If you are concerned about fitness, you may be familiar with BMR and BMI. As for those of you that are not sure what these terms mean, read further.

What is BMI?

BMI is known as your Body Mass Index and is an indirect measure of your body composition. It determines your body fat using a formula compromising of your height and weight. The resultant number can determine is you are normal weight, underweight, overweight or obese.

BMI = (weight/height²) 

The weight in kilograms and height in metres.

  • A BMI of 18.5 to 24.9 is classified as normal weight.
  • A BMI of 18.4 or below is classified as underweight.
  • A BMI of 25 to 29.9 is classified as overweight.
  • A BMI of 30 or above is classified as obese.

What is BMR?

BMR, on the other hand, is known as your Basal Metabolic Rate. It measures the number of calories your body burns while at rest, doing basic functions. These functions can range from keeping your heart beating, digesting, breathing and other physiological tasks. Your BMI and day-to-day activity levels have an effect on your BMR. To calculate your BMR you would need to use the Harris Benedict Equation. BMR calculation can vary due to several reasons:

  • Gender – BMR can be different for men and women.
  • Age – BMR declines as you get older
  • Reduced food intake – metabolism slows down if you don’t consume the required amount of calories per day. Reduced food consumption can cause your body to think it is in starvation therefore, result in lower metabolism rate.
  • Regular exercise regimen – can increase your BMR, however, make sure you are consuming as much calories for your exercise regime. Generally athletes consume very high amounts of calories per day.

Generally, BMI and BMR calculations are according to American standards. However, genetics play a major role in these measures. For instance, in Japan if someone has a BMI of over 25 they are considered obese. Therefore, it is essential to note that your fitness levels are not determined by BMI and BMR standards. For instance, athletes tend to have high BMIs due to their increased muscle mass. It is best to seek a professional for help with your fitness queries.

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