Trainer Toolkit II — Digestion, Micronutrients & Energy

5 · Digestion map Enzymes Client questions 6 · Vitamins & minerals Interactions Timing 7 · Energy expenditure BMR formulas TDEE breakdown

Read down a column to follow one macronutrient. Read across a row to compare all three at the same stage. The three routes converge only at the very bottom — everything becomes acetyl-CoA and enters the Krebs cycle.

The one structural difference worth remembering: carbohydrate and protein both drain into the hepatic portal vein, so the liver inspects and regulates them before they reach the rest of the body. Fat does not. Chylomicrons are too large for a capillary, so they enter the lymphatic system, travel up the thoracic duct, and join the bloodstream at the left subclavian vein — reaching muscle and adipose tissue before the liver ever sees them. That single anatomical detail explains a great deal about how dietary fat behaves.

Side by side — the comparison table

	Carbohydrate	Protein	Fat
Digestion starts in	Mouth (salivary amylase)	Stomach (pepsin + acid)	Stomach (gastric lipase, partial)
Main site of breakdown	Small intestine + brush border	Small intestine	Small intestine (needs bile)
Key hormone released	Insulin (after absorption)	Gastrin, secretin, CCK	CCK (gallbladder), secretin
End products absorbed	Glucose, fructose, galactose	Amino acids, di/tri-peptides	2-monoglyceride + free fatty acids
Absorption route	Portal vein → liver	Portal vein → liver	Lymph → thoracic duct → blood
Sees the liver first?	Yes	Yes	No — bypasses first-pass
Storage form	Glycogen (~500 g total)	None — no storage pool	Triglyceride in adipose (unlimited)
Storage capacity	~100 g liver + ~400 g muscle	—	Effectively unlimited
Time to clear a meal	1–2 hours	3–6 hours	6–8 hours
Energy yield	4 kcal/g (16.7 kJ/g)	4 kcal/g (16.7 kJ/g)	9 kcal/g (37.7 kJ/g)
Thermic effect (TEF)	5–10% of calories eaten	20–30% — highest of the three	0–3% — lowest
ATP per unit	~30–32 per glucose	Variable, via Krebs	~106 per palmitate (C16)
Satiety per calorie	Low to moderate (fibre helps)	Highest	Moderate — slows emptying
What limits it	Enzyme + transporter capacity	~0.3 g/kg absorbed per hour	Bile availability; fat malabsorption

Every enzyme, where it comes from, what it does

Enzyme / secretion	Where it comes from	Where it acts	What it does	Trigger
── CARBOHYDRATE ──
Salivary amylase (ptyalin)	Salivary glands	Mouth	Starch → maltose + dextrins	Chewing, sight/smell of food
Pancreatic amylase	Pancreas	Duodenum	Starch → maltose, maltotriose, α-limit dextrins	Secretin + CCK
Maltase, sucrase, lactase, isomaltase	Brush border of enterocyte	Small intestine wall	Disaccharides → single sugars	Constitutive
── PROTEIN ──
Hydrochloric acid (HCl)	Parietal cells, stomach	Stomach	Denatures protein, activates pepsinogen	Gastrin, vagus nerve
Pepsin (from pepsinogen)	Chief cells, stomach	Stomach	Protein → polypeptides	Acid pH below 3
Trypsin, chymotrypsin, elastase	Pancreas (as zymogens)	Duodenum	Polypeptides → shorter peptides	CCK; enterokinase activates trypsin
Carboxypeptidase	Pancreas	Duodenum	Cuts amino acids off the C-terminal end	Trypsin activation cascade
Aminopeptidase, dipeptidase	Brush border	Small intestine wall	Peptides → free amino acids	Constitutive
── FAT ──
Lingual lipase	Glands of the tongue	Mouth / stomach	Minor triglyceride breakdown	Chewing
Gastric lipase	Chief cells, stomach	Stomach	10–30% of triglyceride hydrolysed	Presence of fat
Bile salts	Made in liver, stored in gallbladder	Duodenum	Emulsify fat; form micelles. Not an enzyme.	CCK contracts the gallbladder
Pancreatic lipase + colipase	Pancreas	Duodenum	Triglyceride → 2-monoglyceride + 2 FFA	CCK; colipase anchors it past bile
Cholesterol esterase, phospholipase A2	Pancreas	Duodenum	Free cholesterol, lysophospholipids	CCK

The numbers behind the diagram

Energy per gram

Carb 4 kcal (16.7 kJ)
Protein 4 kcal (16.7 kJ)
Fat 9 kcal (37.7 kJ)
Alcohol 7 kcal (29.3 kJ)

Fat carries more than twice the energy per gram. This is the whole reason cooking oil dominates a calorie count.

