For most lifters, arm day is built around the holy trinity of biceps training: barbell curls, dumbbell curls and, occasionally, cable curls. It works – but it doesn’t make you immune to plateaus.
According to Dr Mike Israetel, the issue isn’t effort, but variety. As he explains in a YouTube video: ‘In my training for many years, I only really knew a few types of curls – barbell, dumbbell, cable – and that was kind of it.’
His solution is what he calls a ‘curl codex’ – a framework designed to turn a handful of exercises into dozens of effective variations. ‘By recombining these, you’re going to be able to come up with, use, and grow from dozens and dozens of different kinds of curls,’ he says. ‘Which means the variation will never run out, and you’ll be able to train consistently and build bigger biceps.’
How to Vary Your Curls
Instead of searching for the ‘best’ curl, the idea is to build movements using four key variables:
1. Implement
This refers to the equipment you use. ‘You can do barbell curls, EZ-bar curls, dumbbell curls or cable curls. You can also use dual cables, which allow you to move your arms behind your body in a way standard setups don’t,’ says Israetel. ‘And lastly, there are curl machines.’
2. Angle
Angle is arguably the most important variable. Changing it alters where the biceps are loaded most.
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‘You can lean forward, as in a spider curl. You can stay upright – either standing or seated, which both count as variation,’ he says.
Israetel also recommends incline curls at different angles, along with lying curls and, for maximum stretch, decline curls.
3. Setup
You can vary whether you train both arms at once or one at a time.
‘In most cases, you can train bilaterally – both arms together – or unilaterally,’ he explains.
‘Unilateral work can improve contraction, mind-muscle connection and force output. But it’s less stable and takes longer, since you’re training one arm at a time.’ Both approaches have value.
4. Grip
Grip changes which muscles are emphasised and how effectively the biceps are trained.
‘One function of the biceps is forearm flexion, but another key role is supination – rotating the palm upwards,’ he says. ‘If you grip the outer edges of a dumbbell, it shifts the load and allows for resisted supination, which can make for a great biceps exercise.’
Neutral grip variations, such as hammer curls, are another option. ‘Then there’s the overhand grip – the reverse curl. It doesn’t heavily target the biceps, but it does train the forearms and other elbow flexors.’
The Takeaway
Combine these variables and you unlock a wide range of curl variations. Rotating them over time can help maintain progress while reducing joint stress and training fatigue.
Israetel notes that some setups tend to outperform others – particularly those that load the biceps in a stretched position.
‘We’re talking about behind-the-back dual cable curls, low incline curls, lying curls and decline curls,’ he says.
By contrast, spider curls – where you lean forward – prioritise peak contraction rather than stretch under tension, and tend to be less effective overall.
He also points out that hammer curls, while useful, replicate positions already used in most pulling movements.
‘Almost all rows, pull-ups and pulldowns use that same neutral grip,’ he says.
His advice: pick one variable from each category and combine them into a variation that suits you.
‘You can’t do overhand curls on a V-shaped curl machine – you’ll wreck your wrists,’ he says. ‘Choose options that feel good, improve your mind-muscle connection and help you progress.’
