PT on the Net Research

Does Muscle Weigh More Than Fat?


I’m starting to hear a lot from clients that muscle weighs more than fat, so when some of my clients weigh themselves, they notice a slight increase (assuming they are building some muscle). I have been told that muscle doesn’t necessarily weigh more than fat, but one is just denser than the other. What is your take on this?


Does muscle weigh more than fat? One kilogram of fat is the same as one kilogram of muscle. The difference lies in the density of these tissues. Muscle tissue is much more dense than that of fat, so therefore the volume or size of one kilogram of fat is much larger than one kilogram of muscle tissue. Weighing yourself on a scale is not a great way to measure improvement in health and fitness levels. Often, a client will be depressed by the fact that he weighs the same as when he started exercising. What this doesn’t tell the client is that while he might weigh the same, his body fat to lean muscle mass ratio has probably changed, which is why he may have dropped a few inches around the waist, chest and legs but his weight remains the same.

Take this for example. A female weighs 65 kilograms when first starting an exercise routine. She has 20 percent body fat (13 kgs). After six weeks of weight training, she weighs herself and still weighs 65 kilograms, but now she has 17 percent body fat (11.05) and has lost five centimeters off her waist measurement. So she has actually lost 1.95 kilograms in body fat but has put on 1.95 kilograms in lean muscle mass.

It is important to educate clients that measuring their weight on the scales is not a true indication or good measure for improvement. Depending upon your clients’ goals, this will help direct you to the best way in developing an array of tests to measure their baseline standards. Other tests commonly used to measure baseline fitness and health levels include skin fold measurements, size measurements of body parts (i.e., waist, trunk, thighs, etc), VO2 max testing and carrying out an initial screening of abilities (strength and endurance are probably better methods to adopt). By adopting a variety of base line tests, you will be able to demonstrate your clients’ improvements in a variety of ways.