Table of Contents
- Key Takeaways (Read This First)
- What Exactly Are Long and Short Biceps?
- The Finger Test—Which One Do You Have?
- Deep Dive into Short Biceps
- Deep Dive into Long Biceps
- The Ultimate Training Guide (For Everyone)
- The Best Exercises for SHORT Biceps
- The Best Exercises for LONG Biceps
- Bicep Myths Busted
- Photography and Posing Tricks
Have you ever looked at your arm while flexing in the mirror and wondered why your bicep looks a certain way? Maybe you have noticed a large gap between your muscle and your elbow, or perhaps your muscle seems to stretch all the way down to your forearm without much of a peak. You might have seen bodybuilders with arms that look like mountain peaks and others with arms that look like thick, solid blocks. This is the great debate of long biceps versus short biceps, and if you are confused about which one you have or how to train it, you are in the right place.
Key Takeaways (Read This First)
- You can’t change your biceps “insertion,” but you can absolutely change how big and defined your arms look through smart training.
- The popular “finger test” is a practical visual check, not a medical diagnosis, and it works best when you’re lean enough to see/feel the muscle edge.
- Short biceps often shine with a higher peak, while long biceps often look fuller and thicker even when relaxed.
- To “fill the gap,” you don’t lengthen the biceps; you build the brachialis and brachioradialis to add lower-arm thickness and better lines.
- For a better peak (especially with long biceps), prioritize long-head-biased curls that put the arm behind the torso (incline curls) and emphasize supination and hard top-end squeezes.
- The biggest driver of arm growth is progressive overload + good technique + consistent weekly volume, not finding a “secret” exercise.
What Exactly Are Long and Short Biceps?
Before we start lifting heavy weights, we need to understand what is happening under the skin. When we talk about "long" or "short" biceps, we aren't talking about the length of your actual arm bone. You could have really long arms and still have "short biceps," or short arms with "long biceps." It sounds confusing, but it is actually quite simple when you look at how the muscle is built.
The Muscle and the Tendon
Think of your bicep muscle like a piece of steak. At both ends of that steak, there are tough, rope-like cords called tendons. These tendons are what attach the muscle to your bones.
- The Muscle Belly: This is the red, fleshy part that contracts, gets pumped, and grows bigger when you work out.
- The Tendon: This is the white, fibrous cord that connects the muscle to the bone. Tendons don't grow or get bigger like muscles do; they are just the anchors.
The difference between a long bicep and a short bicep is simply a ratio game. It is a battle for space on your upper arm bone (the humerus) between the muscle belly and the tendon.
The Short Bicep
Imagine your upper arm bone. In a "short bicep," the muscle belly ends high up on the arm, far away from the elbow. Because the muscle stops early, the tendon has to be very long to reach down and connect to the forearm.
- Visual Cues: When you flex, you will see a noticeable gap between the bulk of your muscle and your elbow crease.
- The Look: Because the muscle is squeezed into a smaller space high up on the arm, it tends to grow upward rather than outward. This creates a high, dramatic peak. It looks like a ball or an egg sitting on your arm.
The Long Bicep
Now imagine that same upper arm bone. In a "long bicep," the muscle belly stretches much further down, ending very close to the elbow. Because the muscle takes up so much space, the tendon is very short.
- Visual Cues: When you flex, there is almost no gap. The muscle seems to flow directly into the forearm.
- The Look: Because the muscle is spread out over a longer area, it doesn't pile up as high. These arms tend to look fuller and thicker, like a deeply inflated football, but they often lack that sharp, high mountain peak.
It Is All About Genetics
Here is the most important thing to remember right now: You cannot change your insertion point. This is determined by your DNA, just like your eye color or your height. No amount of stretching, special creams, or specific exercises will physically move the spot where your tendon attaches to your bone.
If you were born with short biceps, you will always have that gap. If you were born with long biceps, you will always have that fullness. But don't let this discourage you! Knowing this is actually freeing. It means you can stop wasting time trying to change the unchangeable and focus 100% of your energy on maximizing what you do have. Both types can look incredible if developed properly.
