Optimize Your Nutrition. Elevate your Game

Nutrition plays a major role in an athlete’s performance, recovery, and long-term development. Whether you're training to compete or just working to improve your physical fitness, having a solid nutritional foundation is critical. This guide will give you a practical starting point to ensure you're fueling your body the right way.

Estimating Caloric Needs

Step 1: Calculate Your Basal Metabolic Rate (BMR)

To estimate your daily caloric needs, we begin with your BMR (Basal Metabolic Rate)—the number of calories your body burns at rest. A reliable method to estimate this is the Cunningham Equation:

BMR = 500 + (22 x Lean Body Mass [kg])

To determine lean body mass, you’ll need to know your body fat percentage. Methods include skinfold caliper testing or more accurate scans like the InBody scan.

Example:

  • Athlete weight: 75 kg (165 lbs)

  • Body fat: 15%

  • Body fat mass = 75 kg x 0.15 = 11.25 kg

  • Lean body mass = 75 kg - 11.25 kg = 63.75 kg

  • BMR = 500 + (22 x 63.75) = 1,902 calories

Step 2: Adjust for Activity Level

Next, factor in your daily activity using an Activity Factor (AF):

Activity LevelDescriptionAF ValueSedentaryLittle to no exercise1.2LightLight exercise/sports 1–3 days/week1.375ModerateModerate exercise/sports 3–5 days/week1.55HardIntense exercise 6–7 days/week1.725Very HardPhysical job or 2x training sessions/day1.9

Example:

  • Using a moderate activity level (1.55):
    TDEE = 1,902 x 1.55 = 2,948 calories/day

This number—TDEE (Total Daily Energy Expenditure)—is your baseline for maintaining your current weight. Adjust it to support your goals:

  • Surplus (weight/muscle gain): Eat more than 2,948 calories

  • Deficit (weight loss): Eat fewer than 2,948 calories

Breaking Down Your Macros

Now that you know your calorie needs, it’s time to allocate those calories to macronutrients: Protein, Carbohydrates, and Fats.

Protein: Building & Repairing Muscle

Protein is essential for muscle maintenance and growth. The NSCA recommends:

1.4–1.8 grams per kg of bodyweight

Example (75 kg athlete):

  • Target: 105–135g of protein per day

  • Calories from protein (1g = 4 cal):
    420–540 calories

Carbohydrates: Primary Energy Source

Carbs are critical for performance, especially in strength-based sports. The NSCA suggests:

5–6 grams per kg of bodyweight

Example:

  • Target: 375–450g of carbs

  • Calories from carbs (1g = 4 cal):
    1,500–1,800 calories

Fats: Hormonal Balance & Long-Term Energy

Once protein and carbs are calculated, the remaining calories go to fats.

Example:

  • High end: 540 cal (protein) + 1,800 cal (carbs) = 2,340 cal

  • Remaining calories: 2,948 - 2,340 = 608 cal

  • Fats (1g = 9 cal): 608 ÷ 9 = ~68g of fats

Final Nutritional Baseline

For our example athlete (165 lbs, 15% body fat, moderate activity):

  • Daily Calories: 2,948

  • Protein: 135g

  • Carbs: 400g

  • Fats: 68g

Conclusion

These estimates give you a reliable foundation to tailor your nutrition to your training goals. Everyone’s body is different, and your needs may shift based on your sport, training intensity, and physical goals.

If you're an athlete—or simply someone striving for better performance and health—I'm here to help you identify your starting point and build a plan for success.

Dedicated to your success,
Coach Eian

Eian Birtcher