.

JUICE

This is usually an informal term used to refer to the consumption of anabolic steroids. For instance, if someone is taking them, it is said that they are on the juice (i.e. anabolic steroids).

JUST ONE MORE REP

Another informal phrase that is used by a trainer during a set. This phrase is used to encourage more physical activity.