Relying on cardio or aerobic activity to lose weight? You might find results take a very long time in coming. Typically only around 15-30% of the energy we use up during the day comes from exercise. The rest is down to our metabolism.
What is metabolism?
To maintain a pound of fat your body only needs to burn 2 calories a day. Muscle on the other hand requires 3 times as much energy!
Metabolism, or metabolic rate is the combination of biochemical processes that your body uses to convert food into energy and then use said energy to carry out your day to day activity as well as the functions that keep you alive – e.g.: breathing; pumping blood through your body to deliver nutrients & oxygen to all your cells; eating and digesting food; eliminating waste products from your body; maintaining your body temperature.
Each person’s metabolism is made up of 3 main aspects:
Basal Metabolic Rate + Thermogenesis + Physical Activity Levels
Basal Metabolic Rate (BMR) – the energy required to maintain your body’s normal functions while you are at rest. This will change depending on – your age, gender and weight. In addition, the more lean tissue (muscle) you have, the higher your BMR will be. A pound of fat only needs to use around 2 calories per day in energy; while muscle would typically use more like 6 calories a day (at rest).
Thermogenesis – Thermogenesis happens when your body undergoes any physiological process that generates heat. Activity such as digesting food and spontaneous physical activity usually contribute towards this. That said, Thermogenesis usually uses less than 5% of total energy usage.
Physical Activity Levels (PAL) – the more you move, the more energy you will burn. Movement can be part of day-to-day activity e.g. a nurse doing ward rounds, a brick layer laying bricks; or specific exercise activity e.g. walking, dancing, jogging, etc.
Key to maintaining weight is matching metabolism to food intake – so the higher your metabolism, the more you will be able to eat without gaining excess weight
Can I control my metabolism?
Short answer is Yes.
You can increase your metabolism by increasing your BMR and increasing your PAL (you have little control over Thermogenesis, and it is a small proportion of overall energy usage).
Increasing your BMR.
One of the most effective ways of increasing BMR is by increasing your muscle mass. As I mentioned earlier, muscle burns calories at rest so the more muscle you have the more calories you will burn even when you are not moving. You can increase muscle by taking part in activity that requires some weight bearing or resistance. Most movement types will fall into this category – e.g. walking, dancing, bowling, gardening, etc.
Other hacks for increasing BMR include:
Improved sleep – sleep deprivation causes the body to slow down the metabolism in order to conserve energy. Also, achieving enough restful sleep supports renewal of your muscles
Eat protein with each meal – eating food increases your metabolism while you digest the food. Eating protein raises the metabolism more than for carbohydrate or fats. Also eating protein usually has a more filling effect and so can prevent overeating.
Drinking cold water – your body needs to use energy to maintain your core temperature therefore your metabolism increases to cope with the cold water. If you drink water before your meals, you are likely to eat less
Increasing your PAL
Many of us have fairly sedentary lifestyles. We sit most of the time (when we are not sleeping!). Sitting or lying down uses much less energy than standing or moving around.
It is worth looking at your day to see where you can add more movement in order to increase your overall energy burn.
Stand up more – making a point of getting up regularly and moving around will increase the amount of energy you burn during the day
Change your commute – can you include more walking as part of your daily commute? Perhaps getting off the train or bus a little earlier? Or considering cycling? Or parking further away? If like many of us you are not commuting these days, how about a walk before work? This also has the advantage of improving your acuity / energy levels when you get back to your desk/kitchen table.
Choose a new hobby – consider finding an extra-curricular activity that involves moving your body. Anything from swimming, to skating, dancing, hiking / walking, gardening will increase the energy you burn overall. And can also do wonders for your mood.
The higher your metabolism, the more calories you burn. Having a higher metabolic rate can also give you more energy so you feel more alert and energetic.
Why you want Muscles
I already motioned that muscle, at rest, burns 3x as much energy as fat. However, did you also know that loss of muscle strength has been linked to declines in the immune system, not to mention weaker bones and stiffer joints? Muscle mass also plays an important part in our response to stress.
You might be a “healthy weight” however if that weight is predominantly fat, you will feel and look very different to a person that has more muscle in place of fat.
Fat stored in your abdominal cavity (i.e. in your belly), also called visceral fat; releases hormones that raise blood pressure, impact immunity, increase inflammation and mess with your blood sugars
Visceral fat reduces the release adiponectin hormone – this is the hormone that regulates metabolism. So, the more visceral fat you have the lower your metabolism – i.e. more fat begets even more fat!!
Fat takes up more volume than muscle therefore at the same weight someone with more fat will look bigger that a person with more muscle
Research has shown that after the age of 25, we all start to loose muscle – about a 5th of a pound per year from age 25 to 50 but then this accelerates to about a pound a year from age 50 onwards (this is one of the reasons it is so difficult to lose weight from age 50 onwards).
The solution is to actively seek to replace lost muscle using as many of the hacks above as you can manage – we each have just one body…