The Two Heads of the Beast
The word "biceps" literally means "two heads." Your bicep isn't just one slab of meat; it is two separate strips of muscle that run side-by-side.
- The Long Head: This sits on the outside of your arm. This is the part that is mostly responsible for the peak. When you look at a bodybuilder doing a back double bicep pose, the bump you see is the long head.
- The Short Head: This sits on the inside of your arm (closest to your chest). This head gives your arm its width and thickness.
Key idea: You can’t move where the tendon attaches, but you can bias training toward the long head or short head by changing arm position and grip style.
The Finger Test—Which One Do You Have?
You don't need an expensive MRI or a doctor's visit to figure out your bicep type. There is a very simple, tried-and-true method used by gym-goers all over the world. It is called the Finger Test, and you can do it right now while you are reading this.
Step-by-Step Guide to the Finger Test
Step 1: Get in Position
Stand up or sit down comfortably. Bend one of your arms at a 90-degree angle, like the letter "L."
Step 2: Flex Hard
Squeeze your bicep as hard as you can. Make a classic muscle pose. Turn your wrist so your pinky finger is twisting slightly toward your face (this is called supination, and it helps flex the muscle fully).
Step 3: Locate the Gap
Look at the inside of your elbow, right where the crease is. Now look at where the round part of your bicep muscle ends. Do you see a space between the muscle and the elbow crease? That space is where your tendon is.
Step 4: The Measurement
Take the fingers of your other hand and try to fit them into that gap. Lay your fingers flat against your arm, perpendicular to the bone. See how many fingers you can fit comfortably between the end of your bicep muscle and the crease of your elbow.
Interpreting Your Results
Result A: The Short Bicep (2 or More Fingers)
If you can fit two, three, or even four fingers into that gap, you have short biceps.
- What this means: Your muscle belly ends high on the arm. You possess the "High Insertion" genetics.
- Your Superpower: You have the potential for a massive, high peak. Your arms will likely look very impressive when flexed because of that dramatic shape.
- Your Challenge: Your arms might look a bit thinner near the elbow, especially when they are relaxed or straight.
Result B: The Long Bicep (Zero Fingers)
If you cannot fit any fingers in the gap, if your muscle touches your elbow crease or is very close to it, you have long biceps.
- What this means: Your muscle belly extends all the way down. You possess the "low insertion" genetics.
- Your Superpower: Your arms look naturally thick and full. Even when your arms are just hanging by your sides in a t-shirt, they will likely look big because the muscle fills out the sleeve completely.
- Your Challenge: It might be harder for you to develop a sharp, separated peak. Your bicep might look more like a log than a mountain.
Result C: The Average Bicep (1 Finger)
If you can fit about one finger (or maybe a finger and a half) in the gap, you have average or intermediate biceps.
- What this means: You have the best of both worlds. You have enough muscle length to have full-looking arms but enough of a gap to develop a decent peak. You are the "hybrid" athlete of the arm world.
Important Notes on the Test
- Check Both Arms: It is very common to be asymmetrical. You might have a 2-finger gap on your right arm and a 1-finger gap on your left. This is perfectly normal!
- Relaxed vs. Flexed: Make sure you are flexing. When your arm is relaxed, the muscle lengthens out. The gap is only truly measurable when the muscle is contracted and pulled up tight.
- Body Fat Matters: If you have a higher body fat percentage, it might be harder to see exactly where the muscle ends and the fat begins. Try to feel for the hard lump of the muscle underneath.
Deep Dive into Short Biceps
So, the finger test says you have short biceps. Welcome to the club! You are in good company. Many of the world's most famous bodybuilders, including the legendary Arnold Schwarzenegger, had short biceps with high peaks. Let’s break down exactly what this means for you, from the aesthetic pros and cons to the specific ways you should train.
The Aesthetic: "The Mountain Peak"
The defining characteristic of the short bicep is the peak. Because your muscle is bunched up in the middle of your upper arm, it has nowhere to go but up. When you flex, it creates a steep, dramatic curve.
- The "Wow" Factor: Short biceps are often considered the most "aesthetic" for posing. When you hit a front double bicep pose, those high peaks draw the eye and look incredible.
