In weightlifting, most lifters perform isometric variations of movements. They perform these isometrics many times with weights far heavier than they can actually lift in the normal variation. Isometric holds can be used to overload the system and prepare the body for the stimulus of a heavier weight. They can also be used to build up superior stability in certain positions. A great exercise which can be used for this purpose is front rack holds. These can be used to increase core stability and upper back stability. When performing this exercise, it is important to remember the hold should resemble perfect front squat technique at the top. The lifter should be in a solid rack position as if about to lower themselves into a front squat. This means elbows up, core tight, and chest up. Also, there should be no rounding of the back in any way. If rounding of the back occurs, the weight is too heavy. Most lifters will be able to start with around 110% of their best front squat triple for a 30 second hold. Most lifters will progress quickly in this exercise. As long as form does not break the weight can be moved up. Many International level lifters have been seen doing 3-4 times their bodyweight with this exercise, so the possibilities here are fairly endless! Disclaimer: Be careful if you feel like you are going to pass out and the lift is best performed in a cage rack.