What is a BMR?

BMR is an expression of a rate at which an individual is able to generate and retain energy during a full rest period. Almost all essential functions remain hidden – things like heartbeats, lung inhalation and exhaled air, filtration of waste by kidneys – creating new cells – maintaining proper body temperature, etc. BMR calculator calculates calories needed to sustain this essential bodily function. This amount amounts to about 60 – 70 % of an individual’s daily electricity usage.

How many calories are you burning in a day?

There are three main contributors to determine how many calories you burn in a day, these include Basal Metabolic Rate(BMR), Physical Activity, and the Thermic Effect of Food. (3) This sounds super ‘sciency’, let’s break it down for you.

The Thermic Effect of Food

The thermic effect of food is the energy (calories) it takes to digest what you eat, this accounts for 5-10% of your calorie burn for the day. Remember calories are just a measurement. We could call them anything but they would still just measure how much energy something contains.

Your body has to work hard to break down all those nutrients in food. After they are broken apart they need to get through your gut wall and end up in every tissue of your body. Are you tired of thinking about it? Well, your body isn’t, it does this every second of every day from before you were born until you die.

In order to use energy from food, you have to break it apart and this costs something. In this case, 5-10% of your overall calories.

This can be a hard concept to wrap your brain around but think about celery. Have you ever heard it is “negative” calories? Well, celery doesn’t pack a huge amount of calories it is providing, but it does cost your body effort to break the fiber apart and pull out the water and minerals. Since that is a significant effort, it is as if celery was a negative calorie food. Don’t get too stuck on this though, celery shouldn’t become your only food, just because eating it can net a calorie deficit!

Physical Activity

Physical activity was probably a given. Even if you aren’t running that marathon or hitting the gym, any movement is part of this category. Getting up to walk into the kitchen to grab an apple costs energy, and so does folding laundry, walking to your car, or the other extreme – something like weight lifting.

Physical activity makes up the second largest portion of your “calorie expenditure”. Yet, it seems to be the portion people focus the most on when it comes to weight loss. This portion makes up 15-30% of your energy expenditure for the day. 

Basal Metabolic Rate (BMR)

Last, but certainly not least, is your basal metabolic rate (BMR). Before I jump into the stats for BMR let’s discuss what the heck “basal” means. ‘Basal’ is simply the bottom layer or base of something. (4) In this case, it’s your base layer of energy needs.

Your BMR represents 60-75% of the energy needed for survival – so that’s the majority. Meaning, if you were to be bedridden, your BMR is the MINIMUM amount of calories needed for weight maintenance and survival. (5) 

Knowing that BMR makes up the greatest portion of your energy needs, it makes sense to target your BMR for weight loss goals. This is also an incredibly helpful thing to boost early in adulthood as your basal metabolic rate will decline as you age.

How can we increase your BMR?

Basal metabolic rate is determined largely in part by how much lean muscle mass you have. (6) Muscles require a lot of energy, therefore, the more muscle you have the greater calorie burn you will enjoy.

One great advantage in PCOS is higher levels of androgens. You didn’t expect to hear that, did you? Yep, androgens can actually help build lean muscle tissue which has many downstream benefits metabolically and hormonally. Androgens help you to increase your lean muscle tissue faster than others. In fact, doing exercises that will increase lean muscle mass will also have the benefit of using up that extra testosterone and decreasing levels. It’s like a two-for-one benefit!

To increase your lean muscle mass and boost your metabolism, you’ll need to incorporate muscle-building exercises into your physical activity. (7) This could be weight-bearing exercises like push-ups, squats, or lunges. If you prefer yoga or pilates, these are great options too. Just be sure you are challenging your muscles to hold your body weight- this will encourage that lean muscle mass to increase! Notice those are all things you can do at home without any equipment.

Won’t Weight Lifting Make My Muscles Too Big and Bulky?

Lifting weights will NOT make you look like the hulk, this is a horrible media myth. Trust me, any woman who has noticeable muscle or “bulk” has been working on their physique for YEARS, and good for them! You better believe their basal metabolic rate is also in beast mode!

While increasing your lean body mass can increase your metabolism by increasing your basal metabolic rate, many women with PCOS are resistant to this type of exercise due to concerns about bulking up.