ATP yield

Glucose → ~30–32 ATP
Palmitate (C16) → ~106 ATP

Fat yields far more ATP per molecule but needs more oxygen per calorie — which is why fat oxidation dominates at low intensity.

Glycogen capacity

Liver ~100 g
Muscle ~400 g
Total ~500 g ≈ 2000 kcal

Roughly one day of fuel. Explains the fast 1–2 kg "loss" in week one of a low-carb diet — glycogen holds ~3 g water per gram.

Thermic effect of food

Protein 20–30%
Carb 5–10%
Fat 0–3%

Eat 100 kcal of protein and you keep only 70–80. This is a genuine, free advantage of a higher-protein diet.

Protein absorption rate

~0.3 g/kg per meal maximises MPS
Whey ~8–10 g/hr appearance

Absorption itself is near-complete. It is the muscle-building response that saturates, not the gut.

Gastric emptying

Carb fastest → protein → fat slowest
Mixed meal: 2–5 hours

Fat and fibre both slow emptying. Useful for satiety; unhelpful immediately pre-training.

What clients actually ask — and what is true

Client question	The honest answer	Why
"Does eating late make me fat?"	No. Total intake decides that, not the clock.	Digestion and storage run the same at 10 pm as at 10 am. Late eating correlates with overeating, which is the real mechanism.
"Should I eat protein within 30 min of training?"	Useful but not urgent. The window is hours, not minutes.	Muscle stays sensitised to protein for ~24 h post-session. Daily total and per-meal distribution matter far more.
"Can my body only absorb 30 g protein at a time?"	No. Absorption is near-complete. Only the muscle-building response plateaus.	The gut absorbs almost everything you eat. ~0.3 g/kg per meal maximises MPS; beyond that the surplus is still used, just not for building.
"Does fat make you fat?"	Only in surplus. But it is the easiest to overeat.	9 kcal/g vs 4, near-zero thermic effect, and it goes straight to storage-capable adipose without a first-pass check.
"Why do I feel sleepy after a big meal?"	Blood flow shifts to the gut, and a big carb load raises tryptophan uptake.	Postprandial somnolence. Larger and more carb-heavy meals produce it more strongly.
"Is a slow metabolism why I am not losing?"	Almost never. Intake reporting is off by 30–50% in most people.	Measured metabolic rate varies only ±10% between similar individuals. Under-reporting of food is the well-documented culprit.
"Do I need to detox?"	Your liver and kidneys already do it, continuously.	No commercial protocol improves on hepatic phase I/II metabolism or renal clearance.
"Should I take MCT oil?"	It is absorbed differently, but it is still 8–9 kcal/g.	Chains under 12 carbons skip the chylomicron and go straight to the portal vein. Faster fuel — not fewer calories.

ICMR-NIN 2020 values first, because those are calibrated to Indian body sizes and diets. US RDAs alongside, because that is what supplement labels print. Where they diverge, the ICMR figure is the one your client actually needs.

Read the iron row carefully. ICMR-NIN 2020 raised the requirement for Indian women to 29 mg/day — against a US RDA of 18 mg. Combined with a phytate-heavy, largely vegetarian, chai-with-every-meal diet, iron deficiency is the most common nutritional problem you will meet in female clients. Fatigue that does not respond to programming changes should send you toward a ferritin test, not a harder session.

