Muscle Growth And/or Weight Loss: How Long Does It Take? (Exact Number of Weeks)

When will your muscles grow? And weight loss: how long does it take? If you're sick of the advice "Be patient", this article was written for you.

Fit and toned sportswoman working out in functional training gym at the beach

🙋 Raise your hand if the following sound familiar:

  • “Building muscle takes time! Keep your head down, and you'll 100% see results."
  • “Losing weight doesn’t happen overnight. Be patient! It’ll happen for you soon-ish.”

I know. Those can grate on the nerves.

Obviously, you know you won't wake up one day with boulder shoulders, sleeves-ripping arms, and powerful, wow-worthy legs. Neither will you magically drop all that excess weight in a flash. You are patient.

All you want to know is how long it’ll take for you to see results. Like, actual numbers (so you can stay motivated, count down, or plan a beach vacay).

Is that too much to ask?

Good news: it’s not. Below, we reveal how you can calculate the exact number of weeks you need to bag your dream physique 🥅

How long does it take for muscles to grow?

A 2017 study published in the European Journal of Applied Physiology provides answers.

After having 13 untrained men perform unilateral concentric-only dumbbell curls and shoulder presses twice weekly, the researchers found evidence of muscle growth at the 4-week mark.

That said, the muscle growth wasn’t anything to shout about. The researchers noted that it wasn’t noticeable to the naked eye — but observed only thanks to ultrasound.

So, how long to build muscle? The answer appears to be 4 weeks.

When can I (or someone else) see the results? 👀

But, as we all know, that’s not really what you want to know … right? What you’re more interested in is how long it takes before people (*ahem* maybe a special someone *ahem*) notice all that hard work you’ve put in.

For that, we’ll need to look at 2 additional pieces of research:

1️⃣ A 2020 study published in the Journal of Clinical and Translational Research, and

2️⃣ A 2007 comprehensive review of over 200 studies published in Sports Medicine

These suggest that, on average, we can increase our muscle size by about 1% to 6% per month.

So, let’s assume that your current back width — measured horizontally across the shoulder blades, from each armpit — is 15 in (38.1 cm).

In line with the findings, a realistic rate of muscle growth for you would perhaps be 3% per month (disclaimer: this can vary according to a handful of factors, which we’ll discuss in a bit), which means your back would measure:

  • 15.45 in (39.2 cm) after a month of training
  • 15.91 in (40.4 cm) after 2 months of training
  • 16.39 in (41.6 cm) after 3 months of training

Now, objectively speaking, it’s unlikely anyone would notice a 0.45 in (1.1 cm) increase in your back width. But they just might start picking up on a difference at the 2- or 3-month mark.

Bottom line? Generally, it'll take 2 to 3 months before your gains are observable and longer for them to enter the "très” noticeable territory.

1%, 3%, or 6% — these factors can affect your muscle growth rate

Whether you grow muscle slowly or quickly could depend on the following:

  • How smart/hard you’re training. Are you hitting your muscles with enough volume? Intensity? And what about your exercise choice?
  • Your training experience. More experienced lifters will generally experience slower muscle growth rates than "newbies".
  • Your nutrition. Are you eating enough protein? What about your other macronutrients — have you tweaked their ratios to best fuel your workouts without exceeding your calorie budget?
  • Lifestyle habits. Think stress management, sleep, and recovery.
  • Your body fat percentage. Technically speaking, this won’t affect your rate of muscle growth, but it will affect how quickly you’ll be able to see your gains. (The fat “hides” your muscles!)

What should your body fat percentage be? Find out below:

What’s a Healthy Body Fat Percentage? Can You Get Too Lean?
Think of a really fit person. How do they look? Go-to answer: very good — but is it healthy? What’s the risk of getting so lean? Find out here.

Weight loss: how long does it take?

Alright. We’ve got muscle growth down.

Time to talk about weight loss — how long does it take? Here's what you need to know. Doctors and health experts recommend a weight loss of 1 to 3 pounds (0.45 to 1.36 kg), or about 1% of your body weight, weekly.

So, if you stick to those recommendations, you'll likely start seeing differences at the 2- or 3-month mark (just like muscle growth).

Note: while you may not necessarily be able to observe anything outwardly different about yourself earlier than that, you’ll often realize that your clothes are fitting better. Or that you “feel lighter” even though the numbers on the scale may not have moved much.

A teeny, tiny complication

Let’s say you want to lose 20 pounds (9 kg).

Given the typical weight loss rate, you can expect to hit your target weight within ~7 to 20 months, right?

It's a little hard to say.

That’s because if you’re lifting weights — this is highly encouraged, by the way — you'll inevitably gain some muscle while trying to lose weight. And that can affect your weight. So, while your body weight may not decrease, your body composition is improving.

You’re losing fat while gaining muscle … which is why, perhaps instead of (or in addition to) tracking your body weight, you should also track your body fat percentage.

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Weight loss: how long does it take? What about muscle growth?

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Gentil, P., Budzynski-Seymour, E., Souza, D., Steele, J., Fisher, J. P., & Bottaro, M. (2020). Evaluating the results of resistance training using ultrasound or flexed arm circumference: A case for keeping it simple? Journal of Clinical and Translational Research, 7(6), 61–65.

Stock, M. S., Mota, J. A., DeFranco, R. N., Grue, K. A., Jacobo, A. U., Chung, E., Moon, J. R., DeFreitas, J. M., & Beck, T. W. (2017). The time course of short-term hypertrophy in the absence of eccentric muscle damage. European Journal of Applied Physiology, 117(5), 989–1004.

Wernbom, M., Augustsson, J., & Thomee, R. (2007). The Influence of Frequency, Intensity, Volume and Mode of Strength Training on Whole Muscle Cross-Sectional Area in Humans. Sports Medicine (Auckland, N.Z.), 37, 225–264.