Contrary to what is sometimes stated, muscles cannot “turn into flab” any more than fat can turn into muscle. The two are entirely different tissue.
So what is the difference between muscle and fat? Plenty! But I’ll list those that matter to you and me. Keep in mind I am not making a statement about preference for muscle or fat, just offering several physiological facts:
- Muscle is dense and shapely
- Fat is bulky and shapeless
- You can actively contract muscle
- Fat jiggles
- After genetics, muscle is 100% determined by activity (type, severity, and frequency of the stimulus)
- After genetics, fat is 100% determined by long-term fuel balance (fuel absorbed – fuel expended)
- After puberty and initial training growth, muscles do not increase or decrease dramatically in a short period. The exceptions are injury or steroid use.
- Fat can increase or decrease dramatically in a short period
- Muscle burns around 5-6 calories per pound
- Fat burns around 2-3 calories per pound
- Muscle contains a high percentage of water
- Fat contains very little of its weight in water
- Muscle gives you power
- Fat is dead weight
- Muscle is proportionately distributed throughout the body if you’re following a balanced training program
- Fat is stored mostly around the middle
- Muscle makes physical labor easier
- Fat makes physical labor harder
- You can isolate and train specific areas of muscle
- You cannot isolate specific areas of fat (i.e. spot reducing)
Here are four additional myths dispelled:
1. Muscle doesn’t “weigh more than fat” (does a pound of bricks weigh more than a pound of feathers?). Muscle is more dense than fat, but not by much.
2. Muscle doesn’t fluctuate as much as fat. Muscle atrophy (loss) or hypertrophy (gain) is not easy to achieve on large levels; however it is possible to lose a lot of fat in a short time (though not easy) or gain a lot of fat (easy). What fluctuates more wildly than both? Water.
3. Excess calories do not build muscle. Excess calories do build fat.
4. Exercise is not necessary for weight loss. Exercise is very important, but even if you slept all day, all the major organs of your body would still need fuel. However, exercise contributes to your energy deficit, increases functional capacity, improves your shape, enhances your mood and makes dieting easier.



Common gym lore is that adding muscle mass is important while losing fat because “muscle burns more calories than fat”. While this is true, the numbers are insignificant. 1 pound of dry muscle burns about 6 calories while 1 pound of fat burns approximately 2 calories. Considering that the protein content of muscle makes up a small percentage of its total volume (muscle is mostly water), adding 5-10 pounds of dry muscle is significant for any non-drug using trainee. This amount would also require consistent hardcore training.

