Glossary

Metabolism

Metabolism Classification Fundamentals

From BMR through NEAT and EAT to TEF — this is how your TDEE is built. With a system, you can steer it deliberately as a hardgainer.

Notice

This page provides context and guardrails. It is not individual medical, nutrition, or training advice. Suitability and tolerance are individual; for pre-existing conditions, pregnancy/lactation, or medication, consult qualified professionals before making changes.

Term and System View

At a glance Metabolism covers the biochemical processes that produce, convert and store energy. For day-to-day practice, the key number is your TDEE.

BlockShort descriptionGlossary
BMR/RMRBasal/resting energy for essential functionsBasal Metabolic Rate
NEATAll non-exercise movementNEAT
EATPlanned training/exercise expenditureEAT
TEFThermic effect of food (~10%)TEF

TDEE = BMR + NEAT + EAT + TEF

Notice

High NEAT increases your needs — secure your lean surplus consistently.

Practical levers for hardgainers

  • Hit a lean surplus: start with +300–500 kcal (avoid dirty bulks). Recalibrate after 10–14 days based on trend.
  • Protein distribution: 1.8–2.2 g/kg across 3–4 meals (25–35 g per meal; consider the leucine threshold).
  • NEAT corridor: e.g., 7,000–9,000 steps/day in a gaining phase to keep needs predictable.
  • Intensity control: main work at RPE 8–9 (≈ RIR 1–2), assistance at RPE 7–8.
  • Volume & timing: aim for MEV and respect your SRA window; DOMS ≠ progress.
  • Sleep/stress: 7.5–9 h; slow down post-meal, and set a timely caffeine cut-off (caffeine).

Common myths & clarifications

  • “I have an extremely slow metabolism.” Often it’s under-eating, high NEAT, or lack of consistency.
  • “Six meals speed up metabolism.” The TEF relates to amount, not frequency.
  • “More is more.” Too much volume → recovery collapses; stay within MEV/MRV.
MYTH #1

“Hardgainers must eat 6 meals a day”

False. The number of meals is secondary – what matters are total daily calories and protein distribution. Most hardgainers do perfectly fine with 3–4 meals plus shakes, as long as they reach their lean surplus and spread their protein evenly throughout the day. Learn more in the full article: Myth #1.

MYTH #2

“More training = more muscle”

False. Muscle growth follows the equation Growth = Stimulus × Recovery – not Sets × Ego. Hardgainers grow through quality over junk volume: focus on the SRA cycle, RIR control, and balanced MEV/MRV. Learn more in the full article: Myth #2.

Measuring and estimating

  • Indirect calorimetry: very accurate, rarely accessible.
  • Equations + 14-day trend: estimate BMR → derive TDEE → average weight/calories/steps.
  • Fine-tuning: Stalled weight? +150–250 kcal. Too fast a gain? −100–150 kcal.

TDEE ≈ BMR + NEAT + EAT + TEF • TEF ≈ ~10% of calorie intake

Hardgainer Calorie Calculator

No guesswork: BMR → TDEE → Target & macros — precise, practical, hardgainer-specific.

  • BMR → TDEE: Mifflin–St. Jeor × activity factor
  • HG Boost: +0–15% for high NEAT/TEF
  • Targets: Maintenance, Lean Bulk (+10%), Aggressive (+20%)
  • Macros (g/kg): adjustable protein & fat
  • Carbs: auto from remaining kcal
  • Meal split: 3–6× per day (P/F/C per meal)
  • HUD/Dashboard: target kcal, intensity, pie-stack
  • Hydration goal: ~35 ml/kg
  • Guides: Pro tips & glossary links
🔢 Calculate calories and macros
Maintenance Calories Lean Surplus

Use as starting values — refine via 10–14-day trends (weight, steps, energy).

Notice

Descriptive information for orientation — not a treatment, diet or training prescription. Individual differences and possible contraindications apply.

© Hardgainer Performance Nutrition® • Glossary • Updated: Nov 20, 2025