The 4 truths about building muscle

Building muscle : What you need to know

Exercise is good for your health! But people don’t exercise just for their health. Many do it to change how they look. That often means trying to build more muscle.

Chasing bigger muscles can sometimes lead to poor health. Some people work out too much or use bad technique and get hurt.

Others use risky substances like steroids, hoping for quick results. This can harm both physical and mental health. Research shows that people who are focused on getting muscular often feel unhappy with their bodies. This can lead to problems like low self-esteem, depression, eating disorders, and anxiety.

To avoid these risks, it's important to set realistic goals and rely on trustworthy information. Sadly, there is a lot of bad advice out there — especially online. Many websites claim to have the secret to fast muscle growth, but often they just want to sell a product or program. Here are four science-based facts about building muscle.

Truth #1: Respect Your Genetics

How much muscle you can gain depends in part on your genes. Building muscle also takes time. Instead of focusing on making your biceps a certain size or hitting a specific fat-free mass or body fat percentage, focus on healthy habits—like proper training, eating well, and getting enough rest. If you do these things over time, your body will naturally change and your muscles will grow to their full potential.

Truth #2: You Need to Challenge Your Muscles

Muscles grow when you challenge them. When you push, pull, or lift against resistance, your muscles have to work harder than usual. This mechanical tension signals your body to grow your muscles. 

The best way to challenge your muscles is by resistance training. Resistance training means doing exercises that work your muscles against some form of resistance. The resistance can come from lifting weights, using your body as a weight, pulling resistance bands, or pushing and pulling machines like gym equipment.

There are other factors that help. For example, exercise damages the muscle a little, so the body can then repair it stronger. Similarly, the chemicals that build up in the muscles when exercising (the ones that give you the “burn”) signal the muscles to adapt and grow.

Aim to work all major muscle groups —  chest, back, arms, legs, shoulders, and core — 2 to 3 times each week. To learn more, talk to a certified trainer or visit trusted sites like participaction.com or Mayo Clinic Fitness (put those words into a search engine).

Truth #3: Muscles Grow When You Rest 

Muscles grow and get repaired during rest time, especially during sleep. When you are sleeping, your body releases hormones, enzymes, and other chemicals that signal your body to repair and build your muscles. When you don’t get enough sleep, your body can't repair and build your muscles in the same way as when you are well-rested. In fact, processes that contribute to the breakdown of muscle, like inflammation, are ramped up when you are missing sleep.

Most people need 7–9 h of quality sleep to support their muscle-building goals.

Muscles also need time to recover and grow after being challenged. If you work the same muscle two days in a row, they won’t grow as much as they can if you had included rest in between trainings. The guidelines from reliable resources like the American College of Sports Medicine recommend that you take 48 to 72 hours between resistance training workouts that challenge the same muscle group. 

Truth #4: Muscles Need the Right Fuel

To grow, muscles need energy and nutrients. You must eat enough calories; a little more than when you are not working on building muscles. It is best to eat a variety of foods from all food groups so that your body and muscles get all the nutrients it needs, including protein, carbohydrates, fats, as well as vitamins, minerals, and other micronutrients.

To get enough nutrition, it can be helpful to eat a balanced meal or snack several times throughout the day. It is hard to get all the nutrition your body and muscles need if you are only eating 1 or 2 times a day.

Many people think they need a LOT of protein to build muscle. While yes, you do need protein, you need all the nutrients. Some sources present the recommendations as percentages of your total calories; others as a number of grams per kg you weigh. You can find these online and use them as a guide when you plan your meals. 

Another simple approach is the ratios approach suggested by Canada’s Food Guide, that suggests you aim to include food from each food group in each meal and snack you eat.

Some people add more protein in their diet in the form of powders or bars. There is no harm from getting some of your protein in powder form occasionally. But when you get your nutrients, including protein, in the form of whole foods, you get much more variety of nutrients. The way the body absorbs whole foods also seems to benefit the muscle-building more than when the nutrient comes in powder form.

About Supplements and Steroids 

Many supplements promise fast muscle-building results. However, when we look at what benefits are supported by research, we see that the claims made by the companies that make and sell these products are often exaggerated.

Steroids are a different story. These powerful drugs act like testosterone and can increase muscles. They are sometimes used in medicine under supervision but are also used illegally by bodybuilders.

Steroids can seriously harm your health. They can damage your heart, cause acne, liver problems, heart disease, mood swings, infertility, and even death. In men, they can lead to shrinking testicles and breast growth. The risks are high — and not worth it.

What about other factors?

There are many interesting areas of research concerning growing big muscles, including protein timing, length of rest between sets, promising supplements, and a lot more. However, we don’t yet have strong enough evidence to make clear recommendations.

Further, even when a practice is found to be statistically significant in a research article, it does not mean it will make a practical, noticeable difference in a recreational athlete’s day-to-day life and muscles. For example, recent systematic reviews and meta-analyses on the effect of creatine supplements found that when used along with resistance training, it increased lean body mass in young men by around 1 kg. For some people, this difference may not be meaningful or worth the effort of paying for and adding a supplement daily.

Instead, for now, we encourage you to focus your resources of time, energy and, mental bandwidth on the above 4 sound and well-supported recommendations we listed above. Once you are doing all these things consistently for a long time, you can think about connecting with a specialist, such as a coach, personal trainer, or registered dietitian, to tweak your efforts.