Why Are My Arms So Skinny? (10 Common Mistakes To Avoid)

You’re working on your health and physique, but every glance in the mirror has you questioning – “WHY are my arms so skinny?”

I’m sure you did. Everyone has. But your skinny and weak arms don’t have to remain that way.

In this article, I will cover the 10 most common mistakes people make when trying to add more muscle to their tiny arms.

So, let's begin.

1. Not Exercising Your Arms Enough

Whether you like it or not, the main problem is you are not exercising your lanky arms (and probably your entire body) enough.

You need to understand that consistent effort and training to failure are necessary to improve muscle mass. You can't just do a few sets here and there and expect a massive muscle gain.

Sure, your arms work when you perform compound exercises like lat pull-downs, pull-ups, and bench presses, or when you do bodyweight and calisthenics training (like push-ups or bench dips).

Still, like any other muscle in your body, you have to target your biceps, triceps, and forearms with isolation exercises designed to work them.

How To Fix This?

No more than twice a week is needed because you’ll also work out your arms when you perform compound exercises, bench presses, rows, or pull-downs.

2. Not Enough Weight When Lifting

As we've just said, you need to use enough weight when lifting to build muscle size.

If you are not pushing yourself, you will not get larger muscles, regardless of the volume or frequency of your resistance training regimen.

Just doing 20 bicep curls or doing 30 bench dips won't help you achieve muscle hypertrophy. This won't even burn fat efficiently. As simple as that.

How To Fix This?

As mentioned above, make sure you train your skinny arms to failure.
From my experience, the best way to get rid of skinny arms is by lifting in the 8-12 rep range and using a weight you can do no more than 12 reps with, which is usually anywhere from 60 to 80% of your one-rep max. 

3. Not Allowing For Recovery Time

Funnily enough, just like not training your skinny arms enough, not allowing them to rest and recover is also a big mistake. Massive, in fact.

Building muscle heavily relies on the recovery period.[1] You break down your muscle tissue when you lift, and your body repairs it when you rest, which results in growth.

See Related - Should You Train Biceps & Triceps Together?

How To Fix This?

Ideally, you'll have your arms rest for 48 (maybe even 72 hours) between workouts. 
This is so you don't overtrain and give your body enough time to recover properly, which is why you should ideally train your skinny arms twice a week.
Also, proper hydration, sleep, and diet play an important role in recovery. 
Make sure you eat enough protein to promote muscle synthesis and get 8 hours of sleep per night, as well as drink 2 to 3 liters of water per day.

4. Focusing On The Wrong Exercises

Despite what many fitness influencers will tell you, you don't need to perform a billion curl variations, nor should you balance yourself on one leg, standing on a bench, while curling kettlebells suspended by resistance bands (despite what Joel Seedman says).

Training multiple muscle groups at once isn’t the most effective way to gain more muscle and get bigger arms.

Also, the equipment needed to effectively train your skinny arms is minimal.

How To Fix This?

Focus on the basics. Perform both compound and isolation shoulder, tricep, and biceps exercises that have always worked, and you should be golden.
Couple that with proper nutrition and progressive overload, and you have a sure-fire formula for massive guns. 

5. Not Using Progressive Overload Technique

Speaking of progressive overload, this is another mistake that many people make when trying to gain size in their arms.

It’s very common for gymgoers to stick with the same weight, reps, and sets for months and wonder why they’re not making any progress.

How To Fix This?

What you should do instead is increase the weights you are lifting in a very small and progressive manner each week.
For instance, if you started curling 15 lbs and did five sets of ten reps, next week, you should aim to increase the weight by a small margin or try to get 11 or 12 reps. 
If you manage to squeeze in 15 or more reps - use heavier weights. More weight equals bigger guns.
Just make sure you don't ego lift. A small increment of 5-10% is plenty.
That way, you will make sure that you are getting stronger and that your body has the time to adapt to the current weight, minimizing your chance of injury while making noticeable progress.
Man with Skinny Arms Doing Bicep Curls

6. Not Eating Enough Calories

It is virtually impossible to gain muscle mass if you're not in a caloric surplus. So, eat more food.

No matter how hard you train and how spot-on your technique is, if you're not getting more calories in (or the right type of food), you'll simply not gain any muscle - especially if you're lean, to begin with.

Some newbie gains might be present if you've never worked out before, but even then, you'll plateau rather quickly.

How To Fix This?

The only way to overcome this is by eating a bit more. Don't just go on a dirty bulk and hope to gain massive arms by overeating pizza and burgers. That’ll only result in excess body fat.
Aim for a moderate caloric surplus of around 10% to ensure proper gains. 
You could go up to 20% even, but if you find that you’re packing on more weight than you want to, start decreasing calories until you find the perfect balance. 

7. Not Consuming The Right Foods

As I just said, stuffing your face with fast food is not the way to go.

