How to Gain Muscle Mass
Written by Fritz Nugent

In my humble opinion as one of the Invictus Nutrition Program coaches, gaining body weight in the form of muscle mass is the most challenging task. Of course there is a small percentage of people who can gain muscle mass or lose body fat quickly, but they are the exception and definitely not the rule. Most people have to work with steady consistency and over many weeks and months to realize lean mass gains. 

Let’s define this. When people gain body weight, they can gain this from lean mass gain (water, muscle, bone, other non-fatty tissues) or fat mass. Perhaps a sumo wrestler, rugby prop, or American football offensive tackle may want to gain body mass in any form because success in their sport or position depends partly on having a large body mass. For most people, a lean mass gain is desirable, which means that most of the body weight gained is from muscle, bone, water, and other non-fatty tissues.

Before we talk about how to eat to gain weight (lean mass), let me outline how important the other lifestyle factors are to mass gain: very.


Spend at least 8 hours in bed each night. When you are in bed, you aren’t burning extra calories. You are also giving your body ample recovery ability to construct lean tissue. Sleeping less will increase your stress, decrease your recovery, and you will expend more energy each day, making your minimum caloric target for mass gain higher, placing greater strain on your immune and digestive systems. 


If you have the power to do so, limit ALL stressors to be in alignment with your mass gain. This means that the lower you can keep work and life stress, the harder you can train in the gym and still come back recovered the next day. This will help you gain faster. Self-care processes like journaling, reading, walking, hiking, beach time, prayer, etc. become massively powerful anti-stressors to help you gain muscle.


When you’re in the gym, get after it. You’re not going to passively gain muscle. You have to bust your ass. When lifting for strength, stay on-tempo and GRIND. Three to four quality training sessions a week is enough. The more you train, the more food you will have to eat! There’s a delicate balance that must be found here, and this is unique to each person. You hear us coaches say this one often – more is not better. Better is better. Training two days of double sessions and two more days of single sessions may not be optimal. Be in search of what gets you feeling good in the morning. If you wake up unrested after 8 hours in bed, chances are that you are overshooting your body’s ability to recover from your training load. Back off a bit and watch your gains skyrocket.


I have observed that when people have an intention to gain body weight, they will almost always gain some fat along with new muscle mass. The amount of fat that one gains, in my opinion, is directly proportional to how far over their energy expenditure they consume each day. If you look in a nutritional textbook, the standard guideline is to gain 1 pound of body weight a week, you must eat a surplus of 500 calories a day.


500 surplus calories x 7 days = 3500 surplus calories/week, which equals about 600 grams of extra carbs/protein/fat consumed. One pound is 454 grams, so this value is suggested for those wanting to gain a pound each week

The nutritional texts also suggest the upper limit on “safe” mass gain is an extra 1000 calories a day, which doubles our equation above, providing an extra 2-3 pounds of energy consumed above what is “burned” or utilized by our body. This is suggested to provide 2 pounds of mass gain a week.

I disagree with both of these suggestions and will explain further below…

Back to Caloric Surplus

Now here’s the kicker – almost everyone I coach who wants to gain weight wants it NOW and is willing to start at that 1000 calorie surplus. If a client is really gung-ho about gaining and wants to try this, I’ll humor them. Eating an extra 1000 calories of high quality food (if you eat shit quality food you’ll surely gain weight and I guarantee it won’t be mostly muscle…) is tough. It’s a job in itself – all the meal planning, shopping, cooking, cleaning, storage, reheating…it’s a lot. And your poor digestive system – let’s call him Charles – is used to eating 2000 calories a day and now you want to give him 3000 calories? Poor Charles. That’s like your boss coming up to you and asking you to work 12-hour shifts 5 days a week instead of 8’s. Imagine how you’d feel – Charles is also pissed and sad. So no wonder my clients who “try” to eat 1000 extra calories a day fall off quickly and say “it’s not working”. It is difficult to be consistent when you’re asking too much of your body. This is similar to wanting to improve your back squat from 200 lbs to 300 lbs. If your max is 200, you don’t put 250 on the bar and shoot for sets of 10. Instead, you build slowly over time. In my opinion, mass gaining is no different.

