Muscle Gain Math

So there is a fairly short list of topics that I keep meaning to write about and never seem to get around to (I’m running out of stuff to talk about).  Today is one of those since it addresses a question that gets asked fairly frequently.   And having officially released my Nutrition for Injury Recovery e-book, it’s time to finally get around to it.

That question has to do with what kind of calorie surplus is optimal for muscle gain.  That is, people continuously ask what kind of daily, or weekly, or monthly surplus is required to optimize muscle gain and hopefully avoid excessive fat gain.  And, at long last, having run out of podcasts to post links to for a bit, I want to address that question. Now I have mentioned this at least obliquely in earlier articles, primarily the one on the energy balance equation but I want to look at it more comprehensively here.  Basically to examine the factors that determine the actual calorie numbers that we are looking at for gains in muscle mass.

I want to make it clear that these numbers are not perfect.  Actually pinning down good values for them has been a long-standing problem although there are some decent estimates, based on what limited literature is available, along with some rough estimates and practical experience that can give insight.

I will only say as a preview of what I’m going to talk about in detail that the size of the surplus needed to damn near maximize muscle gain while avoiding excessive fat gain is a lot smaller than most people think.  Almost depressingly so.  Let me first briefly re-examine a slightly different question.

Maximal Rates of Muscle Gain

In a previous article, I examined some different models on maximal muscular gains and at least two of those included at least some estimates on what kinds of gains per year or per month might be realistic.  The primary one I want to focus on is the model that, so far as I can tell, was developed by Alan Aragon (aka The Smug One) although I’ve seen it presented in Eric Helm’s excellent and highly recommended Muscle and Strength Pyramid books.  Basically I’m not sure who created it even if I attributed it to Alan originally.  No matter.  I’ve reproduced the model below.

Category Rate of Muscle Gain (Men)
Rate of Muscle Gain (women)
Beginner 1-1.5% total body weight/month 0.5-0.75% total body weight/month
Intermediate 0.5-1% total body weight/month 0.25-0.5% total body weight/month
Advanced 0.25-0.5% total body weight/month 0.125-0.25% total bodyweight/month


I’ve shown rates for both men and women and you can see that, on average, women’s are about half that of men.  This is at least within shooting distance given differences in physiology, hormones, etc.

Within the context of defining categories, I’d say that a beginner is someone training and eating effectively for their first year of training, intermediate might be the next 2 years and advanced is anything past that.  Basically after three years of proper productive training, you’re going to be gaining 3/5ths of jack squat per month.

Let me also point out that the above values represent muscle gain but that the total weight gain per month will be higher than this since it’s nearly impossible (or at least rilly rilly difficult) to gain muscle without any fat gain.

Putting the Muscle Gain Numbers in Perspective

So let’s put the above values in perspective for a theoretical lifter across his training career.

He will start at 140 lbs and can expect a rate of muscle gain of 1-1.5% of that per month for the first year.

140 lbs * 0.01 = 1.4 lbs/month
140 lbs * 0.015 = 2.1 lbs/month

Let me note that my model of muscle gain is based on an average of 1-2 lbs/month (20-25 lbs/year) for a beginner which is right in shooting range of the above.    Let’s say he manages 1.5 lbs/month for the entire year (18 lbs/year) and ends up at 158.  Assume he dieted any fat gain off at some point.

Now he’s in the intermediate stage and things will slow down to 0.5-1.0% gain per month.

158 lbs * 0.005 = 0.8 lbs/month
158 lbs * 0.010 = 1.5 lbs/month

In my original model I allowed for around 1 lb/month so this is still right in range.  To keep the math simple, say he gains 1 lb/month or 12 lbs/year putting him at 170 lbs (again he dieted the fat off).

Now he’s advanced and is doing well to gain 0.25-0.5% per month.

170 lbs * 0.0025 = 0.4 lbs/month
170 lbs * 0.005 = 0.8 lbs/month

Again keeping the math simple, let’s call it 0.5 lbs/month and that’s another 6 lbs/year to reach 176 lbs.  At which point he’s done growing much and any gains will be a crawling amount until he reaches his genetic muscular potential.

But collecting those values, we’re looking at monthly rates of weight gain of

Level Gain
Beginner 1.5 lbs/month
Intermediate 1 lb/month
Advanced 0.5 lbs/month

Ok, so what?

How Many Calories Does it Take to Gain Muscle?

To make the above values of any use, we need to have at least a rough idea of how many calories it takes to build a pound of muscle.  As I mentioned above, this is a more difficult question than you’d think to answer.  I’ve been looking for a good value for years without much luck.  One fairly obscure little exercise physiology book of mine threw out a value and this seems to scan with real world experience and I’ll be using that below.  Before I get to that.

First let me mention that if you break down a pound of muscle for energy, it only provides about 600 calories.  That pound of muscle is about 120-125 grams of total protein, a good bit of water, some glycogen, intramuscular triglyceride (IMTG) and cellular machinery.  Break it all down and it provides about 600 calories.

And this has led to some truly stupid ideas.  The first is that, if a pound of muscle only provides 600 calories to the body when broken down you only need 600 calories extra to synthesize that same pound.   This is then mathed out to a supposed deficit and it ends up being trivial.  One pound of muscle per month would be 600 calories over maintenance, over 30 days and that’s 20 calories per day.  Sorry no.

Tangent: Similarly, the fact that a pound of muscle only contains about 125 grams of protein has been used to draw some very stupid conclusions.  One of which being that you only need that excess of protein to build that same pound of muscle.  By the same logic, if you can build one pound of muscle per month, you only need 125 grams of protein per month extra which is 4 grams of protein above the DRI.  This too is nonsense and assumes, wrongly, that one extra gram of protein is all that is required to lay down on gram of muscle protein.  But nothing in the body is 100% efficient and this no different.  Again, finding exact values is tough but it probably takes 5-8 grams of dietary protein to provide 1 gram of protein per day.  I digress.