There are some misconceptions here. To gain the physique of a fitness model and elaborate muscle definition requires a level of weight lifting and exercise that we are not talking about here.

Focusing on weight-bearing exercise a few times per week can help increase lean body mass and decrease adipose tissue (fat mass). This doesn’t mean only focusing on strength training or completely avoiding aerobic exercise. The other component to bulking up to the level of muscle many are resistant to is protein intake. Most of us can not consume in a normal diet the amount of protein it would require to build bulky muscle or maintain it.

The other part of this narrative that it is important we discuss is the idea of “strength”. Having a strong body can help you accomplish daily tasks with less effort and for a longer period as you age. For many years the idea of being thin and frail was a cultural idea. There is a very healthy change that is currently happening where we are focusing on strength instead of thinness. So while you may not bulk up like strong bodybuilders by adding in strength training, I encourage you to think of gaining strength as a very positive pursuit.

How Can I Increase My BMR The Most Efficiently?

Your main focus during your workout should be the large muscle groups. Think of muscles from your shoulders to your knees, front and backside. This includes the abdominals, chest, back, glutes, quads, and hamstrings. These muscles are the largest and require the most energy (calories). That doesn’t mean you shouldn’t add in some bicep curls or calf raises- simply make the majority of your routine focused on those bigger muscles. 

When you’re ready you can start adding weights such as dumbbells, barbells, resistance bands, and anything else you might have access to. Remember that building muscle takes time and consistency, don’t get discouraged if you don’t see results overnight.

Experts are worth the investment. You wouldn’t go ride a sailboat for the first time without someone that knew how to sail. Working with fitness experts can help you get the most out of the time you are putting into sweat and help you avoid injury. When and where possible, consider hiring a trained professional to help guide you in your fitness journey.

Increasing Your BMR Is Not Just About Exercise – Food Matters Too

It’s also important to remember how to fuel our bodies for this type of goal. Your body will not be able to increase muscle mass if you are eating inadequate amounts of protein or inadequate amounts of calories. You can’t make matter out of nothing and you need protein to build muscle.

One of the worst mistakes people make to lose weight is they exercise without eating enough. Your body has a primary objective to keep you alive. This is more important than gaining muscle or helping reproduce. If resources are limited, your body will not signal muscle tissue building or cycle regularity. While you need to consume enough protein to build muscle you also can not enter too large of a calorie deficit and expect redistribution to come in the form of muscle and lean tissue.

Please don’t confuse the loss of fat as “fat turning into muscle”, this is another marketing fib, fat cannot convert to muscle and muscle cannot magically turn into fat; they are separate components of your body composition.  Another great outcome of adding resistance training to your workouts, other than increasing lean muscle mass and BMR, is you will likely lose body fat. Wahoo! 

The real magic here is that by building muscle through resistance training you are increasing your basal metabolic rate AND burning more calories with your workout routine. Essentially you burn more calories during exercise and at rest.

Remember, you are also burning through and using some of that testosterone. It’s a win-win-win. So, be patient, be consistent and keep moving forward. You got this! 

Body Composition Changes Impact Insulin and Androgen Levels

As your body composition changes and adipose tissue decreases your levels of insulin, leptin, testosterone and estrogen can all decrease. This is really powerful for symptoms of PCOS including weight gain, cycle irregularity, hair loss, excess hair growth, acne, and more.

Adipose tissue is not very metabolically active, meaning it doesn’t take a lot of calories to keep it around. Yet, adipose or fat tissue is very hormonally active. It can create hormones like estrogen and testosterone. It can also impact the creation of leptin. Leptin is the “I’m full” hormone. It tells your brain to stop eating. As adipose tissue levels increase, so does leptin, and leptin resistance can follow.

As lean muscle mass increases it is normal to see average blood sugar levels decrease. While lean muscle does weigh more than adipose tissue, it is more dense and can actually help with losing weight in the long term.

Improving blood sugar levels and lowering insulin levels can decrease overall insulin resistance which is incredibly helpful for resolving symptoms of polycystic ovary syndrome (PCOS) including menstrual cycle health and fertility.