Will My Fat Turn into Muscle? Can My Muscle Turn into Fat?

Will My Fat Turn into Muscle? Can My Muscle Turn into Fat?

I’m here to do a spot of myth busting with you here on the Plus Size Fitness Melbourne blog today. As a personal trainer, I hear people talking all the time about their muscles turning to fat if they stop exercising or their fat turning into muscle if they start doing weights.

This is absolutely a myth. Why? Muscle and fat are physiologically different substances. It’s just not possible for one to morph into the other. It’s a bit like an orange can’t turn into an apple – they may both be fruits but they can’t turn into one another – they are different things.

So why do football players, for example, often gain weight and lose their muscle once they retire from playing footy? Elite athletes typically follow very specific regimes when it comes to their physical training and their nutrition to optimise their bodies to be the best they can be for their sport. When they retire, they generally will no longer train at the same intensity and they will likely relax a bit on the food front as well (or don’t adjust their food to take into account their new activity level).

Athletes, such as footballers in this example, tend to be quite muscular. Muscle is much more metabolically active than fat is which means that 1kg of muscle will use up more energy (or calories) than 1kg of fat will just by existing – all day every day. If you stop using that muscle though, it will start to atrophy or waste away which will often happen to athletes who no longer train at the same intensity as they once did. It’s not all going to disappear suddenly but over time, if it’s not trained as hard, it will become smaller and not as strong as it once was.

Because they have lost some of their energy-burning muscle, they will need to adjust the amount of food they are consuming to maintain their weight. They just aren’t burning the same amount of energy with their decreased muscle mass. They need to consume less energy to accommodate this. If they continue eating how they always have, or relax the ‘rules’ they’ve always followed for their dietary requirements a bit, they will likely find they are taking in more energy than their body can burn up during the average day.

If they are not using this excess energy, it will begin to be stored as fat. So what is happening? Their training load has decreased so their muscles mass is decreasing as well. They are starting to consume more energy in their diet than their body can use up so it is being stored as fat. Their body composition is changing. They have less muscle and they have more fat. However, their muscles isn’t physically morphing into fat.

It works both ways. If an overweight person started training and starting to get leaner and their muscles were getting bigger and stronger – their fat isn’t morphing into muscle. They are working their muscles more and developing its size and strength. They are using more energy by having this increased muscle (as well as from exercising more than they were in general), some of their fat is being used for energy as they are quite likely taking in less energy than their body needs to function at that point in time.

Hope this clears up the muscles turning into fat question a bit for you. Before too long, I will be back with another post about the other muscle/fat question we get asked a lot. Does muscle really weigh more than fat? This one goes a long way to explaining how you can weigh the same (or more) and lose centimetres with the tape measure.

Still confused? Make sure you pop by our Facebook page for a chat and we’ll try to explain it in another way 🙂