In simple terms, our metabolism is the rate at which our bodies utilize calories. The higher our metabolic rate, the faster our bodies expend calories.
Our metabolism may be influenced by a number of variables including our age, gender and genes – factors which may seem completely out of our control. The good news is that there are certain things we can do to help maximize our body’s calorie burning potential and improve our global health.
The strategies I set out in this feature are science-based. To be sure, I know of no magic pill, pouch or bullet that will do for you what exercise and sound dietary choices can.
recipe for my gingered pear green smoothie here
- Men generally have a higher metabolic rate than women – this is because they have a higher percentage of muscle mass and muscle burns more calories than fat, even at rest.
- Metabolism generally decreases with age – this is often attributed to loss of muscle mass, which is certainly a key consideration, but the situation is more complex than that. Hormonal changes that occur in women during the perimenopausal and postmenopausal phases of their lives, can also contribute to metabolic changes and increased fat storage (study).
- Our Daily Energy Expenditure – our daily energy expenditure is made up of three main components: (i) our resting metabolism or basal metabolic rate (BMR) – the energy required to perform our vital body functions while at rest (breathing and heart beating for example) – BMR can make up as much as 75% of our daily calorie expenditure; (ii) our physical activity – anywhere from 15-30% of our daily expenditure depending on our activity level; and (iii) thermogenesis – the energy needed to digest and absorb food – somewhere around 10% of daily expenditure depending on the type of food consumed.
- Start where you are, do what you can — it’s important when considering the strategies below to always work within your individual parameters, whatever they may be — age, stage of life, health considerations, fitness levels.
1. Build Muscle
Muscle is our body’s most efficient calorie burner. The more muscle mass we have, the higher our metabolic rate and the more efficiently our body is going to use calories, even at rest.
The very unique (and wonderful) thing about building muscle mass is that it not only requires us to expend energy during the exercise of weight training (the ‘physical activity’ prong) it also, critically, raises our resting metabolic rate because muscle is more metabolically active than fat — so we end up burning more calories simply lying on the couch than we would if we had less muscle mass. That’s a pretty nice return on our investment.
Building muscle mass not only helps improve our body’s calorie burning potential, it also helps build the necessary foundation to keep us strong and robust as we age. Weight-bearing and/or resistance exercises are integral to maintaining strong and healthy bones. Women are especially vulnerable to loss of bone mass in the years following menopause as estrogen production drops significantly.
Strength training most commonly comprises of weight lifting and/or resistance exercise. Weight lifting — customarily through the use of weight machines or free weights such as dumbbells and barbells. Although a gym environment may offer the most efficient way to use this equipment, you certainly don’t have to go this route. You can invest in dumbbells of differing weights and use them in the privacy of your own home. If you are new to weights, start with lighter weights and gradually/safely build over time. Strength training that offers resistance by way of equipment — such as rubber bands and balls — or by using the body’s own weight to create resistance — notably: push-ups, planks and dips as well as squats and lunges used in tandem with bands/balls — can also be very helpful and offers a broader range of options. Exercise classes that incorporate these weight-bearing and/or resistance exercises such as Pilates, yoga and interdisciplinary aerobics/interval training, provide multiple benefits and are also well worth investigating.
2. Engage in Aerobic Exercise
Any aerobic activity from walking, dancing, cycling, rowing, swimming to running (and many more) will increase calorie expenditure. The longer and more intense the workout, the more calories expended. Aerobic exercise also has the advantage of benefiting our cardiovascular system, bone health, circulatory system and mood.
◊ The best type of aerobic exercise is the kind that you enjoy and that you’re more likely to do on a regular basis. This is what building a sustainable lifestyle is all about ~
Keep in mind too that exercise is cumulative. If you only have 10 minutes at lunch — use it and try and sneak in another 10 minutes after dinner. Any amount of exercise is worthwhile and beneficial so don’t feel like the circumstances have to be ideal before partaking. The trick is to start — do what you can, when you can. As a general rule, aim to include at least 30 minutes of aerobic activity into your daily routine. You can challenge yourself by adding time and intensity to your workouts over time and experiment with different types of exercise to see what works best for you.
3. Consider High Intensity Interval Training (or HIIT)
HIIT is a training technique that involves alternating intervals of high-intensity exercise followed by brief recovery periods. HIIT can be a very demanding/intense form of training and it is not for everyone. HIIT is lauded for its ability to not only burn calories during the course of the exercise itself but also notably, for its ability to burn calories following the completion of exercise (this is due to an increase in excess post-exercise oxygen consumption — or EPOC — wherein the body continues to recover from the intense exercise ~ sucking wind as my friend would say).
Although studies have shown that interval training does raise EPOC and calorie expenditure following exercise (study), it would appear that this increase is highest among untrained individuals (study). The higher your cardiorespiratory fitness level, the lower the magnitude of EPOC you will experience. Stated differently, the better shape you are in, the less you will benefit from the post-exercise calorie burn because you recover more quickly and your body’s metabolism returns to normal sooner. In well-trained individuals the post-exercise caloric expenditure, or after-burn, has been found to be as low as 1% (with a mean of 4.8%) (study). Still, an average 4.8% post-exercise expenditure is more than baseline and if you enjoy HIIT (and it’s a safe form of exercise for you), you can certainly take advantage of the metabolic benefits.
4. Eat a balanced diet that includes sufficient Protein
I’ve written about the importance of protein in other features (and will no doubt do so again). Unlike carbohydrates that are metabolized relatively quickly into sugar in the body, protein requires more work for our bodies to break down and metabolize. This not only leads to a higher expenditure of energy relative to other macronutrients that we consume, it also means that protein can help stabilize our blood-sugar levels, improve our sense of fullness and satisfaction and assist in helping our mood and concentration.
Keep in mind as well that protein is essential for building muscle mass (strategy number 1 above).
There is also new and compelling research to suggest that individuals who consume normal- and high- range protein in their diets store more excess calories as lean tissue, or muscle mass, than those on low-protein diets – and while the mechanism is not yet fully understood, this remains a promising area of study (research).
5. Make sure you’re getting enough Sleep
Sleep is intimately connected to hormonal processes in the body and critical for maintaining metabolic homeostasis. Sleep deprivation has been associated with multiple physiological changes, including increased cortisol and ghrelin levels, decreased leptin levels, impaired glucose metabolism, increased pro-inflammatory markers (review, review) and decreased energy expenditure.
A compelling study published in the American Journal of Clinical Nutrition showed that just one night of total sleep deprivation was enough to significantly reduce resting metabolic rate in adult men in comparison to those obtaining 8 hours of sleep. Since up to 75% of the calories we consume during the day are used by our bodies while at rest, this is a significant finding.
Most adults require 7 to 8 hours of restorative sleep per night. More information on sleep and strategies for obtaining a better one, here.
The information in this post is provided for educational purposes only and is not intended as a substitute for the advice of your physician. Always consult your physician or other health care professional directly before beginning or changing a course of health treatment.