Skeletal muscle is one of the three main types of muscle in our body. These muscles are connected to bones by tendons, and when they contract, they help us move.
In this article, we’ll explore how to strengthen skeletal muscles. We’ll cover the best exercises to do, what foods to eat, and when it’s important to rest and stretch.
How does muscle grow in the body?
Muscles grow bigger when you keep pushing them to handle more resistance or heavier weights. This process is called muscle hypertrophy.
Muscle hypertrophy happens when muscle fibers get damaged or injured. The body repairs these fibers by fusing them together, which makes the muscles bigger and stronger.
Certain hormones like testosterone, human growth hormone, and insulin-like growth factor also help with muscle growth and repair. These hormones help by:
- Improving how the body uses protein
- Reducing protein breakdown
- Activating satellite cells (a type of stem cell that helps muscles grow)
- Boosting anabolic hormones, which support muscle growth and protein building
- Encouraging tissue growth
Strength and resistance training can help your body:
- Release growth hormone from the pituitary gland
- Stimulate testosterone production
- Make muscles more sensitive to testosterone
Do males and females grow muscle differently?
How fast someone can build muscle depends on several things, like genetics and the levels of estrogen and testosterone in their body.
No matter your sex, muscle growth happens at different speeds based on your body type. Both men and women can have one of these body types, and each one requires a unique approach to building muscle:
- Mesomorphic: People with this body type are naturally more muscular and usually build muscle faster than others.
- Ectomorphic: This body type is slim or straight. Ectomorphs may find it harder to gain muscle mass but can still increase strength with resistance training.
- Endomorphic: Endomorphs have a rounder or curvier shape. They can build muscle effectively through strength training.
Sports scientist Dr. Tony Boutagy, in an interview with ABC, mentioned that men tend to grow muscle faster due to traits like larger muscle mass, higher testosterone levels, and tighter joints.
Building muscle through exercise
People build muscle at different speeds depending on their age, sex, and genetics. However, muscle growth happens faster when exercise is:
- Consistent
- Challenging
- Long-term
Rest is also crucial for seeing the best results after exercise.
The best way to build muscle is through strength training, although cardio can also be beneficial.
Strength Training
It can take several weeks or even months of consistent effort before you start noticing muscle growth. According to the Physical Activity Guidelines for Americans (2015–2020), adults should do muscle-strengthening exercises that target all major muscle groups at least twice a week.
Some examples of strength training activities include:
- Lifting free weights
- Using stationary weight machines
- Resistance band workouts
- Bodyweight exercises like pushups and squats
- Strength training classes that combine some or all of these activities
A 2019 review found that doing three sets of resistance exercises was generally more effective than just one set, though even a single set can still offer benefits.
Strength Training for Aging Adults
As we age, we face a higher risk of mobility issues and conditions like osteoporosis and osteoarthritis. Older adults should try to follow adult exercise guidelines if possible, or stay as active as their bodies allow. Strength training is especially important for preventing injuries and helping with recovery.
Cardiovascular Activity
Cardio, also known as aerobic exercise, benefits your heart and lungs. It’s essential for overall health. The current guidelines recommend at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity cardio each week.
While some think cardio doesn’t help build muscle, recent studies suggest otherwise. Regular cardio supports muscle growth, improves fitness, and lowers the risk of injury.
For optimal muscle building, research suggests:
- Doing cardio at 70–80% of your heart rate reserve (calculated by subtracting your resting heart rate from your maximum heart rate)
- Exercising for 30–45 minutes per session
- Working out 4–5 days a week
Rest and muscle growth
Rest is a key part of building muscle. If you don’t give your muscles time to recover, they can’t repair properly, which slows down your progress and raises the risk of injury.
According to the MOVE! program from the U.S. Department of Veterans Affairs, you shouldn’t train the same muscle group two days in a row.
Getting enough sleep is also important for muscle growth. A 2011 study suggests that lack of sleep may slow down protein synthesis, lead to muscle loss, and prevent proper muscle recovery. However, more research is needed to confirm this.
While a 2019 study didn’t find a direct link between sleep and muscle gain, the authors noted that sleep deprivation can raise cortisol levels after exercise. Cortisol is a stress hormone, and high stress can negatively impact muscle growth.
Reducing stress may help with muscle development since the hormones released during stress can interfere with building muscle.
Diet and building muscle
Eating a balanced, healthy diet is essential for staying fit, and protein is especially important if you’re trying to build muscle.
The recommended daily protein intake is 56 grams for men and 46 grams for women.
Timing your protein intake can also make a difference. A 2013 paper from the Nestlé Nutrition Institute Workshop Series suggests that eating 20 grams of protein during or right after exercise helps boost muscle growth, reduce muscle breakdown, and improve recovery.
Good sources of protein include:
- Meat
- Fish
- Eggs
- Milk and cheese
- Soybeans and tofu
- Beans and lentils
- Nuts
- Seeds
Tips for beginners
A fitness professional can help you learn the correct form for lifting weights and using gym equipment. Using proper technique not only reduces the risk of injury but also helps you build muscle more effectively.
Here are some useful tips to keep in mind:
- Warm up and stretch for 5–10 minutes before doing strength or cardio exercises.
- Start with light weights and gradually increase the weight or resistance over time.
- Always use proper form, breathe correctly, and keep your movements controlled.
- Expect some soreness and muscle fatigue, especially in the beginning. But if you feel too much pain or exhaustion, your workouts might be too intense, too long, or too frequent.
If you have any health issues or concerns about injury, it’s a good idea to check with a doctor before starting a new exercise routine. Otherwise, a personal trainer or gym staff member can offer safety advice.