Muscle: The Engine Behind Our Metabolism

As we age, many of us tend to gain weight. But have you ever asked the question ‘why’? The simple reason is that, aside from lifestyle factors – such as declining activity levels – our muscle mass actually declines. This holds the key to unlocking the ‘secret’ to weight loss.

Since muscle is one of the major factors driving our metabolism, the side-effect of muscle decline is obviously a slower metabolism meaning weight gain over time. Research shows that this process starts as early as age 30, and that a woman can lose up to 15 per cent of her total body muscle by age 50. This age-related loss of muscle mass, strength and function is known as ‘sarcopenia’. People who are physically inactive can lose as much as 3 to 5 per cent of their muscle mass per decade after age 30. So the average 40 year old woman may have already lost an incredible 10 per cent of her muscle mass if she isn’t careful.

What’s the Good News?

Thanks to recent knowledge regarding muscle mass and metabolism, weight gain as we get older could be more manageable than we think. Once we understand what sarcopenia is, we can do something to counteract it. The key is to exercise, particularly focusing on strength or resistance training, whilst also maintaining a regular intake of high quality protein.

Discovering this is the reason that, three years ago (when I hit 40) that I decided to start going to a personal trainer. Since then, I go once a week (sometimes topped up by a second session) at the brilliant Kiwi Fit. Since then, I’ve noticed that maintaining my weight has become much easier, along with following the Motivation way of eating; which is a plan that focuses on regular, quality inputs of protein and lower, better quality carbs, a limited amount of fruit and an abundance of fresh vegetables.

Exercise: What Type is best?

Becoming less active is the worst choice to make when it comes to warding off sarcopenia. We need to be especially careful as we age that – if at all possible – activity doesn’t decline. If it does, we are guaranteed to see our metabolism slow down and our weight go up.

“Without question, exercise is the most powerful intervention to address muscle loss, whether it occurs in the context of advancing age or debilitating chronic or acute diseases,” said Nathan LeBrasseur, a physician from the well-regarded Mayo Clinic in Minnesota. Exercise is recommended on most days of the week, but a minimum of three times per week is recommended to slow muscle loss and prevent sarcopenia.

Also, it’s useful to know that, after a strength training session, your metabolism actually stays elevated for a period of time thanks to a process called EPOC (commonly known as ‘the afterburn effect’). This refers to all the oxygen (and energy, in the form of calories) that your body uses after exercise in order to help your muscles recover. Incredibly, research suggests that this process can go on for anything from 12 hours to a few days, depending on the workout and who is doing it. Strength training is especially effective at raising EPOC because, generally, it causes more physiological stress to the body compared to cardiovascular exercise. That explains why particularly intense strength exercises – like squats, deadlifts and bench presses – are much more effective at raising EPOC compared to bicep curls or tricep extensions with light weights.

Where do I Start?

Consider weight-lifting once a week to begin with. Then, ideally build to two to three times a week. If twice a week is the maximum time you can spare right now, that’s fine (even once per week is better than nothing). It’s important to use weights that are heavy enough to exhaust your muscles with 12 repetitions, yet light enough to complete eight comfortably.

Besides an improved metabolism and improved fat burning, there are countless reasons to lift weights and build strong muscles, including injury prevention, improved bone density, feeling more toned, enhanced memory (yes, you read that correctly) and a lower risk of type 2 diabetes. Get advice from a personal trainer or local gym to get started and don’t be turned of by thinking you’ll look bulky – it’s a myth. The look is strong and fit, rather than bulky. If the gym just isn’t for you, consider pilates, yoga or aquafit, which all use the weight of your own body for resistance.

Intake of Protein

Protein is the most valuable food for repairing and building muscle fibres. Studies show that 12 per cent of men and 24 per cent of women aged 70 or over eat significantly less than the recommended 0.8 gram of protein per kilogram of their body weight each day (this could explain, in part, their weight gain). For healthy adults, between one and 1.2 g/kg is a good target for daily protein intake. For those with sarcopenia, protein needs are even higher at 1.2 to 1.5 g/kg a day. At Motivation, all our plans are designed in a way that delivers adequate protein for both satiety and optimal muscle retention (alongside an exercise programme).

What Food Works Best?

When it comes to positively impacting sarcopenia, it’s not just how much protein you eat, but also what type of protein you consume. Not all protein is created equal, and the type of protein you eat also seems to play a role in preventing muscle loss. Dietary protein is made up many types of amino acids. The body can make some amino acids on its own, but the rest it must obtain from protein-rich foods. Of the 20 total amino acids there are, certain ones are considered ‘essential’ because these are the specific kinds we aren’t capable of making ourselves. The amino acid leucine has been shown to preserve body muscle. Leucine is an essential amino acid, which means our bodies cannot produce it, so we must get it from dietary sources. Leucine is found in lean beef, lamb, poultry, fish, eggs, milk and products made with milk (such as cheese). It’s also found in soybeans and other beans, nuts and seeds. Research also shows that eating protein before and after exercise helps increase muscle recovery and promotes muscle synthesis. Ensure you have good quality protein with every meal (and don’t forget fish, especially oily fish like mackerel, tuna and salmon) and in your snacks in-between meals (try protein bars, nuts, hummus, cheese or a pot of edamame beans).

Busting Myths!

There is a big myth out there that strength training can’t build cardiovascular fitness. This isn’t true – if done correctly, it will. Anything that increases your heart rate and respiratory rate will improve your cardiovascular fitness. Doing 10-20 loaded squats will soon show you that you are breathing heavier and your heart rate is up. If you do some interval training and hop onto the cross-trainer for 3 minutes in the middle of your strength session, even better!

Blog Post by Maebh Coyle