- The "Gap" Concern: The downside is that empty space near the elbow. Some people feel self-conscious that their lower arm looks "skinny" or unconnected to the bicep. When your arms are straight down at your sides, the high muscle belly can make the arm look less massive than it really is because the bottom half is mostly bone and tendon.
The Strength Factor: Is "Short" Weaker?
There is a common myth that short muscles are weaker because there is "less muscle." This is not true! Strength comes from how thick the muscle fibers are and how well your brain communicates with them, not just how long the muscle is.
- Explosive Power: In fact, having a longer tendon can actually be an advantage for explosive power. Tendons act like rubber bands. A long tendon can store more elastic energy. This is why many sprinters have "high calves" (short calf muscles with long Achilles tendons); it helps them bounce and run faster. While this applies more to legs, the principle holds: your arms can be incredibly snappy and powerful.
- Leverage: Biomechanically, you might have slightly different leverage than someone with long biceps, but in the gym, this difference is minor. You can still build massive, world-class strength with short biceps.
Training Strategy: Highlights and Fixes
Your training goal is twofold: maximize the peak (your strength) and fill the gap (your weakness).
Goal 1: Maximize the Peak (The Short Head)
Since you naturally have a peak, you want to make it as impressive as possible. This means targeting the long head (outer bicep) and the short head (inner bicep) effectively. While the long head creates the peak height, the short head provides the width that supports it.
- Focus: Exercises that involve supination (twisting your wrist). The more you twist your pinky up, the harder that peak contracts.
Goal 2: Fill the Gap (The Brachialis)
This is the secret weapon for short biceps. You cannot lengthen the bicep muscle, but you can build the muscle that sits underneath it.
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The Brachialis: This is a muscle that lies deep between your bicep and tricep. When you grow the brachialis, two things happen:
- It physically pushes your bicep upward, making your peak even higher.
- It adds thickness to the lower part of your upper arm (right where your gap is). A thick brachialis makes the arm look solid and "full" from the side view, effectively hiding the gap.
- The Brachioradialis: This is the large muscle on the top of your forearm. If you build this muscle up, it looks like it is "climbing" up your arm towards the bicep, visually closing the gap from the bottom.
Deep Dive into Long Biceps
If the finger test showed you have long biceps (zero fingers), congratulations! You possess the genetics for massive, sleeve-busting arms. You might not have the "tennis ball" peak, but you have the potential for arms that look like heavy construction equipment—thick, durable, and powerful.
The Aesthetic: "The Full Football"
The defining characteristic of the long bicep is fullness. Your muscle belly covers almost the entire span of the humerus bone.
- The "Sleeve Buster": Even when your arms are relaxed, they look big. T-shirts fit tighter around the arm because there is muscle everywhere, right down to the elbow.
- The "Flatness" Concern: The downside is that because the muscle is stretched out over such a long distance, it is hard to get it to bunch up into a high peak. Your flexed arm might look more like a curved log or an American football than a mountain. It can lack that "pop" or separation that makes muscles look detailed.
The Strength Factor: The Leverage King
There is some evidence to suggest that long muscle bellies (and the leverage points associated with them) can be beneficial for raw pulling strength.
- Better Leverage: With the muscle inserting lower on the arm, you may have a mechanical advantage in exercises like pull-ups, rows, and heavy curls. The lever arm is longer, allowing you to generate more torque.
- Injury Prevention: A fuller muscle belly can sometimes offer more stability around the elbow joint, potentially reducing strain during heavy lifting, although injury risk is mostly about form and load management.
Training Strategy: Carving the Stone
Your training goal is to create separation and build the peak. Since you already have the mass and fullness, you need to focus on shape and definition.
Goal 1: Build the Peak (The Long Head)
Just because you have long biceps doesn't mean you can't have a peak; you just have to work harder for it. The long head of the bicep (the outer part) is responsible for the vertical height. You need to hammer this head relentlessly.
- Focus: You need exercises that stretch the long head and force it to contract fully. This often involves keeping your elbows behind your torso or using narrow grips.
Goal 2: Create Definition (The "Cut")
Long biceps can look "blocky" if they aren't defined.
