Chains and bands build no more strength than plain weights
Across 17 pooled trials, lifters using elastic bands or chains gained the same maximal strength and power as those lifting conventional weights. The one clear edge ran the other way: plain weights produced larger lower-body strength gains when sets used more repetitions.
For you: No reason to buy bands or chains for the sake of strength gains: plain weights get you to the same place, so train with whichever kit you enjoy.
What it shows: About as solid as training research gets: results pooled from 17 trials covering 491 healthy adults aged 18 to 37, most of them men, so young lifters are well covered while older or highly trained ones are not. One wrinkle: plain weights edged ahead for lower-body strength when sets ran to more repetitions.Meta-analysis · J Sci Med Sport