What are Macronutrients and Why Do They Matter in Fitness?

At Foundry it’s pretty clear we take our fitness very seriously.

But I would be lying if I said that was the biggest part of finding your most confident self. No matter where you are at, if you are still consuming 1500 calories worth of alcohol per week, rarely getting 7 hours of sleep, and not managing your stress and recovery…you are going to find it extremely difficult to hit your goals and stay there. If you want to be good at ANYTHING, you have to be consistent. If you are learning a new skill, you must work it consistently. If you are studying for an exam, you must study consistently. If you are looking to improve a relationship, you mut put in the effort consistently.

When it comes to fitness goals such as gaining muscle, losing weight, enhancing athletic performance, or achieving mass gain, macro calculations are a pivotal part of the equation. Macronutrients—proteins, carbohydrates, and fats—are the building blocks of our diet and play a crucial role in shaping our body composition and overall health. By understanding and calculating your macronutrient needs accurately, you can tailor your nutrition to meet specific fitness objectives. This article delves into the significance of macro calculations and explores different macro prescriptions for various fitness goals.

Understanding Macronutrients

Macronutrients, often referred to as “macros,” are nutrients required by the body in large amounts to maintain energy and support bodily functions.

The three main macronutrients are:

Proteins: Essential for muscle repair and growth, proteins are made up of amino acids. They play a vital role in building muscle and aiding recovery after exercise (reducing soreness/fatigue so you can get back after it the next day). I always suggest clients aim for 20-50g of protein post workout, and 25-35g per meal which should get you over 100g per day for women and 150g per day for men.

Carbohydrates: The primary source of energy for the body, especially during high-intensity activities. Carbohydrates are broken down into glucose, which fuels our muscles and brain. The best time to get your carbohydrates in is right after you train. Carbs aren’t the devil but they definitely serve a purpose (when you’re most active) so when you’re less active, you need less carbs. When you’re more active (if you’re on this thread, you’re probably pretty active) then you need more but timing is pretty key and I NEVER eat carbs without getting my protein in first (because it is the hardest to get).

Fats: Important for hormone production, nutrient absorption, and providing long-lasting energy. Fats are also crucial for overall health and well-being. I’m sorry for anyone who was tainted by the 90’s and still think fats are bad. I tend to avoid high amounts of fat within 2 hours before and after my workouts but each meal definitely contains healthy fats. A great way to feel better in your skin is to limit cheap fats and oils (if you’re someone who eats out for half their meals during the week, and all 3 meals on Saturday are at restaurants……….)

The Role of Macro Calculations

Macro calculations involve determining the right balance of proteins, carbohydrates, and fats needed to achieve specific fitness goals. This process is highly individualized and depends on factors such as age, gender, weight, height, activity level, and metabolic rate. By using a macro calculator, individuals can get personalized macro prescriptions that align with their objectives. I always say that we need a map whenever we visit a new city, so learning about your food intake is very similar.

Macro Prescriptions for Different Goals

Lean Muscle Gain

For those looking to gain lean muscle, the focus should be on a higher protein intake to support muscle synthesis. Carbohydrates are also important to provide the energy required for intense workouts.

A typical macro prescription for muscle gain might look like:

Proteins: 30-35% of total daily calories

Carbohydrates: 45-50% of total daily calories

Fats: 25-30% of total daily calories

According to a study published in the Journal of the International Society of Sports Nutrition, consuming 1.6 to 2.2 grams of protein per kilogram of body weight per day is effective for muscle gain. This means that if I weigh 145 pounds (68kg) and am looking to build muscle, I need around 108-150g of protein per day.

Weight Loss

For weight loss, creating a calorie deficit is essential, but the macronutrient distribution should still support muscle maintenance and energy levels. A higher protein intake helps preserve muscle mass while losing fat.

A common macro prescription for weight loss might be:

Proteins: 25-30% of total daily calories

Carbohydrates: 40-45% of total daily calories

Fats: 25-30% of total daily calories

Research in the American Journal of Clinical Nutrition suggests that high-protein diets are more effective for weight loss and maintaining muscle mass compared to lower-protein diets.  In essence, you still want to hit minimum 108g of protein per day, while monitoring your carb and fat intake.

Athletic Performance

Athletes require a balanced intake of all macronutrients to support their training demands and recovery. Carbohydrates are particularly crucial for providing quick energy (remember when we found out Michael Phelps consumed 12,000 calories a day while training for the Olympics?).

A typical macro prescription for athletic performance might include:

Proteins: 20-25% of total daily calories

Carbohydrates: 50-60% of total daily calories

Fats: 20-25% of total daily calories

The International Society of Sports Nutrition recommends that athletes consume 5-7 grams of carbohydrates per kilogram of body weight per day to optimize performance and recovery .

Mass Gain

Mass gain or bulking requires a caloric surplus, with an emphasis on both protein and carbohydrates to fuel growth and support muscle synthesis.

A common macro prescription for mass gain might be:

Proteins: 25-30% of total daily calories

Carbohydrates: 50-55% of total daily calories

Fats: 20-25% of total daily calories

A study in the Journal of the American Dietetic Association found that consuming adequate carbohydrates in addition to proteins is crucial for muscle hypertrophy and overall mass gain.

Using Macro Calculators

Macro calculators are invaluable tools for determining your personalized macronutrient needs. These calculators take into account your specific details such as age, weight, height, gender, and activity level to provide a tailored macro prescription. Websites like IIFYM (If It Fits Your Macros) and apps like MyFitnessPal offer user-friendly macro calculators that can help you stay on track with your nutrition goals. If you are looking to go in-depth, I like TDEECalculator.net. If you are looking to lose weight, select “Sedentary” under the Activity Level tab to get a baseline. Whenever you implement something new, I suggest trying it consistently for two weeks before making any changes.

Macro calculations are a fundamental aspect of achieving any fitness goal, be it gaining muscle, losing weight, enhancing athletic performance, or mass gain. It can also be an intimidating and challenging process for a large segment of the population. 

Macro calculations are just one piece of the puzzle and what most weight loss / body transformation programs focus on.


If you need personalized help with your nutrition, email me at KSmith@Foundry13Detroit.com and let’s have a discussion.