Nutrient	ICMR-NIN 2020 RDA — Men	— Women	US RDA — M / F	Upper limit (UL)	Best time to take	Indian food sources	Why a trainer cares
── FAT-SOLUBLE VITAMINS — take with a meal containing fat ──
Vitamin A	1000 µg RAE	840 µg RAE	900 / 700 µg	3000 µg (retinol)	With the fattiest meal	Carrot, pumpkin, spinach, mango, ghee, liver, egg yolk	Vision, immunity, skin. Toxic in excess as retinol — beta-carotene is safe.
Vitamin D	600 IU (15 µg)	600 IU (15 µg)	600 / 600 IU	4000 IU	With the fattiest meal	Sunlight, fortified milk, egg yolk, fatty fish, mushroom	Muscle function, bone, testosterone. Deficiency is very common in India — assume it until tested.
Vitamin E	~10 mg*	~8 mg*	15 / 15 mg	1000 mg	With a fatty meal	Sunflower/safflower oil, almonds, peanuts, sunflower seeds	Antioxidant. High doses antagonise vitamin K — bleeding risk.
Vitamin K	~55 µg*	~55 µg*	120 / 90 µg	No UL set	With a fatty meal; pairs with D	Green leafy veg, natto, fermented foods, some cheeses	Bone and artery calcium routing. K2 works with D3.
── WATER-SOLUBLE VITAMINS — morning, with food ──
Vitamin C	80 mg	65 mg	90 / 75 mg	2000 mg	Any time; with iron	Amla, guava, citrus, capsicum, tomato, drumstick leaves	Doubles or triples non-heme iron absorption. Collagen synthesis.
Thiamine (B1)	1.8 mg	1.7 mg	1.2 / 1.1 mg	No UL set	Morning, with food	Whole grains, pulses, groundnut, sunflower seeds	Carb metabolism. Needs rise with carbohydrate and alcohol intake.
Riboflavin (B2)	2.5 mg	2.4 mg	1.3 / 1.1 mg	No UL set	Morning, with food	Milk, curd, egg, green leafy veg, liver	Energy metabolism. Turns urine bright yellow — harmless, and a useful adherence check.
Niacin (B3)	18 mg	14 mg	16 / 14 mg	35 mg (as supplement)	With food — avoid empty stomach	Groundnut, chicken, fish, whole grains, mushroom	Flushing above ~50 mg is common and harmless but alarming to clients.
Vitamin B6	2.4 mg	1.9 mg	1.3 / 1.3 mg	100 mg	Morning, with food	Banana, chana, potato, chicken, fish, sunflower seeds	Amino acid metabolism. Chronic high doses cause peripheral neuropathy.
Folate (B9)	300 µg DFE	220 µg DFE	400 / 400 µg	1000 µg (synthetic)	Morning, with food	Green leafy veg, pulses, beetroot, citrus, liver	High folate masks B12 deficiency — test B12 before loading folate.
Vitamin B12	2.2 µg	2.2 µg	2.4 / 2.4 µg	No UL set	Morning, empty stomach ideal	Only animal foods: milk, curd, paneer, egg, meat, fish	Vegetarian and vegan clients will be deficient without supplementation. Extremely common in India.
── MAJOR MINERALS ──
Calcium	1000 mg	1000 mg	1000 / 1000 mg	2500 mg	Split doses, with food	Milk, curd, paneer, ragi, sesame, drumstick leaves	Only ~500 mg absorbs at once — split it. Blocks iron; keep them apart.
Magnesium	440 mg	370 mg	400 / 310 mg	350 mg (supplemental only)	Evening — mildly relaxing	Whole grains, pulses, nuts, seeds, dark leafy veg	Needed to activate vitamin D. Involved in 300+ enzyme reactions. Citrate and glycinate absorb best.
Phosphorus	~1000 mg*	~1000 mg*	700 / 700 mg	4000 mg	With food	Milk, pulses, nuts, whole grains, meat	Rarely deficient. Excess from cola and processed food disturbs the calcium ratio.
── TRACE MINERALS ──
Iron	19 mg	29 mg	8 / 18 mg	45 mg	Empty stomach + vitamin C	Green leafy veg, pulses, jaggery, dates, red meat, liver	Women need 29 mg — the single biggest gap in Indian diets. Screen female clients with fatigue.
Zinc	17 mg	13.2 mg	11 / 8 mg	40 mg	With food, away from iron	Pulses, whole grains, sesame, cashew, meat, shellfish	Testosterone, immunity, wound healing. Long-term high doses deplete copper.
Iodine	150 µg	150 µg	150 / 150 µg	1100 µg	With food	Iodised salt, seafood, dairy	Thyroid function, and therefore metabolic rate. Iodised salt has largely solved this in India.
Selenium	~40 µg*	~40 µg*	55 / 55 µg	400 µg	With food	Brazil nuts, seafood, egg, whole grains	Thyroid hormone conversion. Narrow safe range — 2 Brazil nuts is a full dose.
Copper	~1.7 mg*	~1.4 mg*	0.9 / 0.9 mg	10 mg	With food; pair with zinc	Cashew, sesame, whole grains, shellfish, dark chocolate	Depleted by long-term zinc supplementation. Include 1–2 mg if zinc is above 25 mg.
Potassium	~3500 mg*	~3500 mg*	3400 / 2600 mg	No UL (food)	Spread through the day	Banana, coconut water, potato, pulses, leafy veg	Blood pressure, cramping, fluid balance. Most Indian diets fall short.
Sodium	<2000 mg	<2000 mg	<2300 mg	—	With food	Salt, papad, pickle, namkeen, processed food	Needs go up with heavy sweating. Do not blanket-restrict an athlete training in Indian heat.