If you are currently eating 2000 calories consistently, I almost always start people off with a 10% calorie bump. That moves the person up to 2200 calories. This is manageable and allows for consistently eating over daily expenditure. A small calorie surplus also increases the likelihood that the weight gain will be mostly muscle! So we bump the calories up 10% and wait. Weigh-in once or twice a week. Not gaining after two weeks? Bump up another 10%. Now we’re near 2400 calories. This 20% bump almost always initiates weight gain, and the previous two weeks at a manageable 10% jump doesn’t freak Charles out too badly. It’s consistent. Then we keep working patiently, changing calories and macros based on what the body feedback tells us.


For macros, you’ll need to keep protein constant – at about 1 gram per pound of lean body weight. Fats can stay at about 25% of total calories (for larger individuals, this can increase to help offset massive amounts of carbohydrate intake which can blunt the insulin response after months of gaining, causing excessive fat accumulation and push one towards metabolic syndrome), and the rest of your energy needs from carbohydrates.

For How Long

Most people can realize a predominately lean mass gain for about 2-4 months. There is a point where the weight gain begins to be more fat than muscle, and at that point, the calorie surplus can be decreased to work towards maintenance. After a period of weight gain, one must then spend time holding onto that extra body mass to allow for connective tissues and bone to adapt because they do so at a slower rate than muscle. Also, this gives your body time to change it’s set weight point, making long-term maintenance of your new heavier body weight more realistic. This is a perfect time to work on “recomping”. We talked about this before, in March. The idea is to stay at one weight while working to improve leanness. This is a factor of decreasing body fat while gaining muscle mass.  After a 3-6 month period holding your body weight constant, then you can decide to push for another gain.

More Math (skip if you don’t like math)

Let’s say you are 15% body fat and weigh 100 lbs (for easy math). So you’re 85 lbs of lean stuff, and 15 lbs of fat. If you gain 5 lbs of pure muscle, that makes you 90 lbs lean and 15 lbs fat, changing your body fat to 14.2%. This is obviously ideal! Now let’s look at how things usually play out. Within that 5 lb gain, you add 3 lbs of muscle and 2 lbs of fat, this puts you at 88 lbs of lean stuff and 17 lbs of fat, bringing your body fat percentage to 16.2%. You gained 3 lbs of lean mass – congrats! And you are also a little fatter for it. And I want you to realize that this is OK. If you want to gain muscle mass, you will have to tolerate some fat mass accumulation. 

All of this takes great patience, consistency, and determination. Imagine the amount of good habits you’ll need to be successful. Your sleep, stress, and movement (training) must all be on-point before even attempting to change your nutrition. Nutritionally, you will need to learn how much food you need to stay at your current weight, and then steadily add until you induce weight gain. There must be consistency in your food tracking, or it will be difficult to induce a slight increase. If you are inconsistent, then you will be forced to eat more food, which increases digestive strain. Meal planning, prepping, and cooking skills are a must. This helps to minimize the time and energy spent on those tasks. Inefficiencies here often cause frustration at the sheer amount of time spent each week on these tasks. And having sound cooking skills is HUGE because then you can rely on your own meals instead of having to spend extra money purchasing someone else’s food. Once you become a good cook, your own food will always trump food from another source. And you’ll be able to keep eating similarly without tiring of your meals because you have the skills to keep your dishes tasty and interesting. All in a perfect world…

So there you have it. Questions? Send them my way! 

Also Check Out…

Meal Prep Strategies

Think Like a Chef: How Adopting ‘Mise en Place’ Makes Meal Prep Easier 

Basic Kitchen Skills w/ Confit TJ

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