Did you know that your metabolism slows down as you age? I am sure you have heard this fact spouted at some point in your life. We may have even found ourselves using this statement as a simple fact of life, as if there is nothing we can do to change the outcome. It can become a crutch where we allow ourselves to justify where we are in life, instead of making a difficult decision to understand why and work to a solution.
I am here to dig a little deeper into the slowing metabolism and ways to combat it!
First let us understand what metabolism is. Metabolism is the process of converting the calories you eat into energy to power all of your bodily processes. Your metabolism determines the amount of calories you can eat all day and still maintain your weight. ItÕs affected by three major things:
1. Basal metabolic rate (BMR): The number of calories needed to maintain your body in a rested, fasting state. ItÕs affected by your gender, age, size, muscle mass, genetics and health-related factors. Your BMR accounts for 60-70% of the total calories you burn each day.
2. Activity level: The number of calories you use up during exercise. Your activity level accounts for about 20% of the total calories you burn each day.
3. Food thermogenesis: Tells you the number of calories you need to digest and absorb your food. It accounts for about 10% of the total calories you burn each day.
Anything that affects the three major things mentioned above would change the amount of calories you need to maintain your body weight. Your basal metabolic rate is adaptable, and it will increase or decrease to provide for your bodyÕs needs.
So why does aging affect your metabolism? Well here is time of that dreaded line, as we age our metabolism slows down, this is normally due to a decrease in BMR. Our BMR is highest during childhood and adolescence, as we need extra calories to support our growth as we mature in to adults. Once we reach our 20s the growth is complete and our BMR levels off, and can start to decline at this time. This is due to weight gain, however not any type of weight gain, but specifically a loss of lean muscle mass that is replaced with fat.
For young adults they are typically composed of about 50% lean muscle mass of total body weight, which often declines to about 25% of total body weight once we hit 75-80 years of age. Having lower lean muscle mass decreases our BMR since pound for pound it takes more energy to maintain muscle vs fat.
Of course I am not telling you to lose all that fluff! We do want to keep a healthy amount of protective fat, especially once we hit those older ages, around year 65 and older. But we do want to maintain as much lean muscle as possible. In doing so it will stop our BMR from declining as rapidly. Preserving your muscle mass will also allow you to continue to stay active and maintain strength and range of motion throughout your aging.
Here are two simple tricks to help maintain muscle and stave off a slow metabolism;
1. Strength training – Even when you are not active your body burns calories. 1lb of lean body tissue burns an average of 14 calories a day where 1lb of fat only burns 3 calories a day.
2. Stay Hydrated (I feel like we say can solve a lot of things, but it never stops being true) – Being even mildly dehydrated can slow down your metabolism, because your body needs water to process calories. The obvious solution is to drink water, but you can also maintain hydration through high-water content fruits and veggies!
Although I have only provided you with two simple tricks, I did want you to know that there are several other studies that delve into ways to temporarily boost your metabolism. These include consumption of spicy food, drinking caffeine and ramping up the intensity during cardio sessions. I will keep it short today, and hopefully you are leaving this article with further knowledge about your metabolism and why it is decreases as we age. So we can stop playing the blame game and move forward with a strategy to improve it.
Coach CatÊ