* Marked values are approximate or drawn from international sources where ICMR-NIN 2020 does not publish a separate Indian RDA. Reference bodyweights: ICMR figures assume a 65 kg man and 55 kg woman aged 20–39. EAR vs RDA: ICMR-NIN now recommends using the EAR (roughly 80% of the RDA) for planning individual diets; the RDA is for correcting deficiency.

Interactions — what blocks what

Combination	Effect	Size of effect	What to do	Confidence
── AVOID TOGETHER ──
Iron + Calcium	Calcium blocks iron absorption	Up to −62% in a single meal	Separate by 2–4 hours. Iron in the morning, calcium at night.	Strong
Iron + Tea / Coffee	Tannins and polyphenols bind iron	Up to −60%	No chai within 1 hour either side of an iron-rich meal. Big one for Indian clients.	Strong
Iron + Zinc (high dose)	Compete for the same transporter	Meaningful above 25 mg iron	Separate by 2 hours, or take with food to blunt the competition.	Moderate
Zinc (long-term, high) + Copper	Zinc induces metallothionein, traps copper	>40 mg/day zinc over months	Add 1–2 mg copper if zinc exceeds 25 mg/day long term.	Strong
Calcium + Iron-rich plant meal	Reduces non-heme iron uptake	Substantial	Do not give a milk/curd-heavy meal alongside the iron supplement.	Strong
Vitamin E (high dose) + Vitamin K	E antagonises K-dependent clotting	Above ~400 IU vitamin E	Avoid high-dose E, especially with any blood thinner.	Moderate
Folate (high) + B12 status	Masks B12 deficiency on a blood count	Clinically important	Check B12 before starting high-dose folate. Neurological damage progresses silently.	Strong
Phytates + Iron / Zinc	Phytic acid chelates both minerals	−30 to −60%	Soak, sprout or ferment pulses and grains. Idli and dosa batter is already fermented — an advantage.	Strong
Oxalates (spinach) + Calcium / Iron	Binds both into unabsorbable salts	Large for that meal	Palak is a poor calcium source despite the numbers. Cook and pair with vitamin C.	Strong
── TAKE TOGETHER ──
Iron + Vitamin C	C reduces Fe³⁺ to absorbable Fe²⁺	+200 to +300%	Lemon on dal. Amla or guava with the meal. The cheapest intervention you have.	Strong
Vitamin D + Calcium	D drives intestinal calcium uptake	Substantial	Give together, with a fat-containing meal.	Strong
Vitamin D + Magnesium	Mg activates D through both hydroxylation steps	Required, not optional	Correcting magnesium often fixes a stubbornly low vitamin D.	Moderate–Strong
Vitamin D3 + K2	D raises calcium; K2 directs it to bone not artery	Emerging evidence	Reasonable pairing at higher D doses. Not yet settled.	Moderate
Fat-soluble vitamins + dietary fat	Absorption requires micelle formation	Can be −50% without fat	Never with black coffee on an empty stomach. Always with a proper meal.	Strong
Heme iron + non-heme iron	"Meat factor" enhances plant iron uptake	+150%	A small amount of meat or fish lifts iron from the whole meal.	Strong
Protein + Carbohydrate post-workout	Insulin aids amino acid and glycogen uptake	Modest for MPS, real for glycogen	Matters most for twice-daily training or endurance athletes.	Moderate

Your instinct about iron and calcium was right. Calcium interferes with both heme and non-heme iron absorption, apparently by competing at the DMT1 transporter, and a single co-ingested dose can cut iron uptake by up to 62%. Separate them by 2–4 hours.

The bigger practical problem in India is chai. Tea polyphenols can cut iron absorption by up to 60%, and most clients drink it with or immediately after meals. Moving chai to one hour away from the main meal is often a larger intervention than any supplement.

