Sports & Gaming · Dietetics
Post Workout Nutrition Calculator
Calculates optimal post-workout protein, carbohydrate, and calorie intake based on body weight, workout intensity, and goal.
Calculator
Formula
Protein and carbohydrate targets are derived by multiplying body weight (kg) by intensity- and goal-adjusted factors. Each gram of protein and carbohydrate provides 4 kcal.
Source: American College of Sports Medicine (ACSM) Position Stand on Nutrition & Athletic Performance, 2016; International Society of Sports Nutrition (ISSN) Post-Exercise Protein Guidelines.
How it works
The calculator uses evidence-based multipliers for body weight (kg) that vary by workout intensity and goal. Protein factors range from 0.20 g/kg for low-intensity sessions up to 0.40 g/kg for very high-intensity sessions combined with a muscle-gain goal. Carbohydrate factors range from 0.20 g/kg for low-intensity fat-loss sessions up to 1.40 g/kg for very high-intensity endurance goals, reflecting the greater need to restore muscle glycogen after prolonged work.
Total post-workout calories are computed as (Protein g + Carbs g) × 4 kcal/g, since neither macronutrient contains fat. The anabolic window estimate is simply half the total protein target, representing the ideal dose to consume within the first 30 minutes post-exercise — a practical split when a full meal is not immediately available.
These values represent the post-workout meal or snack only, not total daily intake. Always integrate them into your overall daily macronutrient plan.
Worked example
Example: A 80 kg athlete finishes a 75-minute heavy resistance session (High intensity) with a goal of Muscle Gain.
- Protein factor: 0.30 (high) + 0.05 (muscle gain) = 0.35 g/kg → 80 × 0.35 = 28 g protein
- Carb factor: 0.80 (high) + 0.10 (muscle gain) = 0.90 g/kg → 80 × 0.90 = 72 g carbohydrates
- Calories: (28 + 72) × 4 = 400 kcal
- Anabolic window protein: 28 ÷ 2 = 14 g within 30 minutes
A practical meal could be 200 g Greek yoghurt (18 g protein) + a large banana (27 g carbs) + 60 g oats (40 g carbs, 5 g protein) to meet these targets.
Limitations & notes
These recommendations are population-level estimates and do not account for individual metabolic rate, gut tolerance, or specific sport periodisation. Athletes following carbohydrate periodisation or ketogenic protocols will need to adjust carbohydrate targets accordingly. Heavier athletes (>120 kg) may hit absolute protein ceilings (typically 40 g per meal for maximal muscle protein synthesis) even when body-weight multipliers suggest more. Always consult a registered sports dietitian for personalised plans.
Frequently asked questions
What is the anabolic window and how long does it last?
The anabolic window refers to the period after exercise when muscles are particularly receptive to nutrients for repair and growth. Research suggests the window is most critical within 30–60 minutes post-exercise, though total daily protein intake matters more than precise timing for most recreational athletes.
Why are carbohydrates important after a workout?
Exercise depletes muscle glycogen (stored carbohydrate). Consuming carbohydrates post-workout stimulates insulin release, which shuttles glucose into muscle cells for glycogen re-synthesis and also aids amino acid uptake, enhancing the muscle-building stimulus from protein.
Should I eat fat in my post-workout meal?
Fat is not included in this calculator because it slows gastric emptying, potentially delaying amino acid and glucose delivery to muscles. However, a small amount of healthy fat (e.g., from whole foods) is generally fine and does not meaningfully impair recovery in most contexts.
How does the fat-loss goal affect the recommendations?
For fat loss, the calculator increases protein slightly (to preserve lean mass in a calorie deficit) and reduces carbohydrates slightly (to lower total caloric intake). The overall post-workout meal is still designed to support recovery, just with a more conservative carbohydrate load.
What protein sources are best after a workout?
Fast-digesting, leucine-rich proteins are preferred immediately post-workout: whey protein isolate/concentrate, Greek yoghurt, eggs, or lean chicken. Plant-based athletes can combine pea and rice protein, or soy protein, to achieve a complete amino acid profile comparable to whey.
Can I use this calculator for endurance sports like running or cycling?
Yes. Select 'Endurance Performance' as your goal and the appropriate intensity level. Endurance athletes require notably higher carbohydrate replenishment — the calculator reflects this with elevated carbohydrate multipliers, especially at high and very-high intensities.
Last updated: 2025-01-30 · Formula verified against primary sources.