Have you ever dedicated yourself to a transformation challenge? The kind where you sign up for 30 days of cardio, food logging, burpees, whatever! Inevitably during the challenge you step on the scale only to see that it has creeped up during all your hard work, not down. WTF! Some well meaning friend or family member has no doubt said something to you like, “don’t worry, that’s probably mostly muscle” or “Muscle weighs more than fat.”

In terms of body composition change, muscle gain actually happens painstakingly slow. It can be totally reasonable to lose 8 lbs of fat over a 12 week period. But gaining 8 lb of muscle? That is a different thing entirely. Let’s talk about why and what is actually happening.

Muscle is $$

While attempting to put on muscle certainly can cost more dollars in the grocery store, what I mean is that muscle is calorically more expensive to maintain in the body. Just 1 pound of muscle on the body can burn 7-10 calories per pound just by existing on the body. By contrast, 1 pound of fat only burns about 2-3 calories. So having 10 lbs of muscle on your frame can burn an extra 70-100 calories per day, vs 10 lbs of fat only burning 20-30 calories. You can see where I am going with this.

Example: A 150 lb female with a body fat of 20% has approximately 120 lb of Lean body mass; Muscle, bone, ligaments, tendons, etc.

150 lb female with body fat of 30% has only 105 lb of lean body mass.

If the difference there is 15 lb of fat between the two, then the more lean individual is actually burning up to an extra 100-150 calories per day just by existing. That may not seem like a lot for a single day, but adding that up over weeks, months, and years can start to have some pretty big implications on health and physique.

So over the course of say a 30 day challenge, if you are seeing the scale move up more than normal, chances are good you may be gaining some muscle. But careful not to think that it’s all muscle. If it seems too good to be true, it probably is.

You need to eat more.

You know how those magical transformations promise that you will lose fat and tone up all at once? I’m not saying they are complete BS, but they certainly are overpromising. The concept of losing fat requires your body to be in a caloric deficit. Without it there is no way to lose body fat. Period. I don’t care if you are eating 5,000 extra calories of broccoli (good luck) or 5,000 extra calories of Oreos. Excess = excess.

In the same manner, putting on muscle requires you to be in a caloric surplus! If you want to grow your muscles, you are asking them to get bigger, you must feed them! You wouldn’t plan a flower and expect it to grow without water and sunlight! Your body is the same. In order for it to grow it requires food, water, nutrients, and strength training. So if you are in a challenge where you are eating less food and hoping to gain muscle…. I’m just going to let you connect the dots on this one.

So, how much muscle can I gain?

This one is going to get a little tricky, the answer is always it depends. Complete beginners will have a better chance gaining muscle from a wider variety of exercises as they have more ground to make up. In general the longer you have been training the more effort it takes to build muscle. Beginners can gain up to 10% their body weight in muscle (so for someone 150 lb, theoretically could gain up to 15 lbs of muscle over the course of a year.) However, if you have been training with weights for a while and already have a healthy body fat percentage, your muscle gain percent drop closer to the 5% range over the course of a year. Notice I said a year here. Fat loss may be able to be measured in weeks, but any noticeable amount of muscle will take months if not years.

Before you run out and start eating exclusively chicken and rice in an effort to muscle out, let’s talk about something called the “P ratio.”

Change in fat-free mass ÷ change in total body mass = p-ratio

This principle indicates that for any change mass, some will be stored as lean tissue (muscle) and some will be stored as reserves (fat.) It is likely that individuals with a low body fat percentage are able to have an easier time gaining lean tissue (high p ratio), and those with excess fat store more mass as fat tissue (low p ratio).

For this, and a few other reasons I generally tell people that unless they are okay seeing the scale move up (cuz it will) and gaining a little bit of fat that can be cut later, they are not ready for a muscle gain diet specifically.

If it’s not muscle…

I’m gonna make a lot of people mad when I say this…

When the scale has small, irregular bumps in it, and you’re training pretty hard here are a few things it can be, that are not muscle.

1. Inflammation response- When we work out we are actually creating damage to our muscle fiber, breaking it down. The building up process actually takes place during our recovery time! During the repair process inflammation comes into play, increasing blood flow to the area to replenish oxygen, fuel muscles and clear out waste. Before you panic, this inflammation is not only necessary for the muscles repair process, it is actually GOOD to help the muscles acclimate to the work demands we have placed on them. This inflammation can often read as a jump in the scale. So before you freak out after stepping on the scale the day, think about if you had a hard work out the day before. Chances are your weight will be up a bit.
2. Hormones (your period, ladies)- We tend to hold water toward that time of the month. And ultimately that weight reads as a gain on the scale. So until scales account for things like cycle fluctuations, don’t make any sudden moves in diet or exercise around this time!
3. Tissue – If you are tracking your weight pretty regularly and your average weight is steadily increasing every week…that my friends is a tissue gain. Some may be muscle, and some may be fat. Your training and your diet are the biggest components of which it may be.

When we are seeing BIG, upward trends in something like scale weight over the course of a month or two, you could be gaining muscle, but even if you are – you are probably gaining a little bit of fat too.