You should focus on eating a balanced diet that consists of lean proteins, complex carbohydrates, and healthy fats.

Aim to consume enough food depending on your height, weight, gender, and activity levels.

As for protein intake, a rule of thumb is to eat around 0.8 to 1 gram of protein per pound of body weight, but that's far from being the be-all and end-all.[2]

How To Fix This?

If you can't figure this out all by yourself, I strongly urge you to consult a nutritionist or a very knowledgeable fitness trainer. Proper guidance is key here.
Once you have a meal plan in place, it's just a matter of following it and using your food intake to fuel your workouts and build muscle. 

8. Not Training a Full Range Of Motion

I can't stress this enough, but you must go through a full range of motion in order to increase your arms size.

Too many people are performing half-reps, stopping halfway into the movement and missing out on essential gains.

Half-assing your final rep where you don't have any gas in your tank is somewhat fine because you're literally crushing your muscles at that point, but doing the same throughout the set because it's easier is FORBIDDEN.

How To Fix This?

Make sure your form is on point and every rep goes through an entire movement.
If you can't do it with the correct technique, reduce the weight and concentrate on good form first.
Your scrawny arms will thank you. 

9. Not Controlling the Eccentric Phase Well

Your muscles don't just contract and lift the weights.

The eccentric phase – where you are lowering the weight back down and stretching your muscles out – is just as important as the concentric phase.

Not controlling this part of the movement will not only hinder muscle mass growth but could lead to an injury.

How To Fix This?

Focus on controlling the eccentric phase and slowing it down a bit more, feeling the muscles work as the weight goes down instead of gravity doing all the work. 
If this causes you to drop to 8 reps instead of 10 - so be it. You're still achieving muscle hypertrophy through efficient strength training, so you’re good. 

10. Not Taking Supplements

Considering the food we're consuming today, it's pretty much impossible to get all the nutrients, vitamins, and minerals you need from food alone.

This is where supplements come in, as they can help bridge that gap so you can meet your daily needs.

See Also - Pros & Cons of Pre-Workout Supplements

How To Fix This?

Start by adding creatine monohydrate, whey protein, and some form of vitamin and mineral supplement to your daily regimen.
These should be more than enough to get you going and provide the base for a proper supplementation program.
On the same note, avoid overhyped "natural testosterone boosters" and similar stuff. They are worthless. 
Skinny Man Exercising with Dumbbells

How To Get Rid of Skinny Arms - Training Tips

Now that we've reviewed the mistakes, allow me to dish out a few training tips.

  • Train Arms 2-3 Times a Week

First, training your arms two to three times a week is a must.

That way, you can target all the different rep ranges and hit the desired training volume while simultaneously allowing your body to rest properly.

Any more than three times a week is too much for an average gymgoer.

  • Train to Failure in the 5-8 Rep Range
  • Train to Failure in the 8-12 Rep Range
  • Train to Failure in the 15-25 Rep Range

As for rep ranges, while 10-12 reps are optimal for muscle hypertrophy, incorporating all rep ranges in your routine is also beneficial for muscle growth.

Heavy weights in lower rep ranges and lighter weights in higher rep ranges will provide a balanced approach and supplement your usual training.

  • Train Every Rep Range Every Week (Different Workouts)

As an extension, you should strive to hit all three rep ranges every week. Split them into 80/10/10, maybe 60/20/20 (in favor of the 8-12 range).

  • Incorporate Drop Sets, Extended Sets, and Supersets

Also, drop sets, extended sets, and super-setting are your best friends here.

They'll help you push beyond failure and increase blood flow to the working muscles, thus creating a more conducive environment for growth.

With that being said, I still prefer a regular approach, but it's good to spice things up once in a while.

  • Focus on Isolation and Single Joint Movements

While compound movements do help build arms, they're not the most effective for arm development.

Isolation and single joint movements should take the biggest part in your arm routine, as they allow you to target a particular muscle and train it to failure without large muscle groups like the back or chest assuming the greater part of the load.

  • Use Machines and Cables to Train to Failure

Finally, machines and cables are great for arm isolation exercises as they provide steady resistance throughout the entire range of motion.

Thus, they're ideal for training to failure since they usually force you to implement a proper form, resulting in a much more isolated and efficient workout.

Skinny Woman Doing Dumbbell Bicep Curls

How to Get Big Arms? - Try This Awesome Workout Plan!

The best exercises for bigger arms are usually the simplest ones. But it can't hurt to be a little creative.

With that in mind, here's a simple yet effective workout plan to grow your arms.

4-Day Split Schedule

Splitting your workouts into four days will allow you to hit various rep ranges and train your entire upper body while building strength and arm size.

For the sake of focusing on the arms, I'll skip outlining the fourth day, which is leg day. However, just because I skipped it doesn't mean you should! All body parts need training.

