The Most Accurate Ways to Assess Body Fat and Lean Muscle Mass

Many enjoy a fitness "bulking phase" in the winter season. Getting in the gym and lifting more is a great way to spend the year's colder months. However, gaining weight can go wrong, and you find you are putting on more fat than muscle. But are the tools you use to assess your gains accurate?

That is the big question a reader has about his own weight-gain cycle:

Stew -- Help, I am gaining weight like I wanted to, but after standing on my body fat scale, I saw that I added 10 pounds of fat and lost 5 lbs of muscle. I am taking in 4000 calories a day to gain weight. Lifting 3-4 times a week reduced my cardio to 10 minutes daily. I feel good about my progress, but I feel that something is not right. Thanks, John

With several methods available that track body fat/lean muscle mass, you must understand that not all provide accurate assessments of your body composition. There is a hierarchy of fat assessment tools, and your home scale is likely not high on the accuracy list. Since you mentioned feeling pleased with your overall weight and strength gains, could the discrepancy be the assessment tool and not your progress? Yes, very likely.

The top three that are considered the most accurate are the following:

• According to WedMD and a variety of studies, the DEXA scan is the gold standard, using low-dose X-rays to measure lean muscle mass, body fat percentage and bone density and offering a comprehensive understanding of your physique.
   
• Hydrostatic weighing is another option with high accuracy marks, but it is challenging to find. It requires specialized facilities that use underwater displacement measurements to measure body fat percentage accurately.
   
• Air displacement plethysmography (ADP), known as the Bod Pod, effectively measures body volume with an error range of 1%-2%. This is a good option to measure body composition. (study)
   

At-home assessments, such as the body fat scales utilizing bioelectrical impedance analysis (BIA), skin calipers and the Body Mass Index (BMI) equation are convenient, but they can be significantly incorrect because of factors such as hydration levels and technique. These tend to overestimate body fat percentages and underestimate (or ignore) lean muscle mass.

Ultimately, as you continue your weight gain endeavors, it may be beneficial to consult more accurate body composition measurement methods for clarity. My advice is to keep lifting, start reducing caloric intake to normal amounts (2,000/day) and start progressing with cardio each week as spring approaches. Then you can do a calisthenics and cardio cycle to rip it back up again.

Keep pushing yourself and find ways to train different components of fitness, versus only getting bigger. There are hundreds of articles in the Military.com Fitness Section to help you develop seasonal training ideas to boost your existing workout routines, and you can send emails to stew@stewsmith.com for questions. 

Want to Learn More About Military Life?

Whether you're thinking of joining the military, looking for fitness and basic training tips, or keeping up with military life and benefits, Military.com has you covered. Subscribe to Military.com to have military news, updates and resources delivered directly to your inbox.