Building muscle is a common reason people work out. However, achieving this goal takes time and consistency. Muscle growth—called hypertrophy—occurs on a microscopic level every time you strength train, but it can take weeks or months to build muscle. In addition to exercise, muscle building is affected by other factors such as diet, training methods, hormones, and sex.
This article discusses how long it takes to build muscle, the factors that influence it, and recommendations for training to build muscle.
Can Fat Turn Into Muscle?
Fat does not turn into muscle since the two tissues comprise different types of cells. Fat cells store energy (calories) and provide energy during exercise, while muscle cells use (burn) more energy throughout the day. As a result, fat loss and muscle building often occur simultaneously.
How Fast Can You Gain Muscle?
Muscle building takes weeks or months to produce noticeable results. The amount of time it takes to build muscle is the same, regardless of the body part. For example, if you regularly train all muscle groups, your arm muscles don’t grow faster than your leg muscles, or vice versa.
Your training routine, the amount of weight you lift, your diet, and how much rest you get in between sessions impact how fast you gain muscle.
Muscle building is a physiological process that involves more than just lifting heavy objects. Working out has the following effects:
- Your heart pumps more blood (including oxygen and nutrients) to your muscles.
- Your nervous system is activated and sends signals to your muscles to tell them to contract.
- Your muscles break down adenosine triphosphate (ATP) for energy as you lift. They also use stored energy in the form of glycogen.
- When the glycogen is gone, and the muscle cannot produce any more ATP, it’s time to rest.
- As the muscles work, microtears develop within the proteins of muscle fibers (myofilaments).
- As you rest, your body builds bigger muscles by adding amino acids to the myofilaments, increasing their size.
Target the main muscle groups in each body area to build muscle efficiently.
Muscle Building: Women vs. Men
Men build muscle more quickly than women. There are a couple of reasons for these differences:
- Men tend to be taller than women and have longer bones, providing more leverage when lifting weights.
- Men have higher levels of testosterone (15 times higher than women after puberty), leading to greater muscle mass.
Target the biceps, triceps, and deltoids, as follows, to build muscle in the arms:
- Biceps: Your biceps are located at the front of your arm, between your shoulder and elbow. To strengthen your biceps, try hammer, preacher, or barbell curls.
- Triceps: Your triceps are located on the back of your arm, between your shoulder and elbow. Try triceps pushdowns, kickbacks, or close-grip bench presses to strengthen your triceps.
- Deltoids: Your deltoids are located on top of your shoulders. Try lateral raises, front raises, or overhead presses to strengthen your deltoids.
To build muscle in your legs, target your quadriceps, hamstrings, and glute muscles, as follows:
- Quadriceps: Your quadriceps are located on the front of your thighs. To strengthen your quadriceps, try leg presses, step-ups, or lunges.
- Hamstrings: Your hamstrings are located on the back of your thighs. To strengthen your hamstrings, try hamstring curls, squats, or dead lifts.
- Glutes: Your glutes are your buttock muscles. Try bridges, Romanian dead lifts, or Bulgarian split squats to strengthen your glutes.
The core muscles are located in the abdomen and lower back. Core strengthening exercises help build stability.
- Abdominal muscles: Your abdominal muscles provide stability to your trunk. To strengthen your abdominal muscles, try a plank, side plank, or crunches.
- Low-back muscles: Your low-back muscles help support your spine and keep your hips stable during movement. To strengthen your low-back muscles, try back extension over a stability ball, superman’s (lying on your stomach, lifting all four extremities simultaneously), or bridges.
How to Build Muscle
Many factors influence muscle growth, such as training methods, diet, hormones, and lifestyle behaviors.
Training for Muscle Growth
Weight lifting increases muscle growth. However, you need to lift a challenging amount of weight to experience muscle growth.
The American College of Sports Medicine recommends the following guidelines when lifting weight to build muscle:
- Target the main muscle groups with eight to 10 exercises, two to three times per week.
- Perform eight to 12 repetitions of each exercise, for two to three sets.
- Use a challenging weight. Rate your level of effort between zero (no effort) to 10 (maximum effort). Aim to use weights that require effort levels between eight and 10.
Another way to structure training is to base the amount you lift on the one repetition maximum—the heaviest weight you can lift once. Use weights between 70% and 85% of your one repetition max for muscle growth.
Eat More Protein
Muscles are primarily made up of proteins that are continually being “turned over”—broken down (degraded) and produced (synthesized). For muscles to grow, the amount of protein produced must be higher than the amount broken down.
Proteins are made up of amino acids. While the body makes many amino acids required for building muscle, there are other amino acids—called essential amino acids—that the body can’t make.
Essential amino acids come from high-protein foods such as:
- Beans, peas, and lentils (legumes)
- Dairy products
- Lean meats
- Nuts and seeds
- Soy products
The specific amount of protein needed to build muscle depends on many factors, including age, sex, and activity level. Online calculating tools can help you determine your minimum recommended daily protein intake based on these factors.
For specific recommendations, consult with a registered dietitian.
Get Enough Sleep
Getting enough sleep is essential for muscle growth. Although the amount of sleep required varies by individual, the general recommendation is between seven and eight hours per night. Too little or too much sleep can increase inflammation in the body, which can have a negative impact on muscle health.
Sleep quality also matters. To improve sleep quality at night, try these tips:
- Avoid caffeine in the evening.
- Do not take naps.
- Drink alcohol in moderation.
- Go to bed at the same time each night.
- Keep the room dark.
When to Train and Rest Muscles
When building muscle, it’s important not to overtrain. Muscle growth occurs while the muscle is healing after training sessions.
If your goal is to build muscle, do muscle-building exercises two to three times per week, with a day of rest between workouts for the muscle group targeted.
Reasons for Delayed Muscle Building
If you’ve been lifting weights consistently but aren’t seeing any results, there are a few possible explanations. Consider the following questions:
- Are you lifting heavy enough weights (i.e., weights that are 70% to 85% of your one repetition maximum)?
- Are you getting enough calories?
- Are you eating enough protein?
- Are you getting enough rest between workouts?
Hormones also play a role in muscle growth, especially as you age. To maximize your results, consider hiring a personal trainer or speaking with a healthcare provider about muscle-related concerns.
Building muscle takes consistency and patience. In general, muscle growth takes weeks to months to produce noticeable changes. Many factors influence muscle growth, such as training methods, diet, hormones, and quality of sleep. Ideally, muscle building workouts should be performed two to three times per week, with a day of rest between each workout.