Back + Biceps

Many back exercises also affect the biceps, so you can kill two birds with the right exercises.

However, just relying on compound back exercises to train your skinny biceps isn't enough. So, here's a simple routine you can do on your back and biceps day.

  • Deadlift (4-5 sets, 10-12 reps)
  • Pull-up (4-5 sets, 10-12 reps)
  • Lat pull-down (4-5 sets, 10-12 reps)
  • Chin-ups (4-5 sets, 10-12 reps)
  • Seated rows (4-5 sets, 10-12 reps)
  • Barbell biceps curls (4-5 sets, 10-12 reps)
  • Preacher curls (4-5 sets, 10-12 reps)
  • Cable curls (4-5 sets, to failure)

As you can see, this is a simple strength training program even the first-timer could efficiently do.

Chest + Shoulder + Triceps

Training the chest, shoulders, and triceps on the same day may seem like a lot, but if you're wondering how to get more meat on your arms - this might just be the way.

So, here's a simple routine you can do on your chest and triceps day:

  • Bench press (4-5 sets, 10-12 reps)
  • Incline dumbbell press (4-5 sets, 10-12 reps)
  • Overhead press (4-5 sets, 10-12 reps)
  • Lateral raises (4-5 sets, 10-12 reps)
  • Dumbell reverse fly (4-5 sets, 10-12 reps)
  • Skull crushers (4-5 sets, 10-12 reps)
  • Tricep extensions (4-5 sets, 10-12 reps)

As you can see, we start with the biggest muscle group and compound exercises all the way down to isolation ones.

Arms (Shoulders + Biceps + Triceps + Forearms)

Here's where you completely obliterate your arms.

  • Overhead press (4-5 sets, 8-10 reps)
  • Lateral raises (4-5 sets, 8-10 reps)
  • Dumbbell reverse fly (4-5 sets, 8-10 reps)
  • Dips (4-5 sets, 8-10 reps)
  • Tricep cable pushdown (4-5 sets, 8-10 reps)
  • Cable overhead extension (4-5 sets, 8-10 reps)
  • Dumbbell curls (4-5 sets, 8-10 reps)
  • Spider curls (4-5 sets, 8-10 reps)

I guarantee you - a spoon will feel heavy after this workout. Check out our other guides below to find the best arm workouts to help you pack on muscle.

Shirtless Man Flexing His Chest and Biceps

The Best Diet Plan for Bigger Arms

Now let's take at how to get enough food in your system to build bigger arms.

Recommended Calories

I can't quite tell you how many calories you need, as everybody needs a different amount due to their unique metabolic rate and activity level.

So, as I said earlier, visit a nutritionist or talk to your fitness trainer and dial in your calorie intake.

As a general rule of thumb, a 10% surplus is a good place to start.[3]


There isn't a one-size-fits-all answer regarding the best macronutrient split for bigger arms or muscle growth in general.

However, the best split, in my opinion, is 40/40/20 (protein/fats/carbs) respectively.

However, depending on your goals, body type, weight, and athletic activity, you may need to tweak this macronutrient split a little.

Sample Meal Plan

Finally, here's a sample meal plan to give you an idea of what your meals could look like.

  • Breakfast: Four eggs (two yolks) and a cup of oatmeal.
  • Snack: Protein shake or greek yogurt with blueberries.
  • Lunch: Chicken breast/ground turkey, a cup of rice/quinoa, and grilled zucchini.
  • Snack: Protein shake or an apple with almonds.
  • Dinner: Salmon fillet/steak, a cup of rice, and steamed vegetables.

As you can see, your food choices are anything but limited.

Common Questions About Skinny Arms

Are skinny arms genetic?

While genetics play a major role, and you can do nothing about muscle insertions, you can still build bigger arms with the right workout routine and diet plan.

How long does it take to get bigger arms?

While you should see the first results within the first two months, building massive arms will take years of hard work, dedication, and proper diet.

What body types are prone to skinny arms?

Body types are a bit of an overgeneralization, in my opinion. That said, the ectomorph body type is usually the skinny one that struggles to gain weight.

What exercises make your arms skinny?

Every exercise that properly engages your arm muscles will lead to muscle growth. The only difference is some will be more effective than others. So, don't worry. No exercise will make your arms skinny.


As you can see, building bigger arms is possible, even if you have skinny arms and bad genetics.

Sure, not everyone can be like Arnold, but everyone can still maximize muscle growth with the right workout and diet plan.

So, if your dream is to have bigger arms, avoid the mistakes outlined above and focus on proper diet, training plan, and progressive overload.


1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7909540/
2. https://examine.com/guides/protein-intake/
3. https://www.mdpi.com/2075-4663/7/7/154

Miloš Lepotic

Last Updated on January 17, 2023