The Critical Body logo

The in and out bicep curl training guide

Hit your biceps from every angle with in and out curls.
Written By  James Jackson
Last Updated on 12th June 2021
A man performing an in and out bicep curl

In and out curls build and strengthen the biceps brachii by challenging your muscles from two different angles. This helps to recruit a broader range of muscle fibers and ultimately leads to better bicep development.

In this guide, you're going to learn how to do curls in an in-out fashion to add intensity to your training and muscle to your upper arms.

In and out bicep curl exercise details

  • Main Muscles: Biceps brachii
  • Secondary Muscles: Brachioradialis, brachialis, forearm flexors
  • Exercise Type: Strength
  • Exercise Mechanics: Isolation
  • Difficulty Level: Intermediate
  • Equipment Needed: Dumbbells

How to perform in and out curls

  1. Hold a pair of dumbbells by your sides with an underhand grip.
  2. Stand up straight and keep your elbows tucked in.
  3. Curl the weights toward your shoulders while keeping your elbows still.
  4. Contract your biceps at the top of the rep as they come into contact with your forearms.
  5. Lower the weights until your elbows are fully locked out.
  6. Then rotate your shoulders out so that your elbows are now pointing inward.
  7. Curl the dumbbells to your shoulders again, squeeze your biceps, and then lower the weights under control until your elbows reach full extension. That's one rep.
  8. Perform 3-5 sets of 5-12 reps.

In and out bicep curls advantages

In out bicep curls will add intensity to your training sessions and make your arms work harder than they usually would during regular curls. Best of all, you only need a simple pair of weights to enjoy these benefits.

Intense biceps pump

A man performing in and out curls for his biceps

The in and out bicep curl blasts your biceps with twice as many reps as usual. This gives your muscles plenty of time under tension and training volume to stimulate hypertrophy and make your arms grow.

But these repeated contractions also produce a powerful muscle pump because you're doing more reps per set and really shuttling a lot of blood into the biceps. This means that you get a great pump without the need to perform extra sets or any crazy intensity techniques.

That's how effective good, old-fashioned high-rep arm training protocols are for supinated curls.

So while you might not be lifting heavier during in and out curls, you're most definitely working harder and pushing closer to muscular failure than usual. In other words, you're reaping the full rewards of those challenging final sets, which, as Arnold once said, are the ones that produce the most muscle growth.

Hits all the bicep heads

The long and short head of the biceps brachii

In and out biceps curls are a great mass-builder precisely because they train both heads of the biceps.

They emphasize the long (outer) head when you curl with the dumbbells close to your sides, and they put more tension on the short (inner) head when you switch to the wider hand position.

As such, they're an excellent exercise if you want to sculpt well-rounded biceps (who doesn't?).

You can also give the in out hammer curl a go if you want to focus on overall arm development, and in particular, the brachialis and brachioradialis muscles.

It's versatile and convenient

A man doing in and out bicep curls

Got a pair of weights and a spare 5 or 10 minutes?

If so, then you can do the in out bicep curl.

You don't need access to a gym to do this exercise, and it certainly doesn't matter where you do it.

The movement is highly versatile because you can perform it standing for greater convenience. Or, you can sit on a weight bench to reduce the core stability requirement of the exercise so that you can really hone in on your biceps.

Conclusion: How to get the most from in out bicep curls

If you want to add maximum mass to your biceps, then it's a good idea to perform in and out curls at the start of your training session, when you'll naturally be at your freshest.

In this scenario, you want to perform 5-7 reps per set (one rep is equal to two normal reps, remember) so that you get plenty of time under tension while still lifting heavy enough to focus on the all-important fast-twitch muscle fibers.

Alternatively, you can do in and out biceps curls toward the back end of your session to really burn your biceps out and recruit any stubborn muscle fibers that you couldn't stimulate with your heavy sets.

Here, you want to bump up the reps (8-12 rep set) and train close to failure. Doing so will give you a great final pump and improve your mental toughness by making you wade through the uncomfortable bicep lactic acid.

James Jackson
James Jackson is a personal trainer who uses his expertise in strength and conditioning to create helpful workout tutorials that show fitness enthusiasts how to build muscle while staying safe in the gym. He draws on the latest sports science data as well as tried and tested training techniques to get the best results for his clients without them having to live in the gym.
chevron-upmenu-circlecross-circle linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram