Resting Metabolic Rate

Resting Metabolic Rate is the number of calories your body burns through the course of a day, even if you were to do absolutely nothing.  RMR is an important tool to be aware of, especially if you are working to lose or maintain your weight.  In the June issue of the IDEA Fitness Journal there was an article with some extensive information about RMR, we would like to provide you with some of the deatils. 

The impact of diet-only weight loss efforts on RMR.
It has been found that restricting your diet and not exercising at all can reduce your RMR by up to 20%.  This means that if your RMR is 1500 calories burned per day could drop by 300 calories.  That's bad news if you are serious about losing weight.  Following a diet-only program tends to result in decreased muscle mass which reduces your RMR and hurts your weight loss effort.

Long term aerobic exercise impact on RMR.
A study in 2008 was conducted over 16 months and had participants do aerobic exercise 3 to 5 days per week at moderate intensity for 20-45 minutes per session.  Females in the study saw an average RMR increase of 129 calories burned per day, and males saw an average increase of 174 calories per day.  If you achieved this increase you would see your calories burned per week go up by 903 for women and 1218 for men, and that is not including what you would burn from actually doing the exercise! That is tremendous!

Long term resistance exercise impact on RMR.
In a 26 week study particpants were put through regular resistance exercise routines that included doing 2 sets of 10 reps for each major muscle group at 65-80% of their maximum capability.  By the end of the study the particpants had seen an RMR increase of 7%, or about 100 calories per day.  That translates to a weekly calorie burn of 700 calories and that is not including the calories burned while actually doing the resistance exercise!

How do you estimate RMR?
There are many different estimation techniques out there.  The following is Mifflin-St. Jeor RMR Equation:
Males RMR = 10 x (weight in kilograms) + 6.25 x (height in cm) - 5 x (age in years) + 5

Females RMR = 10 x (weight in kilograms) + 6.25 x (height in cm) - 5 x (age in years) -161

Body weight in KG = weight in pounds divided by 2.205
Height in CM = height in inches x 2.54