When to take what

Time of day	What to take	Why then	Watch out for
On waking, empty stomach	Iron (with vitamin C or lemon water)	No competing minerals, no food-bound inhibitors	Nausea in some. If so, take with food and accept less absorption.
Breakfast	B-complex, vitamin C, B12	B vitamins can be mildly stimulating; food prevents nausea	Keep chai 1 hour away if iron was taken earlier.
Largest / fattiest meal	Vitamin D, A, E, K, omega-3, CoQ10	Fat-soluble — needs bile and dietary fat to absorb	A fat-free meal can cut absorption by half.
With lunch and dinner	Zinc, calcium (split), multivitamin	Food buffers gastric irritation; splitting calcium raises total uptake	Do not pair calcium with the iron dose.
Pre-workout (30–60 min)	Caffeine, creatine (timing flexible), beta-alanine	Peak plasma caffeine at ~45–60 min	Creatine timing is irrelevant — only daily consistency matters.
Post-workout	Protein, carbohydrate, creatine (if preferred)	Convenience and adherence more than physiology	The "anabolic window" is hours wide, not 30 minutes.
Evening / before bed	Magnesium, casein or curd	Magnesium is mildly calming; slow protein overnight	Magnesium oxide is poorly absorbed and laxative. Use citrate or glycinate.

Deficiency signs — pattern recognition, then refer

Stay in your lane. You are a trainer, not a physician. Your job is to notice a pattern, ask the right question, and send the client to someone who can test and treat. Never diagnose, and never put a client on therapeutic-dose iron, vitamin D or anything else on your own judgement.

What you notice in the client	Likely nutrient	Confirm with	What you do (you are not a doctor)
Persistent fatigue, pale inner eyelid, breathless on stairs	Iron (± B12, folate)	CBC, ferritin, transferrin saturation	Refer for testing. Do not supplement iron blind — overload is harmful.
Vegetarian, tingling hands/feet, poor memory	Vitamin B12	Serum B12, homocysteine, MMA	Refer. Nearly all long-term Indian vegetarians need supplementation.
Bone or muscle ache, weak on squats, low mood, indoor job	Vitamin D	Serum 25(OH)D	Very common in India. Refer for testing; sunlight is rarely sufficient in urban life.
Cramping during or after sessions	Magnesium, sodium, potassium, or simply hydration	Usually clinical, not lab	Check fluid and salt intake first — that is the usual answer, not a mineral deficit.
Cuts heal slowly, frequent colds, poor appetite	Zinc	Serum zinc (unreliable), clinical picture	Review dietary intake before supplementing. Refer if persistent.
Cold intolerance, weight gain despite adherence, fatigue	Iodine / thyroid function	TSH, free T4	Refer. Do not adjust calories further until thyroid is ruled out.
Bleeding gums, easy bruising, poor recovery	Vitamin C	Clinical; serum ascorbate	Rare in India given the diet. Review actual fruit and vegetable intake.

Every MET value below is from the 2024 Adult Compendium of Physical Activities, the reference standard for activity energy cost. Calorie columns are calculated, not estimated — three body weights so you can read a client off the table directly.

What one MET is

1 MET = 3.5 ml O₂ / kg / min
= 1 kcal / kg / hour
= 4.184 kJ / kg / hour

One MET is roughly the cost of sitting quietly. A 4-MET activity costs four times that.

MET → calories per minute

kcal/min = MET × 3.5 × kg ÷ 200

The one formula to memorise. For a 70 kg client it simplifies to kcal/min ≈ MET × 1.225.

MET → kilojoules

kJ = kcal × 4.184
kJ/min = MET × 3.5 × kg ÷ 200 × 4.184

SI unit. 1 kcal = 4.184 kJ exactly. Some clients and most food labels outside the US use kJ.

Quick estimate for walking

kcal/km ≈ 0.5 × bodyweight in kg

A 70 kg client burns roughly 35 kcal per kilometre walked, near enough for programming.

Steps to calories

10,000 steps ≈ 7–8 km ≈ 300–400 kcal
for a 70 kg adult

Depends heavily on stride and pace, but the right order of magnitude for setting a step target.

Excess post-exercise O₂

EPOC ≈ 6–15% of session cost

Real, but small. A 400 kcal session buys perhaps 25–60 kcal extra. Do not let clients bank on "afterburn".

