How to Determine Your Macronutrients: A Guide for Athletes

An athlete's diet is crucial for achieving a long and successful career. Proper nutrition provides the fuel to train hard, the nutrients to adapt and recover, and the support needed to stay healthy and injury-free. Determining the right amount of energy and macronutrients (protein, carbohydrate, and fat) is a personalized and constantly evolving process. This guide will walk you through the foundational steps to estimate your needs.

The calculations and recommendations below are estimates and should be used cautiously. A "food first" policy is the best approach to sports nutrition, and for a personalized plan, it is critical to consult with a qualified professional like a sports dietitian or sport scientist.

Energy intake (EI) is the starting point for any sports nutrition plan. It determines your capacity to consume the macronutrients and micronutrients needed to fuel your training and optimize your body composition.

Your daily calorie needs are known as the Estimated Energy Requirement (EER). The EER is the sum of your resting metabolic rate, the energy used for digesting food, and the energy you expend during physical activity.

You can estimate your EER using the following equations from the sources:

• For Males >19 years: EER = 662 − (9.53 × age) + {PA coefficient × [(15.91 × weight in kg) + (539.6 × height in m)]}
• For Females >19 years: EER = 354 − (6.91 × age) + {PA coefficient × [(9.36 × weight in kg) + (726 × height in m)]}

To use these formulas, you first need to determine your Physical Activity Coefficient from the list below, based on your Physical Activity Level (PAL).

• Physical Activity Level: Sedentary - Performs common activities of daily living (ADLs). (Physical Activity Coefficient Male/Female:1.00/1.00) 
• Physical Activity Level: Low Active - ADLs + 30-60 min of daily moderate activity. (Physical Activity Coefficient Male/Female:1.11/1.12) 
• Physical Activity Level: Active - ADLs + 60 or more min of daily moderate activity. (Physical Activity Coefficient Male/Female:1.25/1.27) 
• Physical Activity Level: Very Active - ADLs + 60 or more min of moderate activity + an additional hour of vigorous activity or 2 hours of moderate activity. (Physical Activity Coefficient Male/Female:1.48/1.45) 

Protein is critical for athletes as it augments strength gains, aids in muscle maintenance during weight loss, and enhances satiety. The protein intake recommended for sedentary individuals (0.8 g/kg/day) is too low for athletes.

• For Maintaining or Gaining Weight: Athletes should aim for 1.3 to 1.7 grams of protein per kilogram of body mass per day (g/kg/day).

• For Losing Weight (while maintaining muscle): Higher protein intakes of up to 2.4 g/kg/day are recommended.

For recovery, consuming a snack or meal with ~20-25 grams of high-quality protein soon after an exercise session can maximize muscle protein synthesis for repair and adaptation. This optimal protein serving should be part of a pattern of eating every 3-5 hours to keep protein synthesis optimized.

Carbohydrate intake for athletes should be personalized and periodized, meaning it should change daily based on the fuel costs and goals of each training session rather than following a static high-carbohydrate diet.

The following guidelines are for when high carbohydrate availability is desired to support high-quality or high-intensity training and competition.

Daily Needs for Fueling and Recovery:

• Light Training Load (Low-intensity or skill-based activities): 3-5 g/kg/day
• Moderate Training Load (~1 hour/day of moderate exercise): 5-7 g/kg/day
• High Training Load (1-3 hours/day of moderate- to high-intensity exercise): 6-10 g/kg/day
• Very High Training Load (>4-5 hours/day of moderate- to high-intensity exercise): 8-12 g/kg/day

Acute Fueling Strategies for Competition:

• Carbohydrate Loading: For events lasting >90 minutes, consume 10-12 g/kg/day for 36-48 hours beforehand.
• Pre-Event Fueling: Consume 1-4 g/kg between 1-4 hours before exercise lasting >60 minutes.
• During Endurance Exercise (1-2.5 hours): Aim for 30-60 g/hour to supplement the body's own stores. This is also recommended during high-intensity exercise lasting around 1 hour.
• During Ultra-Endurance Exercise (>2.5-3 hours): Aim for up to 90 g/hour, using products with multiple transportable carbohydrates (e.g., glucose:fructose mixtures).

You can calculate fat intake after calculating your needs for protein and carbohydrates. Fat will make up the remainder of your total daily calories.

To calculate this, you need to know the caloric value of each macronutrient. 

• Protein: 4 calories per gram
• Carbohydrates: 4 calories per gram
• Fat: 9 calories per gram

Calculation:

1. Protein Calories: Your Protein (g) × 4
2. Carbohydrate Calories: Your Carbohydrate (g) × 4
3. Fat Calories: Your Total EER − (Protein Calories + Carbohydrate Calories)
4. Fat Grams: Fat Calories / 9

Managing athlete nutrition is a complex task that requires expertise. These calculations provide a solid starting point, but they cannot replace a personalized assessment from a qualified professional. Dietary apps are popular but should not be a substitute for professional consultation. A professional can help you:

• Fine-tune these estimates to your specific goals and training cycle.
• Assess for potential issues like Low Energy Availability or micronutrient deficiencies.
• Develop practical and sustainable eating strategies that fit your lifestyle.
• Ensure you are meeting your goals safely and effectively.

You now have the tools to estimate your energy and macronutrient needs. To put this knowledge into action, here are three, actionable ways to move forward:

1. Map Out Your Macronutrients
   Use the formulas and guidelines in this article to calculate your calorie, protein, carbohydrate, and fat targets. Start experimenting with adjustments based on your training demands and see how your body responds.
2. Book a Consultation
   If you want expert guidance tailored to your sport, body, and goals, schedule a consultation with me. Together, we’ll fine-tune your nutrition plan and make sure you’re fueling for peak performance and long-term health.
3. Explore Trusted Supplements
   While food should always come first, high-quality supplements can support your nutrition strategy. I recommend Transparent Labs for clean, effective products that complement an athlete’s fueling plan. Click the link to get 10% off your purchase.