Chains can absolutely increase strength and muscle growth when used with barbell curls. They accomplish this by providing linear variable resistance (LVR), which means that as you lift the chains from the floor link by link, the weight they provide increases. This will improve your muscular strength and power because it forces you to use more fast-twitch muscle fibers. It will also place more focus on your biceps by giving you more resistance at the point in your range of motion where your biceps actually kick in—about halfway up.
To set up the chains, attach the adjustment chain (3⁄8-inch links) to the middle link of the large chain (5⁄8-inch links). Slide the adjustment chain onto the barbell as though you’re loading a plate. When you’re at the top of your range of motion, only a few links of the large chain should still be on the floor, so set the adjustment chain accordingly. Load enough total weight on the bar— chains plus plates—to limit yourself to eight to 12 reps per set, then perform barbell curls as you normally would.
Quick Tip: If you don’t have access to chains, you can reap similar LVR benefits by attaching elastic bands to the bar.
|Barbell Curl (with chains)||3||8-12|
|Barbell Curl (no chains)||2||8-12|
|Incline Dumbbell Curl||3||10-12|
|EZ-Bar Preacher Curl||3||12-15|