Protein

Definition

Proteins are macromolecules made of amino acids, considered the "building blocks" of the body. They make up every tissue: muscles, skin, organs, hormones, enzymes, antibodies.

For lifters, protein is the most critical macronutrient: without enough intake, building or preserving muscle mass is impossible.

💡 1 gram of protein delivers 4 kcal. Of the 20 existing amino acids, 9 are "essential": your body cannot synthesize them — they must come from food.

Why protein is essential

Beyond muscle, proteins fulfill dozens of vital roles:

• Muscle building: fiber synthesis after training
• Tissue repair: skin, ligaments, cartilage
• Hormone production: insulin, glucagon, growth hormone
• Immune system: antibodies, natural defenses
• High thermic effect: 20-30% of calories burned just to digest
• Satiating effect: better satiety than carbs or fats

How much protein per day?

Example: an 80 kg lifter bulking aims for 130 to 175 g of protein per day.

⚠️ Beyond 2.5 g/kg/day, studies show no additional benefit on muscle gain.

Best protein sources

Animal sources (more complete)

• Lean meats: chicken (31 g/100g), turkey, lean beef
• Fish: tuna (25 g/100g), salmon (20 g/100g)
• Eggs: 6 g/egg, ideal amino acid profile
• Dairy: skyr, cottage cheese, Greek yogurt

Plant sources (combine for complete profile)

• Legumes: lentils, chickpeas, beans
• Soy: tofu, tempeh, edamame
• Grains: quinoa, oats

Timing and distribution

• ✅ 4 to 6 doses per day of 20 to 40 g of protein
• ✅ 3 to 5 hour spacing between doses
• ✅ At least 0.3 to 0.4 g/kg per meal to trigger synthesis
• ✅ A pre-bedtime dose (casein) helps overnight recovery

Myths to bury

• ❌ "Too much protein damages kidneys": false in healthy subjects
• ❌ "30-min anabolic window is critical": largely overstated
• ❌ "The body can only absorb 30 g per meal": false
• ❌ "Plant proteins are less effective": with good combos, equivalent

Key takeaways

Protein is the #1 nutritional pillar of any lifter. Aim for 1.6 to 2 g per kg of bodyweight, spread across 4-6 doses. Prioritize whole food sources, supplement with whey if convenience is an issue. Daily total and long-term consistency = muscle building.