Glossary
Basal Metabolic Rate (BMR)
Definition, formula, worked example — and how a hardgainer uses it to estimate real daily needs.
What is BMR?
In short BMR is the energy your body requires at complete rest — to run breathing, heart function, thermoregulation and vital organs. It’s the starting line for calculating your total daily needs.
Formula (Mifflin–St Jeor) — practical and reliable
Male
BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Female
BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Worked example
Example (male): 75 kg, 180 cm, 25 years
- 10 × 75 = 750
- 6.25 × 180 = 1125
- − 5 × 25 = −125
- + 5 (male)
BMR ≈ 750 + 1125 − 125 + 5 = 1755 kcal/day
From BMR to TDEE
Your Total Daily Energy Expenditure (TDEE) is built from:
- BMR — resting needs
- NEAT — daily activity (walking, posture, fidgeting)
- EAT — planned exercise/training
- TEF — thermic effect of food (typically ~10% of intake)
Common hardgainer trap: calculate BMR, pick an “activity factor” — still end up in a deficit because NEAT is underestimated and intake overestimated.
Practice: estimating your real needs
- 1) Calculate BMR (above) — starting point, not a target.
- 2) Set a starting intake: BMR + 500–700 kcal as an initial estimate for gaining in hardgainers.
- 3) 14-day check: weigh each morning; compare weekly averages.
- 4) Fine-tune: weight flat → add +150–250 kcal; rising too fast → subtract −100–150 kcal.
- 5) Watch NEAT: it often increases with higher intake → needs may climb further.
Common mistakes
- Trusting calculators only: equations are estimates — observe & adjust is mandatory.
- Underestimating portions: too few calories → stalled progress.
- Lots of cardio on the side: pushes NEAT/EAT up → needs rise quietly.
- Low protein: aim for 1.6–2.2 g/kg/day across 3–4 meals.