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Santa Clara, CA
A 56-year-old female asked:

Why does bmi increase when one starts weight training and replacing fat with muscle mass? weight increases while becoming leaner, but bmi increases?

1 doctor answer3 doctors weighed in
Dr. Marlis Gonzalez fernandez
Physical Medicine and Rehabilitation 15 years experience
Not perfect!: Bmi only takes into account weight and height. That is good enough for most people but for people that exercise a lot and have a lot of muscle it is not a good reflection of their actual fitness. Muscle weighs more than fat so the bmi can increase even though you are in better shape. Most pro athletes have bmis that are in the "wrong" range. Worry about your overall health and not the number.
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Last updated Sep 28, 2016


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