The full activity table — MET, kcal and kJ

Activity	MET	30 min 60 kg	30 min 70 kg	30 min 85 kg	1 hour 70 kg (kcal)	1 hour 70 kg (kJ)	Coaching note
SLEEP & SEDENTARY — where most of the day goes
Sleeping	1.0	32	37	45	74	308	The baseline. ~1 kcal/min for a 70 kg adult.
Lying quietly, watching TV	1.0	32	37	45	74	308
Sitting quietly	1.0	32	37	45	74	308	A desk job is ~8 hours at close to this.
Sitting at a desk, working	1.3	41	48	58	96	400
Sitting, fidgeting	1.5	47	55	67	110	461	Fidgeting is real NEAT — it adds up over a year.
Standing quietly (in a queue)	1.3	41	48	58	96	400
Standing, fidgeting	1.5	47	55	67	110	461	A standing desk buys ~0.3 METs. Modest, not magic.
Driving a car	1.8	57	66	80	132	554
SELF CARE & DAILY LIVING
Eating, sitting	1.5	47	55	67	110	461
Bathing, sitting	1.5	47	55	67	110	461
Grooming, brushing teeth, shaving	2.0	63	74	89	147	615
Showering, toweling off, standing	2.0	63	74	89	147	615
Dressing, undressing	2.8	88	103	125	206	861
Getting ready for bed	2.3	72	85	103	169	707
HOUSEHOLD — the ADLs your client already does
Washing dishes, standing	2.0	63	74	89	147	615
Ironing	1.8	57	66	80	132	554
Cooking, standing, light effort	2.0	63	74	89	147	615
Cooking, moderate effort	3.5	110	129	156	257	1076	An hour of real cooking is a genuine 250+ kcal.
Laundry, folding, hanging clothes	2.3	72	85	103	169	707
Cleaning, sweeping, light effort	2.3	72	85	103	169	707
Sweeping (jhaadu), fast, moderate	3.8	120	140	170	279	1169	Traditional bent-over sweeping is harder than a broom.
Mopping (pocha), standing, moderate	3.5	110	129	156	257	1076
Scrubbing floors on hands and knees	3.5	110	129	156	257	1076	Vigorous version reaches 6.5 METs.
Vacuuming, moderate	3.0	94	110	134	220	923
Making the bed, changing linen	3.0	94	110	134	220	923
Food shopping with a cart	3.3	104	121	147	243	1015
Carrying groceries on level ground	3.5	110	129	156	257	1076
Carrying groceries upstairs	5.3	167	195	237	390	1630
Multiple household tasks, vigorous	4.3	135	158	192	316	1322
Moving furniture, carrying boxes	5.8	183	213	259	426	1784
Childcare, standing, dressing/feeding	3.5	110	129	156	257	1076
Playing with children, vigorous	5.8	183	213	259	426	1784	A parent client is doing more than they think.
Gardening, general	3.8	120	140	170	279	1169
WALKING — your most-prescribed tool
Walking, household	2.3	72	85	103	169	707
Walking, strolling, <2.0 mph (3.2 km/h)	2.3	72	85	103	169	707	Too slow to count as moderate intensity.
Walking, 2.5 mph (4.0 km/h), level	3.0	94	110	134	220	923	The bottom edge of 'moderate'.
Walking, 3.0 mph (4.8 km/h), moderate	3.8	120	140	170	279	1169	A normal comfortable pace.
Walking, 3.5 mph (5.6 km/h), brisk	4.8	151	176	214	353	1476	This is what 'brisk walk' should mean.
Walking, 4.0 mph (6.4 km/h), very brisk	5.5	173	202	245	404	1691
Walking, 4.5 mph (7.2 km/h)	7.0	220	257	312	514	2153	Most people break into a jog before this.
Walking the dog	3.0	94	110	134	220	923
Walking with a daypack, level	3.5	110	129	156	257	1076
Walking, treadmill 3.0 mph, 0% grade	3.8	120	140	170	279	1169
Walking, treadmill 3.5 mph, 0% grade	4.8	151	176	214	353	1476
Nordic walking with poles, moderate	5.3	167	195	237	390	1630	Poles add ~1 MET over the same speed. Good for deconditioned clients.
Stair climbing, slow pace	4.5	142	165	201	331	1384
Stair climbing, general	6.8	214	250	303	500	2091
Stair climbing, fast pace	9.3	293	342	415	684	2860	Free interval training in any apartment block.
Descending stairs	3.5	110	129	156	257	1076
Climbing hills, no load, 1–5% grade	5.3	167	195	237	390	1630
Climbing hills, no load, 6–10% grade	7.0	220	257	312	514	2153
Carrying a 5–14 lb load, level ground	4.0	126	147	178	294	1230
Carrying a 25–49 lb load, upstairs	8.0	252	294	357	588	2460
GYM & CONDITIONING
