how 20lb dumbbells are enough to build muscle

How 20lb Dumbbells Can Be Enough To Build Muscle As A Skinny Guy

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Are you looking to gain lean muscle with light dumbbells? Then this is the post for you. Because today, I’ll be explaining how 20lb dumbbells are enough to build muscle.

As a general rule, 20-pound dumbbells are suitable for the average beginner to gain up to 5 pounds of lean muscle. This requires the 20-pound dumbbells to be used for 15 reps per set for isolation exercises targeting all the major muscle groups.

When I first started working out, I only had a pair of 20lb dumbbells. I just didn’t know how to use them!

Fast forward 2 years of regular training and 40 pounds of muscle gains, I’m now experienced enough to create the ideal 20lb dumbbell workout to build muscle.

And that’s what I’ll be sharing with you today!

Let’s go!

Are 20lb Dumbbells Enough To Build Muscle?

20lb dumbbells are enough for skinny guys to build muscle (and even more so for beginners).

Although they won’t be as effective as say a pair of 70 pounders, 20 pounds is better than no pounds!

And if you apply the right form, technique, and exercises, you can expect to make some noticeable muscle gains.

But don’t just take my word for it.

I tracked down a Quora and Reddit poll to find the public opinion on 20 lb dumbbells:

And here are the aggregated results:

pie chart showing 20lb dumbbells are enough to build muscle

86% of users agree that a pair of 20lb dumbbells are enough to build muscle. But you should also be aware of the caveats.

Firstly, 45% of those who agreed that 20 pounders are sufficient, also noted the limitations of using these relatively light dumbbells.

Secondly, a further 27% who agree that 20 pounders are enough for muscle development, also emphasized the importance of performing the right exercises.

Next, I’ll explain the caveats for using 20lb dumbbells.

Pro’s And Con’s Of Using 20 Pound Dumbbells

Here are some of the advantages and disadvantages of using 20lb dumbbells:

1) Cheap and convenient.1) Limited progression potential.
2) Good for low strength levels.2) Longer workout durations.
3) Beginner-friendly.3) Unsuitable for big lifts.
Advantages and disadvantages of using 20lb dumbbells.


  1. Cheap and convenient- 20lb dumbbells are the cheapest on the market, costing around $150 for a pair of adjustable’s. I’d recommend you to buy adjustable over fixed-weights as these are cheaper overall and you get the desired weight increments.
  2. Good for low strength levels- light dumbbells are effective for beginners to build foundational strength before progressing to heavier weights.
  3. Beginner-friendly- 20lb dumbbells are considered light, and a perfect way to start your weight lifting journey by learning the correct form and technique.


  1. Limited progression potential- newbies will quickly outgrow 20lb dumbbells. After you’ve reached a certain strength level, you’ll need to increase the weight or find other ways to increase intensity (See below).
  2. Longer workout durations- light weights can be as effective as heavy weights if rep count is increased. But increasing reps also increases workout duration. Reps refer to the number of exercise repetitions in a set.
  3. Unsuitable for big compound lifts- 20lb dumbbells are not heavy enough for effective compound lifts such as pressing, rowing, squatting, and deadlifting. These are the most effective muscle builders.

All in all, 20lb dumbbells can be enough to build muscle as a beginner.

These dumbbells are cheap and convenient, and they are perfect for newbies to start lifting weights.

20lb dumbbells need to be replaced after you have outgrown them

However, you’ll also find that strength gains are made quickly as a beginner.

These are called newbie gains, and it won’t be long until you need to increase exercise volume and intensity to continue making muscle gains.

As such you should consider your mid and long-term training goals before choosing to buy a pair of 20lb dumbbells.

Check out my other article to determine which dumbbell weight to buy!

What Can You Do With 20lb Dumbbells?

Dumbbells are an extremely versatile free weight (even at light weights).

Heavy dumbbells can be used to perform all the main compound lifts to build muscle. These include exercises such as the bench press, shoulder press, bent-over row, and squat, and deadlift.

