How Much Does Strength Training Boost RMR?
I found out some interesting information in my dive down the rabbit hold investigating Resting Metabolic Heart Rate. Take a rather lengthy, but worthwhile read, to see what I found out.
Resting Metabolic Rate is "the energy required by your body to perform the most basic functions when your body is at rest" (verywellfit). These functions include things like breathing and circulation. You may have also encountered the term, Basal Metabolic Rate, which is relatively the same thing. Verywellfit.com says, "Although BMR is slightly more accurate, the difference is only notable in clinical settings."
This article will refer to Resting Metabolic Rate (RMR). You can calculate your RMR with one of this trusted calculator or if you want to calculate it yourself, here you go ( for my mathematicians).
Harris-Benedict Equation for BMR:
Men: BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) - (5.677 x age in years)
Women: BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) - (4.330 x age in years)
The average for women is 1,400 and for men it's 1,600 (Verywellfit.com).
Here is an interesting look at the breakdown of what effects RMR from UNM EDU. (TDEE refers to total energy expenditure).
Muscle tissue contributes approximately 20% to TDEE versus 5% for fat tissue (for individuals with about 20% body fat). It is fascinating to note that the combined energy expenditure of the heart, lungs, kidneys, brain and liver represent approximately 80% of the TDEE (Elia 1992).
So why is RMR important? It is part of your body's daily total caloric expenditure (how many calories you burn in a day). The other significant modes of expenditure involve movement (getting up and down, walking to the kitchen, putting food in your mouth, AND exercise). So while you may only burn 1400 calories based on your RMR, you are typically burning around 300 more calories with daily movements, and if you're exercising then you're burning even more!
Another fun fact about the relationship between exercise and RMR is that strength training can actually increase your RMR. That's right, adding muscle to your body, will increase the amount of calories your body burns at REST....while you're doing NOTHING! You heard me right.
So while cardio is excellent at burning calories in the moment, strength training has the lasting effect of burning calories for you around the clock. Wonderful right?!
Ok, but how much does weight training really help to burn extra calories? Unfortunately, despite common rhetoric in the fitness world, research shows that it doesn't make a significant difference in your RMR. If you'd like to read a science-based article explaining the research go here. The conclusion found is that strength training makes a minimal impact on increasing RMR, but is very useful at retaining muscle when someone is attempting to lose weight.
This was new information to me, and I hope you found it useful. So, we may just be adding some more cardio to our workouts, huh? The combination of both cardio and strength training is important, and there are many benefits to strength training aside from RMR.