ISOLATION EXERCISES
ISOLATION MOVEMENTS,
such as biceps curls or triceps skull-crushers, target specific areas, pushing those muscles to grow by limiting the involvement of other muscles. If your goals are aesthetic, isolation moves should have a prime place in your routine. In this respect, dumbbells are superior – especially when it comes to the nuance of biceps curls.
Your biceps have two main responsibilities. You know the first: they flex your arm at the elbow. But they also drive another motion called supination, turning your palm upward towards the ceiling.
If you grab a kettlebell and do a biceps curl, yes, you’ll still have to flex your arm at the elbow. But the physics of the dumbbell, with one weight on either side of
the handle, forces you to think about supination. Samuel, who has possibly done the odd curl or two, is unequivocal: “Working to keep a dumbbell perfectly balanced as you curl up is a biceps-growing mechanical challenge that you can only garner from a dumbbell.”
When an honest-togoodness arm pump is required, the DB is the OG.