Arm training machines: the bicep and tricep guide

Arm training machines earn their place because they hold tension across the full range of a curl or extension, which a barbell or dumbbell simply cannot do at both ends of the rep. On our floor I coach members to build arms with a preacher curl machine, a seated bicep curl machine, cable stations, and heavy dumbbells, all working together rather than competing.

I'm Dr Matt Walley, and I co-founded Inception Gym Christchurch with my wife Elise in 2022. I spend a lot of time on the floor watching people train arms, and the same pattern comes up again: plenty of pressing and pulling, almost no direct, deliberate arm work. This guide fixes that.

Key takeaways

• Direct arm work gives a stimulus your compound presses and pulls miss, and machines deliver constant tension the free weights can't.
• The preacher curl machine is the single best bicep isolator on our floor because it kills the ability to cheat.
• Long-head triceps grow from overhead extensions, not pushdowns, and most flat-looking arms are simply undertrained overhead.
• Use machines and free weights together. It is not one or the other.
• Small muscles still need protein and calories to grow, so the nutrition has to match the training.

Why arm machines belong in your programme

The arms are one of the most visible muscle groups on the body and one of the most commonly under-trained for direct work. A lot of lifters assume that heavy pressing and pulling cover the biceps and triceps. Those lifts contribute, but direct arm work gives a different stimulus and, in my experience coaching members, meaningfully better arm development.

The case for machine-based arm training comes down to tension and honesty. Free weight arm exercises like the barbell curl or the dumbbell kickback have awkward resistance curves. The barbell curl has near-zero resistance at the very bottom and again near the top. A well-designed arm machine holds tension across the whole range, which means more total mechanical tension per set.

At Inception Gym in Addington, the arm lineup covers a preacher curl machine, a seated bicep curl machine, cable stations with a full attachment set for curls, pushdowns and overhead extensions, a Smith machine for close-grip pressing, and dumbbells up to 70kg. That sits inside a floor of 92-plus machines, 43 of them plate-loaded. This guide walks each arm option, what it builds, and how to mix machines with free weights.

If someone tells me their arms won't grow, nine times out of ten the problem isn't genetics, it's that they have never trained an arm to honest failure without their torso doing half the lift.

Bicep anatomy

The biceps brachii has two heads: the long head (outer portion, builds the peak) and the short head (inner portion, builds width). Both flex the elbow and supinate the forearm.

Brachialis. Sits under the bicep. When developed, it pushes the bicep up and adds thickness. Responds best to neutral or pronated grip curling.

Brachioradialis. The forearm muscle that helps with elbow flexion at a neutral grip. Built with hammer curl variations.

For full arm development you need work that hits the long head (supinated grip, shoulder-width or wider), the short head (closer grip, slightly internally rotated), and the brachialis (neutral or pronated grip).

Tricep anatomy

The triceps brachii has three heads: long, lateral, and medial.

Long head. The largest of the three, running down the back of the upper arm. It's the only head that crosses the shoulder joint, so it's most involved when the arm is overhead. Responds to arms-elevated work.

Lateral head. Most visible from the side, forms the horseshoe on the outer tricep. Best targeted with close-grip pressing and pushdowns.

Medial head. The innermost head, often called the workhorse. Active in nearly every tricep exercise and hard to isolate on its own.

Effective tricep training hits all three, which means pushdowns (lateral and medial) and overhead extensions (long head). Roughly two thirds of the upper arm is triceps, so if arm size is your goal, this is where the size lives.

What are the best bicep machines?

The best bicep machines are the preacher curl machine and the seated bicep curl machine, backed up by the cable stations for constant tension. Here is how I'd use each.

Preacher curl machine

The preacher curl is one of the best bicep isolation tools we own. The pad locks the upper arm at an angle that stops shoulder recruitment and keeps tension on the bicep at both the bottom and the top of the rep.

