A muscular man loads a barbell with weight for a bulking workout.
TRAIN
Centr Team

Everything you need to know about building muscle mass

Centr Team

Have you heard about Chris Hemsworth’s mission to build his biggest body ever for Thor: Love and Thunder? Maybe you want to gain weight to perform better in a sport, cut body fat and add lean muscle to improve your overall health and fitness, or achieve a specific body target.

In other words, you want to know how to gain weight and build muscle – fast. While we’d love to tell you there was a quick and easy way to get to your goal size, the reality is that gaining significant mass takes determination, focus and patience.

The good news is, whatever your goal, we have the tips you need to gain weight naturally and safely. Read on to discover everything you need to know about adding muscle mass, with tips including estimating your calorie intake for muscle gain and how quickly you can expect to see results.

Calculating your ideal calorie intake for muscle gains

We know you’re in a rush to get lifting, but your performance in the kitchen is just as important as your reps in the gym. Whether you want to build lean muscle or add maximum mass, good nutrition is essential.

Chris Hemsworth’s stuntman Bobby Holland Hanton drinks a muscle-building smoothie on set.
1
/2

During his transformation for the film Thor: Love and Thunder, stuntman Bobby Holland Hanton consumed 4000 calories per day, spacing his nutrition over 8–10 small meals.

It all comes down to:

  • Adequate calories to fuel your training and growth.

  • Adequate protein to optimize muscle protein synthesis.

  • Timing your nutrition to perform at your best and maximize growth.

To gain weight and muscle, your body needs to be in a calorie surplus – that means you’re taking in more calories than you burn up as energy. But how many calories does it take to build muscle? There is no magic number. Every individual is different, and your needs will depend on a range of factors, from genetics to body size and training history.

For Centr Power, we produced a calculator based on the widely-used Harris-Benedict equation. This is the bulking equation Chris and his personal trainer Luke Zocchi have used over the years when preparing for movie roles. You can access this calculator along with the complete training and nutrition program when you start your free trial with Centr. This Harris-Benedict scientific formula measures:

  • Your basal metabolic rate (BMR) – how many calories your body burns to function.

  • Your activity levels – for instance, you may lead a largely sedentary lifestyle, or have a physical job. You might train heavy 6 days a week, or get light exercise every second day.

These two measures are then combined to find your total daily energy expenditure (TDEE). Once you have your TDEE, you then factor in your body type and goal to estimate your additional calorie requirements to build muscle.

We know these equations and numbers can be overwhelming, so Centr Power provides a nutrition guide, TDEE calculator and an in-app weights tracker to help you achieve success in your muscle-building journey.

A protein-packed Green Super Smoothie from the Centr Build Muscle meal plan.
2
/2

Protein-packed drinks like our Green Super Smoothie are an easy way to add nutritious calories to your diet.

To back up your training, it’s important that you know what foods you should eat when you want to gain weight the healthy way. Luckily, we’ve got the answers to all of your muscle-building nutrition questions, plus some recipes to get started.

What is a bulking workout?

Now we’ve covered how to estimate the calories you need to build muscle, it’s time to switch focus to training. What kind of exercise will support you on your journey to gain weight and muscle?

You probably already know that strength training in the form of lifting weights is the most efficient way to build muscle mass through exercise. While it is possible to build muscle using only bodyweight exercises (or calisthenics), adding weights to the mix will make gaining mass much easier.


Progressive overload is upping the intensity of your training so that your body is forced to adapt and get stronger.


Adding muscle mass requires damage and repair. During exercise, your muscles endure microscopic damage. When you rest, your body starts to repair the tissue by fusing the damaged muscle fibers together. This leads to stronger, thicker, and greater numbers of muscle fibers – also known as muscle growth. This is how you get bigger – and stronger – as a result of exercise.

But here’s the catch. Your body adapts to exercise quickly, so to continue gaining mass you need a muscle-building program that uses progressive overload. What’s that? Progressive overload is upping the intensity of your training so that your body is forced to adapt and get stronger. This is the approach Centr Power uses, turning up your training intensity week by week by increasing the weight you lift, increasing reps and sets, and continually challenging your muscles to spur growth.

The kinds of exercises you use are important too. If you want to build muscle, your training program should prioritize compound or multi-joint movements.

“Any muscle-building program worth your time is going to focus on those big compound moves,” says professional bodybuilder and Centr expert Torre Washington. “Because compound exercises are multiple joint movements, they allow you to work different muscle groups all at once.”

Bodybuilder Torre Washington performs a front squat with a loaded barbell to build muscle.
1
/2

Torre Washington demonstrates a classic compound movement for building muscle – the barbell front squat.

A good example of a compound exercise is a squat, which moves both your hip and knee joints while engaging your core, glutes, quads, hamstrings and calf muscles. While you could spend hours working each of those muscles individually, compound movements make workouts shorter and seriously efficient for your full-body muscle growth. Plus, if you’re strong all over, you’ll be able to lift heavier and add serious size when you do hit individual target areas.

Just how active you need to stay outside of lifting weights will depend on your goal. Is your goal to build lean muscle and definition, without getting too bulky or adding body fat? Centr member Erik Conover achieved this with Centr Power, the muscle-building program inspired by Chris’s Thor training routine. After completing the 10-week program, Erik went from 202 lbs (92kg) up to 210 lbs (95kg), while lowering his body fat percentage from 16.8% to 11.2% body fat.

When the goal is to add serious bulk – getting as big and strong as possible – an increase in body fat won’t be such an issue in your journey. Because of this, you might find that you don’t need to incorporate a lot of extra activity outside of your primary weight lifting days.

While progressive overload is good, overtraining is not. Rest and recovery is a crucial element of your weight gain plan. Your training schedule should allow space for rest days and deload weeks. Deloading is used in weight training to give muscles a chance to rest and recover, usually before moving onto a new program or phase of training. You may take it easier in the gym by reducing your training volume, lifting lighter weights, or doing workouts with no weights (e.g. bodyweight functional training). Even if your body feels like it could keep going, it’s a good idea to give it a deload week before moving into another period of heavy training.

And don’t forget, because muscle protein synthesis happens when you sleep, getting good quality zzzs is another essential part of your schedule.

Impressive before and after photos that show Eric Conover’sphysical transformation.
2
/2

Over 10 weeks training with Centr Power, Erik gained 3kg while lowering his body fat percentage from 16.8% to 11.2%.

How fast can you gain muscle?

If you’re doing all the right things with your training, diet, recovery and sleep, the average man can gain 1–2lbs (0.5–1kg) of lean muscle mass per month, and the average woman up to 1lb (0.5 kg) per month.

If you’re a beginner, you are likely to achieve significant strength and muscle gains in the first few weeks of lifting weights. These ‘newbie gains’ are caused by rapid improvements as your body adapts to a new style of training. If you’re already doing regular strength training? It will take longer to notice results, but consistently progressing your training will lead to growth.

Individual bodies advance at different rates, so don’t give up if you’re not seeing visible results or progressing at a slower pace than others. Stay consistent and the results will come.

Ready to build muscle mass and achieve your goals? Designed by Chris Hemsworth and Luke Zocchi, Centr Power is the muscle-building program that caters for everyone. With Beginner, Intermediate and Advanced training levels, tutorials to help you nail your form, and expert nutrition advice, we’ll get you on track to building serious muscle, strength and size.

start-free-trial
Start your Centr journey with a 7-day free trial

Get Chris Hemsworth's team of the world's best trainers, chefs and well-being experts in your corner.