FITNESS ASSESSMENTS

Percent Body Fat (Body Fat Percentage)

Percent Body Fat is always expressed, obviously, as a percentage. This percentage can then be applied to set percent body fat ranges. While there are no official, set-in-stone ranges like there are for BMI, you’ll find that the healthy ranges tend to hover around 10-20% percent body fat for men and 18-28% for women. Organizations offering set ranges include ACSM and ACE; you can view theirs as well.

Lean Body Mass (aka Fat-Free Mass)

Another very important term to be familiar with is Lean Body Mass, sometimes used interchangeably in conversation with Fat-Free Mass.  As that term implies, Lean Body Mass is the weight of everything in your body that isn’t fat. This includes your muscles, organs, bones, and body water.

Lean Body Mass plus your Body Fat Mass makes up your entire body weight. If you have your Lean Body Mass value in pounds, you can subtract this number from your total body weight to get an approximation of your Body Fat Mass. Divide that by your body weight, and now you’ve got your percent body fat.

Skeletal Muscle Mass

When people talk about their muscles, they’re more than likely talking about Skeletal Muscle Mass.  Skeletal muscle is one of the three major muscle types (the others being cardiac and smooth) and is the type that governs all the movements you can consciously control: everything from typing out a text to deadlifting a 300-pound barbell. It’s also the muscle group you’re growing when you exercise.

Muscle isn’t just for strength.  Muscle is composed of primarily protein and can act as a “protein bank.” Why would you want a protein bank? When your body gets put under severe stress – such as in a traumatic injury – the recovery process is triggered and requires additional protein, up to four times the amount in some cases. When it’s not able to get that amount of protein from your diet, your body will start getting what it needs from the protein bank – aka your muscles.

Basal Metabolic Rate (BMR)

Your Basal Metabolic Rate, or BMR, is the number of calories that your body requires to maintain its Lean Body Mass. It’s a huge component of your overall metabolism.  Someone with more Lean Body Mass will have a higher BMR than someone with less BMR. It’s the reason why a 250-pound NFL linebacker needs to eat more than a 150-pound sedentary adult – the linebacker has far more Lean Body Mass.

Value To You: Outside of your Percent Body Fat, if you learn a second thing today, learn the value of your Basal Metabolic Rate.  Used properly, your BMR can help you make a nutritional plan designed for either fat loss or muscle gain by helping you understand how much energy (read: calories from food) your body needs.

By multiplying your BMR with an activity factor, you can get a general estimate of your Total Daily Energy Expenditure (TDEE). Using your TDEE as a baseline, you can start to craft nutritional plans for yourself based on what you want to do with your body composition.

Want to lose fat? Create a caloric deficit by decreasing energy in (food) and increasing energy out (exercise). Looking to increase muscle? Eat more than your TDEE requires and use that extra energy to hit the weight room and build new muscle.

Body Water

You may have heard somewhere along the line that “humans are mostly water.”  Generally speaking, that’s true. Your Body Water includes all the water in your body, everything from the water in your blood, to the water in your organs, to the water inside your bones.

Your body water is usually subdivided into two types: intracellular and extracellular. Intracellular (inside the cells) includes the water in your organs, muscles, and such, composing 2/3 of your total body water. The remaining 1/3 is the extracellular (outside the cells) water and includes the water in your blood.

Dry Lean Mass

Lean Body Mass contains body water, and your body water levels can be influenced by many different factors: whether you’ve recently worked out for instance, or whether you are low on carbohydrates. Changes in body water are technically changes in Lean Body Mass (another reason why Lean Body Mass isn’t the same as muscle).

However, when you build muscle, you’re actually building new physical protein stores – and that’s reflected in your Dry Lean Mass. An increase in Lean Body Mass may signal muscle growth, or it may not. By contrast, an increase in Dry Lean Mass is a much stronger indicator that you actually grew muscle.

Visceral Fat

There are two major categories of body fat. Subcutaneous fat is the fat under your skin, and it’s the type of fat that you can see.  The second type of fat is called visceral fat. This type of fat collects inside your abdomen and wraps around your internal organs.

The more visceral fat you have, the greater risk of inflammation. Inflammation over time can put undue stress on the heart, leading to cardiovascular problems later on.