Targets. Biceps brachii, with extra emphasis on the lower bicep and the brachialis when you use a neutral or slightly pronated grip.

Why the preacher position matters. Fixing the upper arm against the pad kills the ability to swing the torso or shrug the shoulders to help. The bicep does the work. It also loads the bicep in a stretched position at the bottom, which the current research increasingly links to better hypertrophy.

How to use it. Adjust the seat so that when you grip the handles your upper arms rest flat on the pad and the crease of your elbow lines up with the edge of the pad. Curl through the full range and control the descent. Aim for a 2 to 3 second eccentric.

Programming. 3 to 4 sets of 10 to 12 reps. Don't rush. The slow eccentric is the point.

Seated bicep curl machine

The seated curl gives a guided arc with constant cam tension throughout the rep. The arm hangs more vertically than on the preacher, which shifts the resistance curve.

Targets. Biceps brachii, emphasising the mid-range and the peak contraction.

Programming. Slots in well as a second bicep exercise after the preacher curl. 3 sets of 12 to 15 reps.

Cable bicep curl (low pulley)

The cable low pulley curl gives you continuous tension that dumbbells can't match. At the top of a dumbbell curl the resistance drops to near zero because the weight sits right above the elbow. The cable keeps horizontal tension throughout.

Variations.

• Straight bar: standard supinated grip, hits both heads
• EZ bar: slightly supinated, easier on the wrists
• Rope: hands separate and supinate at the top for a stronger peak contraction
• Single handle: unilateral, removes strong-side compensation

Programming. Great as a finisher or in supersets. 3 sets of 12 to 20 reps.

Concentration curl (dumbbells)

Not a machine, but worth mentioning because our dumbbell rack runs up to 70kg. That makes heavy concentration curls realistic for advanced lifters chasing peak.

Targets. The long head of the bicep in particular, which sets the height of the peak.

What are the best tricep machines?

For triceps, the cable pushdown, the overhead extension, and close-grip pressing cover all three heads. The overhead work is the piece most people skip and it's the one that changes an arm.

Tricep pushdown (cable, high pulley)

The pushdown is the most common cable tricep exercise and one of the most effective. The high pulley extends the elbow against resistance pulling upward, which loads the tricep through a clean extension pattern.

Targets. All three heads, with slightly more lateral and medial involvement depending on the attachment.

Attachments.

• Straight bar: standard, pronated grip
• EZ bar: slightly supinated at the bottom, easier on the wrists
• Rope: wrists rotate and flare at the bottom for maximum contraction and more lateral head
• V-bar: similar to the straight bar with a friendlier wrist angle
• Single handle: unilateral

How to use it. Face the cable, elbows tucked. Elbows stay fixed; only the forearm moves. Push down to full extension and feel the tricep contract hard. Control the return to about 90 degrees of elbow flexion.

Programming. 3 to 4 sets of 12 to 15 reps. Rope pushdowns with a full flare at the bottom are particularly good for the lateral head.

Overhead tricep extension (machine or cable)

Overhead changes the game for triceps. With the arms overhead the long head is fully stretched, and the research suggests that position produces meaningfully better long head growth than pushdown-only training.

Targets. The long head of the tricep.

How to use it (cable version). Set the pulley low and use a rope. Face away from the stack, grip the rope overhead, and extend forward and overhead. Keep your elbows pointing forward, not flaring wide, and extend to a straight-arm position.

Why it matters. If your triceps look flat from behind, you're almost certainly not training the long head enough. Overhead extension work fills in the back of the arm in a way pushdowns simply can't.

Programming. 3 to 4 sets of 10 to 15 reps.

Tricep kickback (machine or cable)

The kickback isolates the lateral and medial heads in a hinged position. The machine or cable version beats the dumbbell version because it keeps tension at the contracted end of the range, where the dumbbell version drops it off a cliff.

Programming. 3 sets of 12 to 15 reps. Works well as a final tricep exercise.