Stretching, mild	2.3	72	85	103	169	707	Not a calorie-burning activity. Program it for other reasons.
Yoga, Hatha	2.3	72	85	103	169	707
Yoga, Surya Namaskar	3.5	110	129	156	257	1076
Yoga, Power	4.0	126	147	178	294	1230
Yoga, Hatha, high intensity	8.0	252	294	357	588	2460
Pilates, mat	1.8	57	66	80	132	554
Bodyweight exercises, general	3.0	94	110	134	220	923
Resistance training, 8–15 reps, varied load	3.5	110	129	156	257	1076	Typical hypertrophy session with normal rest.
Circuit training, light effort	3.5	110	129	156	257	1076
Calisthenics, moderate effort	3.8	120	140	170	279	1169
Resistance training, squats and deadlifts	5.0	158	184	223	368	1538
Circuit training, moderate effort	5.0	158	184	223	368	1538
Elliptical trainer, moderate	5.0	158	184	223	368	1538
Resistance training, vigorous / bodybuilding	6.0	189	220	268	441	1845	Short rests, big compounds, real intent.
Circuit training, body weight	6.0	189	220	268	441	1845
Bodyweight exercises, high intensity	6.5	205	239	290	478	1999
High intensity interval exercise, moderate	7.0	220	257	312	514	2153
Rowing ergometer, vigorous	7.3	230	268	326	537	2245
Calisthenics, vigorous (burpees, battle ropes)	7.5	236	276	335	551	2306
Circuit with kettlebells, vigorous	7.5	236	276	335	551	2306
Elliptical trainer, vigorous	9.0	284	331	402	662	2768
Stair treadmill ergometer (stairmaster)	9.3	293	342	415	684	2860
Kettlebell swings	9.8	309	360	437	720	3014	One of the highest MET values in the whole gym section.
Rope skipping, general	11.0	346	404	491	808	3383
HIIT — burpees, mountain climbers, Tabata	11.0	346	404	491	808	3383	But sustained for minutes, not an hour.
Rowing ergometer, ≥200 watts	14.0	441	514	625	1029	4305
CARDIO — running and cycling
Jogging 2.6–3.7 mph, very slow	3.3	104	121	147	243	1015
Jogging in place	4.8	151	176	214	353	1476
Running, 4.0–4.2 mph (13 min/mile)	6.5	205	239	290	478	1999
Jogging, general, self-selected pace	7.5	236	276	335	551	2306
Running, 5.0 mph (12 min/mile)	8.5	268	312	379	625	2614
Running, 6.0 mph (10 min/mile)	9.3	293	342	415	684	2860
Running, 6.7 mph (9 min/mile)	10.5	331	386	469	772	3229
Running, 7.5 mph (8 min/mile)	11.8	372	434	527	867	3629
Running, 9.0 mph (6.5 min/mile)	13.0	410	478	580	956	3998
Running, marathon pace	13.3	419	489	594	978	4090
Running, stairs, up	15.0	472	551	669	1102	4613
Cycling, stationary, 50 watts, light	4.0	126	147	178	294	1230
Cycling, leisure, <10 mph	4.0	126	147	178	294	1230
Cycling, stationary, 90–100 watts	6.0	189	220	268	441	1845
Cycling, general	7.0	220	257	312	514	2153
Cycling, 12–13.9 mph, moderate	8.0	252	294	357	588	2460
Cycling, spin bike class	9.0	284	331	402	662	2768
Cycling, 14–15.9 mph, vigorous	10.0	315	368	446	735	3075
Cycling, stationary, 200–229 watts	10.8	340	397	482	794	3321
Swimming, leisurely, general	6.0	189	220	268	441	1845
Swimming, freestyle, moderate	8.3	261	305	370	610	2552
Swimming, freestyle, vigorous	9.8	309	360	437	720	3014
SPORTS
Billiards	2.5	79	92	112	184	769
Bowling	3.0	94	110	134	220	923
Tai chi, qi gong	3.3	104	121	147	243	1015
Table tennis	4.0	126	147	178	294	1230
Volleyball, non-competitive	3.0	94	110	134	220	923
Golf, walking, carrying clubs	4.3	135	158	192	316	1322
Cricket, batting, bowling, fielding	4.8	151	176	214	353	1476
Tennis, doubles	4.5	142	165	201	331	1384
Badminton, social singles/doubles	5.5	173	202	245	404	1691
Basketball, shooting baskets	5.0	158	184	223	368	1538
Tennis, general, moderate	6.8	214	250	303	500	2091
Soccer / football, casual	7.0	220	257	312	514	2153
Kickboxing	7.3	230	268	326	537	2245
Basketball, general	7.5	236	276	335	551	2306
Badminton, competitive match play	9.0	284	331	402	662	2768
Soccer / football, competitive	9.5	299	349	424	698	2921
Martial arts, moderate pace	10.3	324	379	460	757	3167
Squash	12.0	378	441	536	882	3690
Boxing, in ring	12.3	387	452	549	904	3783

