In plyometrics is it based on a eccentric stretch OR contraction followed by a concentric contraction? i guess my real question is what is the difference between eccentric contractions and stretching if there is any? confused between the two terms stretch and contraction when used with eccentric! help much appreciated!
Plyometrics is characterised by a rapid eccentric contraction (lengethening) followed by a rapid concentric contraction (shortenting). This cause the 'spring re-coil' of the muscle which is why plyometrics is valued as a good power trainer.
In terms of stretching, yes you have eccentric stretches but these are done far slower. Stretches need to be done slow to allow the muscle fibres to fully extend .
So pretty much just remember:
Plyometrics eccentric contraction = Rapid/Fast/Short Duration
Stretching eccentric contraction = Slow/Sustained/Long duration