If you’ve never incorporated chains or resistance bands into your strength training, you’re missing out on some serious gains.

A study in the Journal of Strength & Conditioning Research found that variable resistance training—using chains or bands on barbells to keep the resistance changing throughout the lift—gave subjects bigger strength increases in 1RM bench than when subjects knocked out reps sans bands or chains.

That’s because those chains and bands change the point of resistance during a lift, which can help you develop more strength, power, and speed.