Pre-ex

Pre-exhaustion or pre-ex is a strength training protocol invented by bodybuilding writer Bob Kennedy and popularized by Arthur Jones and Mike Mentzer. In theory, muscle development will always be incomplete with standard movements, because the large muscle group will outlast the smaller supporting muscles. As an example, the triceps will become exhausted prior to the chest or shoulder muscles on any given pressing movement. The proposed solution is to "pre-exhaust" the larger muscle, in order to given the smaller muscles a temporary advantage in strength.