Learn About Your Basal Metabolic Rate (BMR) For Weight Loss Or Muscle Gains

Understanding your Basal Metabolic Rate (BMR) is crucial whether your goal is to lose weight, gain muscle, or maintain your current physique. BMR is the number of calories your body needs to function while at rest—essentially, the amount of energy your body requires to maintain vital functions like breathing, circulation, and cell production without any additional physical activity. Knowing your BMR can help tailor your diet and exercise plan to meet your specific goals, whether you're aiming for fat loss or muscle gains. In this article, we'll explore what BMR is, how it relates to weight management, and how to calculate it to optimise your fitness journey.

What Is basal metabolic rate (BMR)?

Basal Metabolic Rate (BMR) refers to the minimum number of calories your body needs to sustain life while at rest. It accounts for about 60-70% of your daily caloric expenditure and includes essential functions like maintaining your heart rate, body temperature, and brain activity.

While your BMR reflects your energy requirements at rest, it doesn't account for physical activity or the energy burned during digestion (thermic effect of food). Adding these factors will give you your Total Daily Energy Expenditure (TDEE), which is the total number of calories you need in a day, depending on your activity level.

How BMR affects weight loss

For those aiming to lose weight, understanding your BMR is essential because it helps determine your caloric deficit—the number of calories you need to consume below your BMR to lose fat. Since weight loss occurs when you burn more calories than you consume, knowing your BMR gives you a baseline for how many calories your body needs to maintain your weight without any additional activity.

To lose weight:

Step 1: Calculate your BMR.

Step 2: Multiply your BMR by your activity level to find your TDEE (Total Daily Energy Expenditure).

Step 3: To lose weight, aim for a caloric intake of about 500 calories less than your TDEE. This moderate deficit typically results in a weight loss of about 1 pound per week.

For example, if your TDEE is 2,500 calories, consuming 2,000 calories per day would create a deficit that promotes gradual weight loss.

How BMR affects muscle gains

If your goal is to gain muscle, knowing your BMR is equally important. To build muscle, you need to consume more calories than your body expends, creating a caloric surplus. Without an adequate calorie intake, muscle gains will be limited, regardless of how hard you train.

To gain muscle:

Step 1: Calculate your BMR.

Step 2: Multiply your BMR by your activity level to find your TDEE.

Step 3: For muscle gain, aim to consume 250–500 calories above your TDEE. This surplus provides your body with the extra energy it needs to repair and grow muscle tissue after resistance training.

For example, if your TDEE is 2,500 calories, eating 2,750 to 3,000 calories per day can help support muscle growth.

How to calculate BMR

There are several ways to calculate your BMR, with the Harris-Benedict Equation being one of the most popular methods. The formula takes into account your weight, height, age, and gender.

a. For Men:

BMR= 88.362+(13.397×weight in kg)+(4.799×height in cm)−(5.677×age in years)

Example: BMR=88.362+(13.397×weight in kg)+(4.799×height in cm)−(5.677×age in years)

b. For Women:

BMR= 447.593+(9.247×weight in kg)+(3.098×height in cm)−(4.330×age in years)

Example: BMR=447.593+(9.247×weight in kg)+(3.098×height in cm)−(4.330×age in years)

Once you've calculated your BMR, you can estimate your TDEE based on your activity level:

Sedentary (little or no exercise): BMR × 1.2

Lightly active (light exercise 1-3 days/week): BMR × 1.375

Moderately active (moderate exercise 3-5 days/week): BMR × 1.55

Very active (hard exercise 6-7 days/week): BMR × 1.725

Super active (very hard exercise or a physical job): BMR × 1.9

This calculation will give you a good estimate of how many calories you need to maintain your weight. From there, you can adjust your intake based on your specific fitness goals—either by creating a deficit for weight loss or a surplus for muscle gain.

Factors that influence BMR

Several factors can influence your BMR, including:

1. BMR tends to decrease as you age, due to a reduction in muscle mass and other metabolic changes.

2. Men generally have a higher BMR than women, mainly due to having a higher percentage of muscle mass.

3. Muscle mass burns more calories than fat, even at rest. Therefore, people with a higher muscle-to-fat ratio have a higher BMR.

4. Genetic factors can affect how efficiently your body burns calories.

5. Thyroid hormones play a crucial role in regulating metabolism, and any imbalances can significantly impact BMR.

6. Your body uses more energy to maintain its temperature in extreme cold or hot environments, which can temporarily increase your BMR.

Tips for using BMR to achieve your goals

1. Track your caloric intake

Once you know your BMR and TDEE, use a calorie-tracking app to monitor your daily caloric intake. This will help ensure you're either in a caloric deficit for weight loss or a surplus for muscle gain.

2. Incorporate strength training

Strength training helps build muscle mass, which can increase your BMR over time. The more muscle you have, the more calories you burn, even while resting.

3. Prioritise protein

Protein is essential for both weight loss and muscle gain. It helps preserve lean muscle mass during a caloric deficit and provides the building blocks for muscle growth during a surplus.

4. Adjust your diet as needed

Your caloric needs will change as you progress toward your goals. Recalculate your BMR every few months or when you notice a plateau in your weight loss or muscle gain.

Understanding your Basal Metabolic Rate (BMR) is a key step in achieving your fitness goals, whether they involve weight loss or muscle gain. By calculating your BMR and adjusting your caloric intake based on your activity level, you can create a personalised plan that maximises results. Remember that while BMR provides a useful foundation, it's essential to combine this knowledge with proper nutrition, regular exercise, and rest to achieve lasting success.

Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.