Don't worry - stopping exercise won't turn muscle into fat

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You might have been warned about this as a child: always stay active otherwise your muscles will turn into fat. But nothing could be further from the truth. The good news is, if you don't work out, your muscles will not transform into fat, simply because the two have completely different functions and are made up of completely different types of cells.
"Skeletal muscles are needed to maintain your posture, facilitate movement, and perform fine motor activities, such as writing and painting," says Joan Liew, co-founder and director of Fitness Factory in Singapore.
"Your muscles are made up of protein and are connected to your nervous system by neurons. Your stored fat or adipose tissue, on the other hand are made up of fat cells called adipocytes.
"The size of your fat cells increases when there is an accumulation of fat through an uptake of fatty acids into the adipocytes.