However, light dumbbells won’t cut it for these exercises since they recruit multiple muscles and therefore require heavier weights.

The exception would be if you are extremely weak. But even if that’s the case, you’ll still find yourself quickly outgrowing 20lb dumbbells due to the newbie gains period.

20lb dumbbells are instead mostly suitable for isolation exercises such as:

  • Bicep curls- engage the biceps muscles are upper arm mass.
  • Tricep extensions/kickbacks- work the triceps for a well-defined upper arms.
  • Lateral raises- target the side shoulders.
  • Front Raise- front shoulder- target the front shoulders.
  • Chest fly- isolate the pectoralis major and minor in the chest.
  • Dumbbell crossover- target the upper chest muscles.
  • Reverse fly- work the mid and upper back muscles.
  • Ab crunch- train the rectus abdominis “6 pack” muscles.
  • Leg Raise- emphasise the lower ab region.

20lb dumbbells can also be used to add resistance to muscle-building bodyweight exercises such as:

  • Pull ups- build a wide and thick back.
  • Chin ups- work your back as well as the biceps.
  • Pistol box squats- are a beginner-friendly way to double the weight of your dumbbell.
  • Lunges- are a great way to work the legs one at a time (essentially doubling the dumbbell weight).
  • Squat presses- are a high intensity leg and shoulder exercise.

The good news is that all these exercises can be sufficient for skinny beginners to build strength and promote hypertrophy (muscle growth) in the early days of training.

But you’ll eventually have to find creative ways to keep your muscles challenged for growth.

Check out my other article for another dumbbell workout to get shredded (with heavy dumbbells).

Remember: 20lb Dumbbells Are Light!

An important note to remember is that 20lb dumbbells are considered light for a male wanting to build muscle.

You won’t be able to effectively stimulate your muscles for growth in the 5 big compound lifts (bench press, shoulder press, row, squat, and deadlift).

These exercises involve too many muscle groups, and as such, the light weight of your 20lb dumbbells is further diluted.

However, 20lb dumbbells are suitable for beginners with a low starting strength to perform the smaller isolation lifts mentioned previously. And these are enough to build a leaner, more athletic-looking body.

example of a lean and athletic body

A good weight to start building muscle is one which fatigues your muscles in 15 repetitions for the specific exercise.

You would then have to use creative methods to increase exercise intensity (since you will likely outgrow 20lb dumbbells very quickly).

Next, I’ll give you a 20lb dumbbell workout and way to increase exercise intensity.

Check out my other article to determine your ideal lifting weight-load to build muscle!

The Kalibre 20lb Dumbbell Workout Routine.

Here’s an example of a 20lb dumbbell workout program (assumes you have a pair of 20lb adjustable dumbbells).

The program comprises two distinct workouts:

Workout A

Chest-push up or chest fly.

Shoulders- lateral raise.

Arms- bicep curl.

Abs- ab crunch.

Back- reverse fly.

Legs- pistol box squat.

Workout B

Chest- dumbbell crossover.

Shoulders- front raise.

Arms- tricep extension.

Abs- leg raise.

Back- pull up (preferred)) or one-arm row (alternative).

Legs- dumbbell forward lunge.

You’ll perform 3 training days per week, for a month. This will allow your body to adapt to your new training.

Each week, you’ll complete workout A, rest a day, workout B, rest another day, and then finish with workout A again.

It doesn’t matter which day you work out. The important point is to complete 3 workouts per week, each separated by a rest day.

With workout B, the back workout should ideally be pull-ups. But if you don’t have a pull-up bar, you can substitute this with one-arm rows.

Regarding dumbbell weight- choose a weight that challenges you for 15 reps per set. This will be the rep range for most of your exercises when using 20lb dumbbells.

The exception would be for push-ups and pull-ups, which you should start with your bodyweight and progress to harder variations such as slow push-ups or dumbbell-weighted pull-ups.

After 1 month performing this programme, you should increase to 4 training days.