- Lean Out: To make long biceps look their best, having a lower body fat percentage helps immensely. It reveals the separation between the bicep and tricep, which prevents the arm from just looking like a tube of meat.
- Peak Contraction: You need to focus on the "squeeze" at the top of every rep. Since your muscle doesn't bunch up naturally, you have to mentally force it to contract as hard as possible to encourage that shape.
The Ultimate Training Guide (For Everyone)
Before we get into the specific exercises for your type, we need to cover the "Golden Rules" of arm training. These apply to everyone, whether you have long biceps, short biceps, or anything in between. If you break these rules, it doesn't matter what genetics you have; your arms won't grow.
Rule #1: Progressive Overload (The King of Growth)
This is a fancy term for a simple concept: You must do more over time.
If you curl 20-pound dumbbells for 10 reps today, and you are still doing 20 pounds for 10 reps next year, your arms will look exactly the same. You need to give your muscles a reason to grow.
- Add Weight: Try 25 pounds next week.
- Add Reps: Try to do 11 or 12 reps instead of 10.
- Improve Form: Do the same reps but slower and with better control.
- Decrease Rest: Rest for 45 seconds instead of 60.
Rule #2: Mind-Muscle Connection
It is easy to swing a weight up using your shoulders, your back, and your hips. This is called "ego lifting," and it builds nothing but injury risk.
- Feel it: You need to mentally focus on the bicep muscle squeezing. Close your eyes if you have to. Visualize the muscle fibers contracting.
- Squeeze: At the top of every curl, hold the weight for one second and squeeze your bicep as hard as you can. This is the difference between moving weight and training muscle.
Rule #3: The Eccentric (The Way Down)
Most people lift the weight up and then let it drop. Big mistake! The "eccentric" phase, the lowering of the weight, is where a huge amount of muscle damage and growth signaling happens.
- Control it: Lower the weight slowly. Count to three: "One... two... three..." until your arm is straight. Fight gravity. This will set your biceps on fire and stimulate massive growth.
Rule #4: Rest and Nutrition
Your muscles don't grow in the gym; they grow while you sleep.
- Protein: Eat enough protein (chicken, fish, eggs, beans, shakes) to build muscle tissue.
- Sleep: Aim for 7-9 hours of sleep.
- Frequency: Don't train arms every single day. They need 24-48 hours to recover. Training them 2-3 times a week is the sweet spot for most people[3].
The Best Exercises for SHORT Biceps
If you have short biceps, remember your mission: Build the brachialis to fill the gap, and target the short head for width.
Exercise 1: The Hammer Curl (The Gap Filler)
This is arguably the most important exercise for short biceps. Targets the brachialis and brachioradialis. Hypertrophy of the brachialis pushes the bicep upward, while a thick brachioradialis visually closes the elbow gap from the bottom[1].
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How to do it:
- Stand up straight with a dumbbell in each hand.
- Instead of palms facing forward, turn your palms inward to face your body (neutral grip). Think of holding a hammer.
- Keep your elbows tucked into your ribs. Do not let them float forward.
- Curl the weight up towards your shoulder, keeping your thumb side up.
- Squeeze at the top, then lower slowly.
- Why it works: This builds the thickness of the arm from the side view. A big brachialis pushes the bicep up, making your peak look even crazier, while filling out the lower arm area.
Exercise 2: The Preacher Curl
This exercise puts your arms in front of your body. This position creates "active insufficiency" for the long head, meaning the long head can't pull as hard. This forces the short head (inner bicep) to do more of the work.
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How to do it:
- Sit at a preacher bench (the one with the padded armrest).
- Adjust the seat so your armpits fit snugly over the top of the pad.
- Grab the EZ-bar (the zig-zag bar) with a wide grip.
- Lower the weight all the way down until your arms are straight (be careful not to hyperextend).
- Curl the weight up towards your chin.
- Why it works: It isolates the inner bicep, adding thickness and width to your arm, which complements the high peak you already have.
Exercise 3: Spider Curls
Similar to the preacher curl, this hangs your arms vertically in front of you, isolating the peak.
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How to do it:
- Set an incline bench to a 45-degree angle.
- Lay face down on the bench (stomach on the pad).
