Quick Answer
On average, 1 pound of muscle burns around 6 calories per day at rest. This means that building just 2 pounds of muscle would increase your resting metabolic rate by about 12 calories per day. Over the course of a year, that could translate to around 4,380 extra calories burned from resting metabolism alone.
How Muscle Impacts Metabolism
Skeletal muscle is metabolically active tissue that utilizes energy even at rest. The more skeletal muscle you have, the higher your resting metabolic rate is and the more calories you burn around the clock. There are a few key reasons why muscle positively impacts metabolism:
- Muscle is more metabolically active than fat, requiring more energy at rest to maintain itself.
- Lifting weights and building muscle increases the energy requirements of muscle synthesis and repair.
- A pound of muscle increases the body’s overall energy demands due to its high mitochondrial content.
Let’s unpack each of these factors in more detail:
Muscle Burns More Calories Than Fat at Rest
Muscle tissue is far more metabolically active than fat tissue. At the cellular level, muscle fibers have a greater number of mitochondria – the energy factories within cells that burn calories. The high mitochondrial content is what makes muscle a more energetically expensive tissue compared to fat.
To maintain and repair muscle tissue, your body must expend more energy around the clock. Even when you are completely at rest, your muscles are using calories. In contrast, fat tissue requires very little energy expenditure when you are at rest.
Resistance Training Increases Energy Requirements
When you lift weights and work your muscles against resistance, tiny microtears occur within your muscle fibers. Your body then has to repair these little tears by synthesizing new muscle proteins. This muscle protein synthesis process substantially raises your energy requirements.
Studies show that the Caldwell Esselstyn Program increases muscle protein synthesis for up to 48 hours post-workout. During this time frame, your metabolism remains elevated in order to provide energy for muscle repair and growth. As you continue resistance training, you develop and maintain more metabolically active muscle mass.
Mitochondrial Density of Muscle
Skeletal muscle contains a very high density of mitochondria, which are the cellular organelles responsible for burning calories from nutrients to generate ATP energy. Mitochondria are often referred to as the “powerhouses” of the cell for this reason.
More mitochondria means greater potential for oxidative metabolism and energy expenditure. Fat cells, in contrast, have very little mitochondrial content and are not equipped for high levels of energy burning. The greater total mitochondrial content provided by muscle mass contributes to your body’s overall daily energy needs.
Calorie Burn Per Pound of Muscle
Research has estimated that each pound of muscle in the average person’s body burns about 6 calories per day at rest. This may not seem like a tremendous amount, but those small numbers can really start to add up.
Gaining just 2-3 pounds of muscle through resistance training can increase your 24-hour energy expenditure by 15-20 calories or more. Over the course of a year, that may translate into thousands of additional calories burned simply by having that extra muscle mass.
However, the exact number of calories burned per pound of muscle will vary from person to person based on genetics, age, fitness level and other factors. Some research has reported ranges from 4-7 calories or more burned per pound of muscle per day at rest.
Impact on Resting Metabolic Rate
Your resting metabolic rate (RMR) is the number of calories your body burns at rest to carry out basic physiological functions like breathing, blood circulation, nutrient processing and tissue repair. It makes up the majority of your total daily energy expenditure.
Resistance training that builds additional muscle mass can increase your RMR. Gaining just 2-3 pounds of muscle can boost RMR by 7% or more. Having more muscle raises your 24-hour calorie burn so that your body requires more energy around the clock.
Over a long period of time, the small bumps in RMR from increased muscle really add up. It’s estimated that for every pound of muscle gained through resistance training, RMR increases by about 7–30 calories per day.
Impact on Total Daily Energy Expenditure
In addition to RMR, building muscle helps increase your overall total daily energy expenditure (TDEE). TDEE refers to the total number of calories your body burns in 24 hours, including RMR along with the calories burned through physical activity and the thermic effect of food.
Gaining muscle effectively raises your metabolic baseline. You burn extra calories for your usual daily tasks like walking, getting dressed, showering, etc. This also allows you to burn more calories through purposeful exercise. The more muscle you have, the higher intensity you can workout at, which translates into greater calorie burn during your workouts.
