Charles Poliquin trained expert strength coaches Ashleigh Quint and Ryan Faehnle introduce the ISO-Dynamic Training Series. Episode 1 focuses on both the upper and lower back. Isometric contractions are used to train the back specifically when to many people use momentum, heaving weights and they are not targeting the muscles of the back, in their weakest position. This specific ISO-Dynamic back workout will make you feel weak today, but that is so you grow stronger over time.