Eccentric training involves a focused, slow muscle contraction in which the muscle lengthens.  For example, as you lower a weight from a bicep curl towards the floor the muscle simultaneously contracts and lengthens.  Eccentric contractions have been discussed in this blog for their ability to heal injured tendons, restore flexibility, and strengthen weakened muscles.  New research is looking at the comparison of this training with conventional strength training.

Authors studied untrained men and randomized to either strength training on workout machines or working with a flywheel focused on eccentric contractions.  Each group worked out 2 to 3 times per week for 5 weeks targeting the quadriceps muscle group.  The eccentric fly wheel training produced greater gains in muscle size and strength throughout the 4 quadricep muscles compared with the conventional machine despite similar workout frequency, sets, and repetitions.  This study highlights the importance of eccentric exercise for strength gains and muscle growth.