In this series, we explore the importance of maintaining your fitness level as life goes beyond 40 years. Factors like mobility, muscle mass, and recovery are all important issues we’ll be addressing, and one of the most burning questions people have when they get older is whether our metabolism is slowing down. or not.
For # BeFitOver40, M&F spoke to fitness expert Adam Sutton, who holds an MSc in Sports and Sports Nutrition from the University of Coventry, England. We asked him the important questions about whether or not our metabolism slows down as we age, what factors may be influencing this, and the possibility of turning things around.
Does your metabolism slow down with age or is this just a myth?
Skeletal muscle is more metabolically active than other tissues in the body, which means muscle consumes more calories at rest than other tissues (source:). Typically, as we age, people experience a reduction in muscle mass, known as muscle atrophy, and body fat gain. âThis can be a contributing factor to a potentially slower metabolism during aging,â explains Sutton. “But several studies have compared the resting metabolic rate of younger and older individuals, while controlling fat-free mass and body fat, and younger participants have been shown to have higher resting metabolic rates, as well. As the loss of muscle mass that occurs with aging, the remaining muscle also becomes less metabolically active as we age. Luhrmann et al completed a study in 2009 on the elderly, to investigate the effects of aging on metabolic rate. The results once again showed that participants gained body fat and reduced lean mass as they aged, despite no change in their overall weight. The results showed that the resting metabolic rate of subjects decreased by 5% per decade in males and 3% in females.In addition, physical activity levels have been shown to decrease at a rate. 7.5% rate per decade for men and 6% for women. “Overall, the results of these studies support the claim that metabolism slows down with age,” explains Sutton. “But there are other factors at play.”
Many people say that they cannot help being overweight because they suffer from slow metabolism. Is it right?
âI would say to a certain extent, and under certain circumstances it is true, however, there are many more factors that contribute to an individual’s overweight,â says Sutton. He points out that certain conditions, such as a mutation in the KSR2 gene can promote obesity, however it is our energy balance that is the determining factor of our weight. Excess food intake is usually the main contributing factor to our being overweight, which then slows down our metabolism. As explained, reducing fat and increasing muscle will likely do wonders for our metabolic rate.
Do some people have a faster metabolism than others, even though they are the same age?
âYes,â Sutton said. “Basal metabolic rate is the biggest contributor to an individual’s total energy expenditure.” Basal rate is the number of calories needed by the body to function while at rest. Sutton also explains that thyroid issues can affect metabolism and that our individual genetics will play a role, as will our activity levels. But again, those with more mass without fat are likely to have a faster metabolic rate.
So how do we speed up our metabolism?
âChanging our body composition to increase muscle mass and reduce fat mass would be beneficial,â says Sutton. “This can be done through resistance strength training and by ensuring that the energy intake through calories is not too great to cause the build-up of fat mass.”
However, Sutton points out that reducing our energy intake will also cause the body to adapt and learn to function on fewer calories. One study showed that skipping breakfast had no direct effect on metabolic rate, but may result in participants expending less energy throughout the day, possibly due to lack of fuel.
When energy intake is low, the body will start to deplete its stores of carbohydrates and fats and it will then look for alternative stores to support the metabolism. Under extreme circumstances, the body will use the amino acids in proteins to derive glucose for metabolism. This protein comes from muscle and is broken down to produce energy, resulting in reduction in muscle mass and further reduction in the individual’s metabolic rate.
Extreme crash diets can therefore cause more harm than good. They are not long lasting and can also lower an individual’s metabolic rate. Additionally, this approach will more than likely lead to weight gain in the future. Restricting food intake too severely will also put individuals at risk for deficiencies in other food components such as vitamins and minerals, which is also detrimental to metabolism and bodily functions. The safest and most sustainable way to lose fat mass is a moderate calorie restriction diet combined with increased energy expenditure through exercise which promotes muscle mass gains.
Although we need to control our calories, cutting them too hard or dieting heavily is not the solution. âThe increased training and our ability to withstand higher exercise intensities will speed up the metabolism,â explains Sutton. âAfter exercising at 75% VO2 max for 50 minutes, energy expenditure is 6 to 15% higher over the next three hours than at rest. Therefore, more intense physical training will speed up the metabolism of an individual.
So there you have it, it’s fair to say that metabolism slows down with age and we all have different metabolic rates due to various factors, but that’s probably an excuse to say that our metabolic rate is holding us back. , when it can be improved through a sustainable calorie diet and increased muscle mass through exercise.