So, what are the benefits of EBR to eccentrics? Because the magnitude of EBR is primarily a function of its elastic properties and not the force of gravity, there is also opportunity for much greater eccentric velocities and accelerations. This is because the band is extended at the end of the concentric and start of the eccentric phases.

You can see the benefits of EBR graphically on the slide. Two supine squat movements were compared with (EBR) and without elastic resistance (free weight resistance – FWR). EBR vastus lateralis EMG activity and sled mean velocity were found to be significantly greater throughout the entire eccentric phase compared to the FWR squat. Similarly, in terms of the table all comparisons between FWR and EBR were found to differ significantly. Most noteworthy were the higher velocities and shorter contraction durations (DOC) and time to peak velocities (TPV) in the EBR loading.

More to come on these benefits in terms of stretch-shorten cycle movement?

Reference: Cronin, J., McNair, P.J., Marshall, R.N. The effects of bungy weight training on muscle function and performance. Journal of Sports Sciences, (2003), 21, 59-71