Why Does Your Trainer Keep Talking About Protein?
- Connor Gannon
- Jul 31
- 4 min read
What Is Protein?
Protein is one of the three main nutrients, or macromolecules, your body needs to function, along with carbohydrates and fats.
Proteins are made up of a smaller unit called amino acids. Your body uses amino acids to build and repair tissues, make enzymes and hormones, and support your immune system. Certain amino acids can be made by your body, but others called essential amino acids must be obtained through consuming different foods and drinks. Foods like meat, eggs, fish, dairy, soy, and quinoa are called complete proteins because they contain all the essential amino acids your body is unable to produce. Many plant-based proteins, like beans or rice, are missing some, but you can mix and match them to get everything your body needs.

What Is Protein Synthesis?
Protein synthesis is the process your body uses to build new proteins from the amino acids you eat. Think of it as a repair and growth system. This process becomes extra important when you exercise, especially if you participate in resistance training. After a workout, your muscles get small tears. Protein synthesis helps repair those tears which results in strength and potentially size increases. Eating protein post-workout gives your body the nutrients it needs to build new muscle. A special amino acid called leucine plays a key role in turning this process on.
How Protein Helps Build Muscle?
When you work out, especially when you lift weights, your muscle fibers accumulate a bit of damage.This triggers protein synthesis to help repair muscles which is how you increase you abilities in the gym. But to do that, your body needs enough protein. If you do not eat enough protein, your muscles will not have the materials they need to properly and efficiently perform protein synthesis to aid in the reparation process. That is why people who want to build muscle or maintain it as they age are often told to eat more protein, especially after workouts. Studies have shown that people who combine strength training with higher protein intake build more muscle and get stronger over time. This is especially true for older adults who naturally lose muscle as they age. Eating more protein and staying active can slow that muscle loss and improve strength and balance.
How Much Protein Do You Need?
The general recommendation for adults who do not exercise much is about 0.8 grams of protein per kilogram of body weight each day. That is around 56 grams for an average man and 46 grams for an average woman. However, this is the bare minimum to avoid health problems, it is not necessarily ideal. If you are active, especially if you lift weights, play sports, or are trying to lose fat while maintaining muscle, you certainly need more.
The most current research suggests Adults who are active need to consume 1.2 to 2.0 grams of protein per kilogram of body weight each day. For example, a 150-pound person might need around 80 to 130 grams of protein per day depending on their activity level. Older adults may need even more, closer to 1.5 grams per kilogram, because their bodies do not use protein as efficiently. Spreading your protein out across the day with meals that each contain 25 to 30 grams is a smart way to help your body build and maintain muscle.Â
These are general guidelines, some people especially those who participate in heavy weightlifting or high intensity sports may require even more protein per day.
Protein Supplements
Sometimes it is hard to get enough protein from food alone. That is where protein supplements (ready to drink shakes, powders, etc.) come in. These supplements are sometimes the easiest and most convenient way to get your protein each day. They require very little prep time and can often be taken with you anywhere. The benefits of protein powder are:
Support muscle growth and recovery after exercise
Fill in nutritional gaps if you are not getting enough protein from meals
Make it easier to reach higher protein targets during busy days
Protein powder, while convenient may not be the best way to hit your protein goal each day. There is some research that shows the absorption of protein power is much lower than that of real food protein sources (Meat, eggs, milk, etc) so trying to get your protein from whole foods is more recommended and will likely yield more benefits. But supplements can still be useful tools, especially for athletes, busy professionals, or older adults.
Different Types of Protein Powders
There are many types of protein powders out there. The most common are made from milk, but there are also plant-based options. Here are the main types:
Whey Protein
Whey comes from milk and is quickly digested. It is rich in essential amino acids and great for taking right after workouts. It is one of the most popular and effective protein powders for building muscle.
Whey Concentrate has a bit more fat and lactose but still has lots of protein
Whey Isolate has most of the fat and lactose removed and is very high in protein
Whey Hydrolysate is broken down more, which may help it absorb faster and be easier to digest
Casein Protein
Casein is the other main protein in milk. It digests slowly, which makes it a good choice before bed or during long stretches without food. It feeds your muscles over several hours and may help reduce muscle breakdown.
Plant-Based ProteinsÂ
Soy, pea, rice, and hemp proteins are good options for vegetarians or people who are lactose intolerant. They usually digest a bit slower than whey and might not have as much of the key amino acid leucine, but many blends are made to match the benefits of dairy-based proteins.