Myths around metabolism abound: “Coffee speeds it up!” “It slows down after the age of 40.” “Lifting weights raises your basal metabolic rate.”
It’s not uncommon for supposed health foods and diet plans to claim they “boost metabolism,” but more often than not this is simply confusing false advertising.
So how much of what we hear is actually true? Why do our metabolisms differ and is there really anything we can do to change ours?
Here’s everything you need to know about metabolism - and how to improve yours:
What is metabolism?
Put simply, metabolism is the process by which our body converts food into energy. The body takes the calories from what we eat and drink and uses oxygen to release the energy we need to function.
Why would you want to raise yours?
The higher your metabolism, the more calories you burn at rest. So if you’re trying to lose fat, increasing your metabolism is a huge help. But by following the steps needed to boost yours, you’ll improve your energy, skin tone and mood too.
Is it actually possible to change your metabolism?
Yes! Everyone can optimise their body to make it use fuel most efficiently, and the best way to do this is through exercise.
How to boost your metabolism
To rev your metabolism as much as possible, you want to be combining high intensity workouts to burn fat and resistance training to build muscle: “Muscle is much more metabolically active than fat and someone with a higher volume of lean muscle mass has a more efficient metabolic rate,” Israel Rivera, Head of Group Exercise at Virgin Active, explained to The Independent.
If you want to lose fat, it’s generally believed that the best way to do this in the long run is through strength training - ie lifting weights. “Broadly this is because resistance training stimulates muscle growth and the greater the muscle mass, the higher the rate of metabolism required to keep that muscle operational,” Dr. Ben Kelly Head of Preventative Medicine at Nuffield Health, told The Independent.
“That is not to say that aerobic training is not effective in augmenting metabolism - the best results tend to occur when both exercise types are used.
When it comes to cardio, you should be trying to raise your heart rate to 120 to 140 beats per minute for 20 to 35 minutes - but not go over 145 beats per minute, according to author of Metabolism Revolution Haylie Pomroy, who has worked with clients such as Jennifer Lopez and Reese Witherspoon.
As well as cardio workouts, try and do two weights sessions a week. “Work with stacked reps in sets of three,” Pomroy told Well + Good. “Start with eight reps, then six reps, then four reps. The weight should be heavy enough that you can just complete the reps to muscle exhaustion.”
Eating plenty of protein at every meal - not just post-workout - is essential because the amino acids are used for building lean muscle mass.
Rivera also recommends drinking more water: “People who drink more water have a higher metabolic rate and higher success rate for achieving their fitness goals.”
And despite what you might have been told about how to lose weight, eating regularly is key, and ideally within 30 minutes of waking up. If you don’t eat before leaving the house and starting your day, your body can go into panic mode - “Your adrenals will produce [cortisol], an emergency hormone that tells your body it had better start stockpiling fat, because who knows when you’ll get more food,” says Pomroy.
Studies show that eating roughly every three hours, whether a meal or a snack, keeps your metabolism up over the course of the day. Don’t be tempted to cut calories drastically, as this can lead to metabolic slowdown.
As if we needed another reason to treat ourselves to a weekend lie-in, Rivera says getting more sleep can have a positive effect on your metabolism too: “Sleep deprivation can have a negative effect on achieving your fitness goals as being tired increases stress hormones,” he says.
“Lack of sleep has also been linked to an increase in blood sugar levels which makes you feel hungry or sluggish which can slow the metabolism.”
Why do metabolisms vary from person to person?
The metabolism is personal to each individual and we all metabolise food at different rates. This can be affected by various factors, such as the volume of lean muscle mass on your body.
“A professional athlete would have a much higher metabolism than that of a sedentary office worker,” Rivera gives as an example. “Age, gender and personal medical considerations sometimes also impact our metabolism.”
The more sedentary you are, the slower your metabolism, so it’s crucial to stay active, particularly as you age.
“At the end of the day, exercise will always have a positive impact on our metabolic rate and overall wellness,” Rivera says. “Good nutrition and regular exercise are gateways to overall health and successfully meeting your fitness goals.”