Original sentence: His system was flawed in that there was no method of measuring progression; users were not motivated by measurable progress as assessment of increases in strength was subjective and lacked an empirical means of demonstrating progress.Isometrics fell out of favor as it was discovered that many of the principal advocates were using steroids to enhance their gains
Edited sentence: His system was flawed in that there was no method of measuring progression; users were not motivated by measurable progress as assessment of increases in strength subjective and lacked an empirical means of demonstrating progress.Unfortunately, isometrics fell out of favor as it was discovered that many of the principal advocates were using steroids to enhance their gains