Close-grip bench press (barbell or Smith machine)

Not a machine exercise, but a staple of tricep training. A shoulder-width or slightly narrower grip on a bench press shifts emphasis from the chest to the triceps. The Smith machine version on our floor is a safe alternative that keeps the bar path locked, which is handy when you're pushing heavy without a spotter.

Targets. All three tricep heads, and it takes heavier loading than any isolation exercise.

Programming. If close-grip pressing is in your session, do it first while you're fresh. 4 sets of 6 to 10 reps.

Do machines replace free weights for arms?

No. This is probably the most common arm question I get on the floor, and the answer is that machines and free weights sit alongside each other. They solve different problems.

Free weights are good for.

• Natural wrist and elbow rotation through the rep
• More stabiliser recruitment
• Movements like dumbbell hammer curls for the brachialis and brachioradialis that machines don't replicate as cleanly

Machines are good for.

• Constant or increasing tension through the full range
• Pushing sets close to failure without form falling apart from instability
• Fixed paths so you can focus on the contraction rather than balance

A good arm programme uses both: heavy barbell or dumbbell curls for strength and neural drive, and machine and cable work for volume, constant tension, and finishing. If you want to go deeper on that trade-off, I wrote a whole piece on free weights versus machines.

Programming arm training

Here is a session I'm happy to put in front of most members. It trains biceps and triceps together and puts the heaviest, most fatiguing work first.

1. Close-grip bench press (triceps first, while fresh): 4 sets of 8 reps
2. Preacher curl machine: 4 sets of 10 reps
3. Overhead cable tricep extension: 3 sets of 12 reps
4. Cable bicep curl (rope): 3 sets of 15 reps
5. Tricep pushdown (rope): 3 sets of 15 reps
6. Seated bicep curl machine: 3 sets of 15 reps

Arms as a session vs accessory work. Plenty of our members train arms as a standalone session once a week, and plenty just add arm volume to the end of chest or back days. Both work. Total weekly volume matters far more than how you split it, which is exactly what I get into in the training volume guide.

Weekly volume targets.

• Biceps: 10 to 20 sets per week for most gym members
• Triceps: 10 to 20 sets per week, remembering that heavy pressing already delivers a chunk of tricep volume

One thing I'll add from years of watching people train: arms are the muscle group most often trained with ego and least often trained with intent. Slow the eccentric down, stop swinging, and take the set genuinely close to failure, and you'll grow with less weight than you think.

Nutrition and arm growth

Building visible arm mass needs enough protein to support muscle protein synthesis and enough calories to support growth. The biceps and triceps are relatively small muscles, and they won't grow in isolation from your overall nutrition. I've watched people add real size to their arms just by fixing their protein intake and staying consistent, without changing a single exercise.

Members can use our on-site Supplement Solutions store stocking the full Inception Labs range at member pricing. Creapure-sourced creatine monohydrate remains one of the best-supported supplements for strength on curls and presses, and it's an easy, cheap win to bolt onto an arm programme.

For a personalised approach, Inception Nutrition runs PhD-led coaching that builds a nutrition and supplement protocol around your training and your body composition data. Our members get free body composition scans, so you can actually see whether the arm work is putting muscle on rather than guessing in the mirror.

Try the arm setup at Inception Gym

The arm machine selection is best judged in person. Our free trial gives you 24 hours of full access: the preacher curl machine, every cable attachment, the Smith machine, and the full 70kg dumbbell rack. Come in, run a real arm session, and feel the difference constant tension makes.

Related guides: the preacher curl machine guide, the specialty bars guide.

If you're ready to make it permanent, have a look at the full equipment inventory or compare membership plans. We're at Tower Junction, 65 Blenheim Road, Addington, with 3,000-plus free car parks and 24-hour access, and we hold a 5.0 rating across 1,000+ Google reviews. I'd back our arm floor against any gym in Christchurch.