- Let your arms hang straight down towards the floor, holding dumbbells or a barbell.
- Curl the weight up without moving your elbows forward or backward.
- Why it works: It creates an intense contraction at the very top of the movement, maximizing that "mountain peak" shape.
The Best Exercises for LONG Biceps
If you have long biceps, your mission is to target the long head for a peak and focus on the squeeze for definition.
Exercise 1: Incline Dumbbell Curl (The Peak Builder)
This is the holy grail for long biceps. By putting the arms behind the torso, you stretch the long head across the shoulder. Research shows this position increases long-head activation, which is critical for building vertical height in long muscle bellies[2].
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How to do it:
- Set an incline bench to about 45 or 60 degrees.
- Sit back and let your arms hang straight down behind you. Gravity should be pulling your arms back.
- Keep your elbows pinned back. Do not let them swing forward.
- Curl the dumbbells up. Keep your palms facing up (supinated) the whole time.
- Why it works: It specifically targets the outer "long head," which is exactly the part of the muscle you need to grow to create a peak on a long bicep.
Exercise 2: Concentration Curls
This exercise removes all momentum and allows you to focus 100% on the squeeze.
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How to do it:
- Sit on the edge of a bench with your legs wide apart.
- Hold a dumbbell in one hand.
- Place the back of your upper arm against your inner thigh.
- Curl the weight up towards your opposite shoulder.
- Crucial Step: As you curl up, twist your pinky finger hard towards the ceiling.
- Why it works: The intense squeezing and twisting (supination) helps etch in deep separation and encourages the muscle to peak as much as physically possible.
Exercise 3: Drag Curls
This is an old-school bodybuilding secret for peak development.
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How to do it:
- Stand holding a barbell.
- Instead of curling the bar out in an arc, drag the bar straight up your body.
- Pull your elbows back behind you as you lift the bar. The bar should graze your t-shirt from your waist to your chest.
- Why it works: By pulling your elbows back, you take the front delts (shoulders) out of the movement and place pure mechanical tension on the long head of the bicep.
Bicep Myths Busted
There is a lot of "bro-science" floating around gyms. Let’s clear up the confusion so you don't waste your time.
Myth #1: "You can fill the gap."
- The Truth: As we mentioned, you cannot lengthen the muscle. No exercise will make the muscle fibers grow longer and cover the tendon. If you have a 2-finger gap, you will always have a gap. However, building the brachialis (the muscle underneath) makes the gap look less obvious by filling out the volume of the arm.
Myth #2: "Short biceps are bad genetics."
- The Truth: Absolutely false. Short biceps usually come with high peaks, which are prized in bodybuilding. It is simply a different aesthetic. "Bad genetics" would be muscles that refuse to grow no matter how hard you train, which is very rare. Most people just have poor training or nutrition habits.
Myth #3: "Long biceps are stronger."
- The Truth: While leverage might be slightly better for pulling, strength is mostly a result of training. A guy with short biceps who trains heavy for 5 years will be much stronger than a guy with long biceps who only trains for 1 year. Genetics plays a role, but hard work plays a bigger one.
Myth #4: "You need to do 10 different bicep exercises."
- The Truth: The bicep is a small muscle. You don't need a 2-hour arm workout. Pick 2-3 great exercises (like one for the long head, one for the short head, and one for the brachialis) and do them with intensity. More is not always better.
Photography and Posing Tricks
Let’s be honest, we all want our arms to look good in photos, whether it’s for Instagram or just a progress picture. Depending on your bicep type, you need to pose differently to show off your assets.
How to Pose Short Biceps
You have the peak, so flaunt it!
- The "90-Degree" Flex: Don't leave your arm hanging straight. Bend your elbow to at least 90 degrees. This bunches up the muscle and highlights your height.
- The "Press" Trick: This is a pro secret. When you flex, press your upper arm tightly against the side of your torso (your lats). This squishes the muscle, pushing it slightly outward and downward. It makes the arm look wider and can help visually reduce the gap slightly.
- Angles: Take photos from slightly above. This emphasizes the roundness of the peak.
How to Pose Long Biceps
You have the fullness, so show off the size.
