D=M/V is a standard representation of the density (D) of a given substance.
In muscle terms, D=F*M/V
Simply put, the density of a given muscle is simply the amount of force a muscle can generate multiplied by the mass (weight) divided by the volume.
Meaning, simply, a stronger, heavier muscle occupying less space will be more dense.
If you increase the amount of weight a muscle can lift (with strict form) without increasing the volume of space it occupies, you will increase the density.
For example, a 21 inch biceps can curl, say, 50lbs, if you increase it's workload capacity to lifting 100lbs without an increase in size (still 21 inches) you will effectively increase the density.
For this reason strong bodybuilders are more dense than weaklings. Ronnie Coleman for example is much (MUCH) more dense than say, oh, Phil Heath.
You can give the ILLUSION of density with drugs, but it has a different look to it than the real deal, so to speak.
This also explains why it is important to increase strength along with size. If you can get bigger without getting stronger, you will LOSE density.
Some confuse muscle maturity with density and I believe this to be a mistake. Muscle maturity is simply a greater proliferation of motor units within the muscle I believe. It happens over time as you recruit motor units and over time they multiply in number, allowing you to recruit more muscle fibers in a given workload. For this reason VOLUME should be kept HIGH when you are starting out and gradually decreased as you get older.
You may look at Jay Cutler as a perfect example of this. He trains high volume and moderate intensity with moderate weight and while he is huge he is hardly dense and his muscles have not changed much in appearance over the years, though he has managed to steadily get bigger.
Branch Warren is a great example of density as proven with the above equation. He has a much smaller frame yet competes at the same weight as guys 5 inches taller. On top of that, he lifts much heavier weight. His muscles occupy LESS VOLUME and yet have more MASS and can move MORE weight than the taller guys, thus his muscles have MUCH MORE DENSITY.
Now, he has always been thick and dense, and I bet he has always been strong, which also proves (to a degree) my point that muscle maturity is NOT the same as muscle density.
Only posting this because I have seen the question posed before "how do you increase muscle density?" and I had never been able to accurately answer it. Now, you have an answer- combine periods of strength training (very low repetitions, around 4-8) with periods of growth training (8-14 reps for most exercises).
Also I believe it is important to use exercises for their best application. Deadlifts, squats should be kept low repetition (deads down to 2 reps, squats down to 4). An exercise like, say, cable crossovers should be used for 10-16 reps. Leg extensions 10-20 reps, while barbell rows 8-12 etc etc. You get the point, I hope.
Hope this helps.
MM