Don’t forget, you should also be eating a caloric surplus with enough protein for your body weight!

Details of muscle building nutrition can be found in my other article, tips to build muscle as a skinny guy.

How Many Reps Of 20lbs Should You Do?

The recommended rep-range for hypertrophy (muscle growth) is 8 to 12 reps using a heavy weight.

However, you are severely restricted by 20lb dumbbells.

To counter this problem, you’ll perform 15 reps for each dumbbell exercise. You’re effectively making up for the limited weight by performing more reps.

But never exceed 15 reps per set. If you find 15 reps becomes easy, you should increase intensity rather than increase reps (see below).

With the push ups and pull ups, aim for 8-12 reps per set.

And if you can’t currently do either, you should slowly work towards mastering them. Push ups and pull ups are essential bodyweight exercises to build arm, chest and back muscle when you only have 20lb dumbbells!

Finally, aim for 4 sets per exercise.

Find out how to do a pull up in my other article!

Increasing Intensity For 20lb Dumbbell Exercises.

You’ll find that after a few months, those 20lb dumbbells will likely begin to feel real light.

That’s because you have gained muscle size and strength. Good job on that!

But your next hurdle is to find ways to apply progressive overload (increasing workload to keep challenging your muscles)

The most popular way to apply progressive overload is to increase dumbbell weight.

But since you’re stuck with measly 20 pounders, you’ll have to use other methods instead.

The first method would be to increase the number of training days (as mentioned previously).

time under tension training

The second method involves increasing decreasing rep tempo.

Rep tempo simply means how long it takes to complete a rep. And it can be decreased by prolonging the concentric (upward) and eccentric (downward) phases to around 2 to 3 seconds each.

Once you have mastered this, you can further decrease the tempo to 3 to 4 seconds per phase (6 to 8 seconds per rep).

This is known as time under tension (TUT) training. And TUT is extremely effective at stimulating protein synthesis and muscle growth.

Check my other article to determine your ideal number of training days!

When to Upgrade Dumbbell Weight.

20lb dumbbells will only last you for so long and get you so much muscle gains.

But if you’re serious about building a powerful physique, you’ll have to eventually upgrade your dumbbells.

The sign to upgrade your dumbbells is when 15 reps with applied TUT becomes easy. If this is the case for most of your exercises, then you’ll want to shop for new dumbbells!

And I’m guessing you don’t want to replace your new dumbbells anytime soon right? So what dumbbell weight should you get?

Here’s an estimation for a 140 pound skinny beginner:

Dumbbell Weight (Per Dumbbell)Estimated LifespanEstimated Muscle Gains
20lb3-6 monthsUp to 5 pounds
50lb6 months to 3 yearsUp to 20 pounds
70lb3-5 yearsUp to 30 pounds
90lb5+ years30+ pounds.
Estimated lifespan and muscle gains from different dumbbell weights.

Ideally, you would have planned ahead and chosen the correct dumbbell size.

But don’t worry if you have already got your 20lb dumbbells. Use them till they’re no good, sell them, and reinvest in a new pair which will last you a much longer time!

Take a look at my other article to find out why dumbbells are worth the money!


Today I’ve explained how 20lb dumbbells can be enough for skinny guys to build muscle. I’ve also included a 20lb workout prgramme for skinny guys to start building muscle immediately.

Light dumbbells are adequate for the average male beginner to build muscle (especially if you’re currently skinny and/or have a low starting strength).

However, after around 6 months training (sometimes sooner), you’ll likely find the need to upgrade your dumbbell weight.

Therefore you should ideally choose 50+ pound dumbbells if you haven’t bought them already.

Will you be trying the Kalibre 20lb dumbbell workout?

Let me know in the comments below! Alternatively, download the FREE Kalibre Muscle Blueprint to find out how I gained 40 pounds of muscle!

bananas helped me transform my body

Thanks for reading guys!

Peace Out,


(Biochemistry BSc, Biomedical Sciences MSc, Ex-Skinny Guy)

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