So what is the actual value? Again, it’s hard to say but 2400-2700 calories per pound of muscle seems to be within shooting distance . That’s what my obscure little exercise physiology book threw out (sadly, no reference was provided) and discussion with Eric Helms sort of backs that up.

Now, the reality is that it’s very rare to gain 100% muscle no matter what you do.  This gets into the issue of calorie partitioning that I don’t have space to get into here.  Just accept that it’s damn near impossible and the goal is to simply limit fat gain.  Based on some fairly solid assumptions, Eric uses the rule of thumb that to gain a true one pound of muscle, accounting for fat gain, will take about 3,500 calories over maintenance.   I’ll use that value going forwards.

A Note to the Nitpickers

While I’m not going to detail it, let’s all be adults here and assume some basic stuff.  The first is that the person is involved in proper resistance training.  I mean, dadoi.   This isn’t just a case of “Overeat and gain muscle” although some proportion of weight gain usually is in the form of lean body mass even without training.  Let’s also assume that the diet has sufficient protein in it.

If this seems like pedantry, it’s because I’m used to pedants reading my articles and making utterly stupid criticisms of “Oh I guess Lyle thinks this works without resistance training, or that you can eat 100% carbs and grow”  And I just want to cut off the stupid at the pass for all the good it usually does.

Back to Muscle Gain Math

Ok, so now I’ve presented some relatively reasonable rates of muscle gain for a male trainee throughout three different phases of training.  Along with this I provided a rough value of calorie surplus per pound of muscle (assuming some fat gain).  That means multiplying the rate of muscle gain times the surplus to determine the total monthly surplus that should support that rate of gain.  Time to get sad and think about death or something.

Level Gain Surplus/Month Surplus/Day
Beginner 1.5 lbs/month 5250 calories 175 calories
Intermediate 1 lb/month 3500 calories 120 calories
Advanced 0.5 lbs/month 1750 calories 60 calories

Surplus per day was calculated by dividing the monthly surplus by 30.  And you can see that the numbers start out fairly low and drop to damn-near inconsequential.  Hell, 60 calories/day is probably within measurement error on most foods for all but the most neurotic.  But it amounts to almost nothing.  Throw in an extra piece of fruit or protein drink and there’s 100 calories.


But that’s what the numbers work out to.    And, of course, they are even more depressing for women given the realistic weight gains that are possible.    An advanced 130 lb woman gaining 0.25% per month is gaining 0.3 lbs muscle/month.  At 3,500 calories that’s 1050 calories per month or about 30 calories over maintenance.   What I’m saying is do NOT GFH ladies.

Let me make a quick note that it is not uncommon for some people to find out that they need much higher calorie intakes than the above to gain at any appreciable rate.  These are often the skinny ‘hardgainers’ and this is probably due to the fact that Non-Exercise Activity Thermogenesis (NEAT) often ramps up as calories go up.

Basically they burn off the excess calories through excess activity which means that the energy needed for muscle growth isn’t there.  So they may end up chasing their tail a bit as higher calories drives NEAT which means higher calories are needed, etc.  They invariably stay lean easily because of this but weight/muscle gain becomes a problem.   But this is an individual thing.

Final Questions About Muscle Gain Math

There are invariably a few followup questions that come out of the above.

The first is whether the surplus should be eaten every day or only on workout days.  So let’s say our intermediate guy is training 4 days/week.  Should he eat 120 calories per day extra or 240 extra on training days (and maintenance on the other days)?   While you could probably argue this both ways, the time course of protein synthesis, going up after several hours and then peaking at 24 hours (this is often less at the advanced stages) would suggest that keeping calories above maintenance on both days would be the overall better choice.

The second question that comes up, and this is really the important one is what impact larger surpluses will have.    And the answer is that you’ll just gain fat faster.  The reality is that the rate of muscle gain is pretty limited (by things like genetics, hormones, etc.) and just eating more won’t push that to higher (or much higher levels).   Which means that the extra calories either have to be burned off (i.e. via increased NEAT as I mentioned above) or stored as fat.

Basically, you can’t force feed muscle growth and, as Eric Helms so succinctly puts it “Sufficient calories are permissive for muscle growth, not causal.”  More calories does not mean more muscle, it just means more fat.

In this vein is a fascinating study by Garthe (who has done work on elite athletes and body composition).  In it athletes were either given nutritional counseling or to eat ad-libitum (basically without control).   The nutritional counseling group ended up eating significantly more than their maintenance (about 500 calories/day extra) while the ad-lib group was actually damn close to maintenance.

And while both groups gained similar amount of lean body mass (1.7-1.2 kg for counseling vs. ad lib group which wasn’t statistically significant), the counseling group gained 1.1 kg of fat compared to 0.2 kg for the ad lib group).  Even if we assume that the difference in LBM was significant, they only gained 0.5 kg (1 lb) LBM more while gaining about 1 kg (2.2 lbs) extra fat.

Summing Up Muscle Gain Math

And that’s one more topic checked off that I have been meaning to write about.  Basically, despite the idea of massive calorie intakes to gain muscle, the reality is that the amount needed on a daily or even monthly basis is quite small.  Depressingly small given that it’s no fun to have to still count calories meticulously when you’re gaining.

It would be far more fun to just eat a pint of ice cream with protein powder (or McCallum’s awesome Get Big Drink) but the reality is that, unless you’re the typical hardgainer who just ramps up NEAT, all that will happen is that you’ll gain fat at an accelerated rate.  And that fat has to come off at some point.  With the more excessive fat gain meaning that much longer of a diet to get back to reasonable levels of leanness.

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