Hislop and Perrine (1967) described isometric exercise as muscular contractions against a load which is fixed or immovable or is simply too much to overcome. Two German physiologists (Muller and Hettinger, 1954) performed a study which claimed that one six second isometric contraction at two-thirds maximum performed once each day for five days was sufficient for 5% strength gains per week. This received a disproportionate amount of publicity from which it would appear that the medical community has never recovered.
