Arms day is about to get a whole lot more effective thanks to ‘centimeter workouts’

The arms section of spin class is the biggest mindf**k in the fitness world. Because: How can a series of different curl variations with three-pound weights burn out your arms to the point of complete exhaustion in a matter of less than five minutes? The answer is all thanks to micromovements.

By making teeny, tiny tweaks when you do curls via “centimeter workouts”—those where you move your arms just a smidge and feel a whole lot of difference—you’re able to target entirely different subsets of muscles in your arms (fun fact: your biceps are actually made up of three different muscles!). “By moving your arms a small amount during curls, it changes the angles you are working, thereby activating different parts of your muscles you might not otherwise use,” says RYDE instructor Kaitlin Parker, who coached my arms to the point of exhaustion this morning. “It also shifts your focus a bit, so instead of focusing just on squeezing your biceps for example, a different angle or pace might make you focus also on activating your triceps on the way down.”

In addition to moving the angle of your arms, you can also benefit from switching up the resistance you’re facing, which is why trainers so frequently ask you to switch from full extension of a move to a series of pulses and back again. “Small adjustments force you to use your muscles differently which tires them out,” says Parker.  “The more variation in the workout, the better, because it keeps your muscles guessing, especially when you play with pace and extension.”

And you don’t have to subject yourself to a spin class in order to reap the benefits of these micro moves. Steal Parker’s go-to series, below.

• 8 bicep curls, palms facing up
• 8 bicep curls, palms facing up, arms out at a 45-degree angle
• 8 bicep pulses, palms facing up, elbows held at 90-degrees
• 8 hammer curls, palms facing in
• 8 bicep pulses, palms facing down, elbows held at 90-degrees
• Repeat as many times as you can for three to four minutes total, and your arms will be on fire.

If you want to add even more movements into the mix, play with pulses versus full extensions, and move your arms out to the side at different angles. The options are endless, and you will definitely be feeling it tomorrow.

This nine-move dumbbell workout works every muscle in your upper body. And while you know you should be strengthening your arms, you may not know about another important muscle you should be working: your breathing muscles.