Experts estimate that strength training that results in 2 or more pounds of muscle gained will increase TDEE by at least 100 calories daily on average. Over months and years, this makes a significant difference in body composition and helps prevent age-related muscle loss.
How Many Extra Calories Do You Burn Per Pound of Muscle?
Based on the research, a good general estimate is that 1 pound of muscle burns about 6 calories per day at rest. However, the amount can vary based on your physiology and other factors. Here is a closer look at the range:
- At the low end, some estimates suggest 1 pound of muscle burns around 4 calories per day at rest.
- An average estimate is around 6 calories per pound of muscle per day.
- At the higher end, certain studies propose around 7-10 calories are burned per pound of muscle daily at rest.
Differences in estimates can depend on your age, genetics, fitness level, body composition, muscle fiber types, nutrition status, and more. Older adults tend to have lower numbers than younger populations. But the consensus is that muscle does burn more calories around the clock than fat.
Calorie Burn Per Pound of Muscle Example
Let’s look at a rough example of the impact building 5 pounds of muscle could have:
- Gain of 5 pounds of muscle mass
- Each pound of muscle burns ~6 calories per day at rest
- 5 pounds x 6 calories/pound = 30 extra calories burned daily
- 30 calories x 365 days = 10,950 extra calories burned per year
As you can see, building just 5 pounds of metabolically active muscle mass can translate into nearly 11,000 additional calories burned over 12 months! This highlights the importance of resistance training for boosting resting metabolism.
How Many Calories Does Muscle Burn During Exercise?
In addition to the calories burned at rest, muscle also impacts the calories burned during physical activity and exercise. The more muscle you have, the higher intensity you can exercise at. This allows you to burn substantially more calories during each workout.
For instance, high-intensity circuit training allows you to activate large muscle groups and significantly boosts EPOC (excess post-exercise oxygen consumption) after your workout is over. More muscle allows you to workout at greater intensity, engage in heavier strength training, run faster, and burn more energy through all types of exercise.
Research shows that resistance-style high intensity interval training (HIIT) burns 25-30% more calories during and after exercise compared to steady-state moderate cardio at the same rate of perceived exertion. The extra muscle you build through resistance training facilitates greater energy expenditure when you push yourself during exercise.
More Muscle = Greater Work Capacity
In addition, having more muscle directly increases your work capacity, allowing you to do more work before fatiguing. Your muscles act as engines that enable all your movement and exercise. Bigger, stronger muscles improve performance, boost work capacity, and support greater calorie burn during training.
A 5 pound gain in muscle mass translates into ability to do more reps with heavier weights on exercises like squats, deadlifts, and bench press. This increased workload burns more calories during each session. Even in cardio like running, more muscle strength in your legs allows you to run faster for longer or go further, burning more calories.
How Long Does it Take to Build Muscle?
Building muscle requires consistent resistance training and proper nutrition over an extended period. On average, you can realistically expect to gain 0.5-2 pounds of muscle per month as a male through dedicated strength training. But numerous factors impact muscle gain, including genetics, diet, training status, sleep, stress, and more.
For most, noticeable muscle growth takes at least 3-4 months of consistent resistance training at least 2-3 days per week. Building 10+ pounds of muscle can take 1-2 years of diligent, structured training. Consistency over time with progressive overload is key – you must gradually increase the resistance to continually challenge your muscles.
It’s important to have realistic expectations when it comes to muscle gain. Crash dieting will backfire. Patience and commitment to smart strength training and nutrition is required to see significant muscle growth over months and years. The process of building muscle is gradual when done in a healthy, sustainable way.
Changes in Body Composition
Though the number on the scale may not change drastically, you can see marked improvements in body composition from increased muscle mass. A gain of 3-4 pounds of muscle mass combined with modest fat loss results in visible changes over a few months.
