Some things to consider when using bands/chains in your training:
-Bands are better at training reactive power /strength as when used properly they will activate the powerful stretch shorten cycle (SSC). To elaborate when quickly stretched a muscle will store a large amount of elastic energy in some structures (mainly the tendon). This creates a stretch reflex like an elastic band which then increases the force of the following muscle contraction. To be trained correctly the transition between stretching and contraction must be immediate for the most benefit, otherwise the energy is dissipated within the muscle. You must reverse the weight as powerfully as you can as soon as the eccentric/lowering phase of the movement is completed. Training the SSC is vital for powerful sprinting, jumping, throwing etc – all these movement are preceded by a stretch of the muscle. Plyometrics are another method for training the SSC.
-Due to the quicker loading compared to chain bands can be quite hard on the joints so be careful if you have shoulder/elbow injuries