What Is RMR And Why Should You Care?
Resting Metabolic Rate (RMR) is the number of calories your body burns at rest just to keep you alive, think breathing, circulation, and basic brain function. For most men, RMR accounts for 60–75% of total daily calorie expenditure (Müller et al., Obesity Reviews, 2022).
Why is that important? Because whether you’re trying to lose weight, build muscle, or improve endurance, your RMR sets the baseline for how your body uses energy. And yet most people have no idea what theirs is.
Why RMR Matters for Men Ages 30–70
As men age, RMR naturally declines due to:
- Loss of muscle mass
- Decreased physical activity
- Hormonal changes, including testosterone reduction
According to thec, men over 50 can experience a 10–20% drop in RMR compared to their 30s, even if their weight stays the same. That means fewer calories burned at rest and more stored as fat with the exact same diet.
By understanding your RMR, you can:
- Accurately calculate your caloric needs
- Avoid crash dieting or under eating
- Train more efficiently
Tailor your macros (protein, carbs, fats) for real results
RMR and Training: It’s More Than Just Calories
If you’re lifting weights or doing HIIT, RMR plays a critical role in post exercise recovery and muscle growth. Higher lean mass = higher RMR.
A study published in Medicine & Science in Sports & Exercise (2020) showed that resistance training can increase RMR by 7–8% over 12 weeks, especially when combined with adequate protein intake (1.6–2.2g/kg of body weight).
Men who trained with progressive overload and consumed enough calories reported fewer plateaus and better body composition than those who used generic diet plans.
How to Measure Your RMR
There are three main options:
- Clinical Indirect Calorimetry (Gold Standard)
Use oxygen consumption to give you a precise calorie burn number. MMFT offers this type of testing.
- Smart Wearables & Apps
Devices like WHOOP, Fitbit, or Apple Watch offer RMR estimates, but can vary widely in accuracy. In fact, errors of 20% to 30% are not uncommon when using wearables.
- RMR Calculators (Mifflin-St Jeor Formula)
An estimate using age, weight, height, and sex. It doesn’t take into consideration your body composition and the uniqueness of your body and therefore can be highly inaccurate.
Quick RMR Facts for Men
- Muscle burns ~6 kcal/lb per day, while fat burns only ~2 kcal/lb
- Low RMR = slower fat loss, even on a calorie deficit
- Sleep deprivation and stress lower RMR (Spiegel et al., The Lancet, 2004)
- Protein rich diets can boost RMR via the thermic effect of food
So, What Should You Do?
Understanding your RMR is like knowing your financial budget; it tells you how much energy you must “spend” daily. If you’re dieting without it, you’re flying blind.
At Maze Health, we work with people every day who:
- Can’t lose weight despite eating “clean”
- Gain fat during muscle building phases
- Struggle with low energy or metabolism in midlife
RMR testing and strategic coaching help cut through the noise. You deserve data driven results, not guesswork.