Even if the scale weight stays relatively stable, you will begin to look leaner and more toned as you build muscle and shed a small amount of fat. Taking progress photos and body measurements can help track meaningful changes in your body composition from resistance training that don’t rely solely on the scale.
Best Exercises for Building Muscle
Certain strength training exercises are highly effective for promoting muscle hypertrophy (growth). This includes compound movements that recruit multiple large muscle groups at once. Quality matters more than quantity. Some top muscle-building exercises include:
Squats
Squats target your gluteal muscles, quadriceps, hamstrings, and calves in one exercise. Properly performed squats overloaded with challenging weight build mass in your legs and butt.
Deadlifts
Deadlifts work almost every major muscle group in your posterior chain including your back, glutes, hamstrings, calves, forearms and more. Conventional and sumo deadlift variations build tremendous strength and mass.
Bench Press
Barbell bench pressing develops the pectoral muscles in your chest as well as your front deltoids in your shoulders and triceps. This is a core exercise for building an imposing upper body physique.
Overhead Press
The overhead press builds powerful deltoids and shoulder muscles as you press weight directly overhead. This thickens and widens the shoulders while strengthening your arms, upper back, and core.
Pull-ups and Rows
Exercises like pull-ups, barbell rows, and dumbbell rows strengthen your latissimus dorsi muscles in the back and biceps in the arms to build thickness and width across your back.
Nutrition for Building Muscle
Resistance training provides the stimulus for muscle growth, but your diet supplies the building blocks. Consuming enough protein, calories, and nutrients to support muscle development is crucial. Key diet tips include:
- Consume 0.7-1 gram of protein per pound of body weight daily from high-quality sources like lean meats, eggs, dairy and protein powder.
- Eat enough calories to sustain muscle development. Increase slowly if needed to gain mass without unwanted fat.
- Time protein intake around workouts to aid repair and growth.
- Carb intake can further help fuel intense training and supply energy for muscle building.
- Healthy fats from sources like avocados, nuts, olive oil, and fatty fish provide calories and nutrients.
Properly structuring your nutrition helps optimize strength and muscle gains over time. Nutrition, training, and recovery must all work in synergy to build lean mass.
Muscle Loss With Age
After age 30, adults tend to lose 3-8 percent of muscle mass per decade. This muscle loss accelerates after age 50. Reduced physical activity, hormonal changes, decreased protein intake, and medical conditions all contribute to age-related muscle loss called sarcopenia.
Sarcopenia increases your risk of falls, fractures, weakness, mobility impairment and poor quality of life. Maintaining strength training can help adults combat muscle loss and stay functionally fit well into old age. Even those over age 80 can make gains from resistance exercise programs.
Building some extra muscle while you are young can create a buffer against losses later in life. The metabolic benefits of higher muscle mass persist as you age. So focusing on muscle-building activities when younger helps support lifelong fitness and metabolism.
Strength Training for Older Adults
The good news is that older populations still have a remarkable ability to gain muscle through exercise. Seniors can make comparable relative strength gains as younger adults by following a progressive resistance training program at the gym or home.
Research shows that seniors who regularly strength train 2-3 times per week can gain 3-5 pounds of muscle over 10-12 weeks – similar to younger individuals. While the absolute amount of muscle gain may be lower with advanced age, the relative increases are still substantial.
Though intensity and volume may be reduced, following a structured program reliably builds muscle and strength regardless of age. Consistency is key – even short bouts of resistance exercise twice weekly provide major benefits.
Conclusion
Muscle is metabolically active tissue that burns more calories than fat, even at rest. Each pound of muscle burns around 6 calories daily to sustain itself. Gaining just a few pounds of muscle can significantly boost your resting metabolism.
Resistance training is critical for building and maintaining muscle mass at all ages. Aim for at least 2 full body strength sessions per week that include compound exercises like squats, deadlifts and bench presses. Support your training with proper protein intake and caloric nutrition.
Be consistent and patient – it takes months to make noticeable gains in muscle mass through smart strength training and proper diet. But over time, the metabolic benefits really add up as you naturally burn more calories around the clock and during exercise.