- The "Extended" Flex: You don't need to bend your arm fully to look big. A "most muscular" pose (hands together in front of waist) works great for you because your biceps look thick even when not fully contracted.
- Supinate Hard: When doing a standard flex, twist your wrist as much as possible. Since you lack natural height, this twisting motion is the only way to force that peak to pop up.
- Angles: Side shots look amazing for you. Stand sideways to the camera and let your arm hang naturally or flex slightly. The thickness from shoulder to elbow will be very apparent.
FAQs
Q1: Can I actually change from short biceps to long biceps (or vice versa)?
A: No. You can’t move where the tendon attaches. But you can add size and shape by growing the biceps, brachialis, and forearms.
Q2: Which biceps type looks bigger in a T-shirt?
A: Long biceps often look fuller when relaxed. But either type can look huge with enough total arm muscle and lower body fat.
Q3: What should I do if curls hurt my elbow?
A: Reduce load, slow the eccentric, switch to cables/neutral grip, and cut weekly sets by 20–30% for 1–2 weeks. If pain persists, consult a professional.
Q4: How many biceps sets per week should I do?
A: Most people grow well on ~8–16 hard sets/week, counting direct biceps curls plus brachialis/forearm curls. Start lower if elbows get cranky.
Q5: Do I need to train biceps 3 days a week to grow?
A: Not necessarily. 2 days/week with good volume and progression is enough for most lifters. Add a third day if recovery is great.
Q6: What matters more: exercise choice or form?
A: Both matter, but strict form and progression beat fancy exercise hopping every time.
Conclusion: Embrace Your Genetics
At the end of the day, whether you have long biceps or short biceps, you have the potential to build impressive, strong, and head-turning arms.
If you have short biceps, stop obsessing over the gap. Embrace the fact that you have the genetics for a legendary mountain peak. Focus on hammer curls to build that thick base, and enjoy the fact that your flexed arms look like action figure arms.
If you have long biceps, stop worrying that you don't have a tennis ball on your arm. Embrace the fact that your arms look massive and full from every angle. Focus on incline curls to carve out that detail, and enjoy filling out your t-shirt sleeves effortlessly.
The "best" bicep is the one that is trained consistently, fed properly, and worn with confidence. Now that you know your type and you have the roadmap, the only thing left to do is get to the gym and start lifting. Your best arms are waiting for you!
Quick Summary Table
| Feature | Short Biceps (High Gap) | Long Biceps (No Gap) |
|---|---|---|
| Finger Test | 2 or more fingers fit in the gap. | 0 fingers fit in the gap. |
| Visual look | High, dramatic peak; thinner at elbow | Full, thick, "football" shape; no gap |
| Main Strength | Aesthetic "pop" when flexed | Looks big/thick even when relaxed |
| Main Weakness | Gap near elbow | Harder to get a sharp peak |
| Secret Weapon | The Brachialis (to fill the arm) | The Long Head (to create shape) |
| Best Exercises | Preacher curls, hammer curls | Incline Curls, Drag Curls |
| Best Pose | Arm against torso, 90-degree flex | Supinated flex, side relaxed shots |
Disclaimer: Before starting any new exercise routine, it is always a good idea to chat with a doctor or a fitness professional, especially if you have any past injuries. Lift safe!
References
- Coratella G, Tornatore G, Longo S, et al. Biceps Brachii and Brachioradialis Excitation in Biceps Curl Exercise: Different Handgrips, Different Synergy. Sports (Basel). 2023;11(3):64. Published 2023 Mar 9. doi:10.3390/sports11030064
- Oliveira LF, Matta TT, Alves DS, Garcia MA, Vieira TM. Effect of the shoulder position on the biceps brachii emg in different dumbbell curls. J Sports Sci Med. 2009;8(1):24-29. Published 2009 Mar 1.
- Nunes JP, Jacinto JL, Ribeiro AS, et al. Placing Greater Torque at Shorter or Longer Muscle Lengths? Effects of Cable vs. Barbell Preacher Curl Training on Muscular Strength and Hypertrophy in Young Adults. Int J Environ Res Public Health. 2020;17(16):5859. Published 2020 Aug 13. doi:10.3390/ijerph17165859