These values already include resting metabolism. A 4-MET activity for one hour is the gross cost. If you want the true additional expenditure above what the client would have burned sitting anyway, subtract 1 MET. For a 70 kg client that is about 70 kcal per hour — worth doing when you are calculating a precise deficit, ignorable for general programming.

What this table tells you about programming. An hour of hard resistance training sits at 5–6 METs — roughly 370–440 kcal for a 70 kg client. A brisk 45-minute walk at 4.8 METs is around 265 kcal. But a client who adds 4000 steps a day, takes stairs, and cooks their own food can add 300–500 kcal daily without any session at all. Over a week that beats the training. Prescribe NEAT as deliberately as you prescribe sets and reps.

Calculating requirement — which equation to use

Equation	Formula	Needs	Accuracy	When to use it
Mifflin-St Jeor Default	M: (10 × kg) + (6.25 × cm) − (5 × age) + 5 F: (10 × kg) + (6.25 × cm) − (5 × age) − 161	Weight, height, age, sex	Within 10% of measured in more people than any other equation	Your default for every client. 2005 systematic review found it the most accurate for the general population.
Katch-McArdle	370 + (21.6 × lean body mass in kg)	Lean mass — needs a body fat measurement	Best if body fat is measured properly; worse if estimated	Use when you have a DEXA or reliable calipers. Sidesteps the muscle-mass problem entirely.
Cunningham	500 + (22 × lean body mass in kg)	Lean mass	Better than Mifflin in lean, trained athletes	Athletic and very muscular clients. Runs higher than Katch-McArdle.
Harris-Benedict (revised)	M: 88.36 + (13.40 × kg) + (4.80 × cm) − (5.68 × age) F: 447.59 + (9.25 × kg) + (3.10 × cm) − (4.33 × age)	Weight, height, age, sex	Overestimates by 5–15% in modern sedentary adults	Legacy. Still in many apps. Know it so you can recognise inflated numbers.
ICMR-NIN adjustment	Take the calculated BMR and reduce by 10%	Any of the above	Correction, not an equation	Relevant to your clients. ICMR-NIN 2020 found FAO/WHO equations overestimate Indian BMR by 10–12% — Indians carry proportionally more fat at the same weight.

Answer to your question: yes, Mifflin-St Jeor. A 2005 systematic review found it predicted resting metabolic rate within 10% of measured values in more people than any other equation, and it remains the ADA/Academy of Nutrition and Dietetics recommendation for non-obese and obese adults alike. Use Katch-McArdle only when you have a genuine body-fat measurement — if you are estimating body fat by eye, the error you introduce is larger than the error you were trying to fix.

For Indian clients, apply the ICMR-NIN 10% downward correction. Then treat whatever number you get as a starting hypothesis, not a fact.

Worked example — 32-year-old man, 78 kg, 175 cm, trains 4×/week

Step 1 — BMR (Mifflin-St Jeor): (10 × 78) + (6.25 × 175) − (5 × 32) + 5 = 780 + 1094 − 160 + 5 = 1719 kcal
Step 2 — Indian adjustment: 1719 × 0.90 = 1547 kcal
Step 3 — PAL (moderately active, 1.65): 1547 × 1.65 = 2552 kcal/day maintenance (10,679 kJ)
Step 4 — Goal. Fat loss at 0.6% BW/week → ~470 g/week → deficit ≈ 500 kcal/day → target ~2050 kcal
Step 5 — Protein first: 2.0 g/kg = 156 g protein (624 kcal). Fat at 25% = 57 g (513 kcal). Carbs get the remainder = 229 g.

Step 6 — the step everyone skips. Weigh him weekly for two weeks and compare actual change against predicted. Every equation carries ±10% error, which is ±250 kcal here. The scale is the real measurement; the formula only tells you where to start.

Where the calories actually go

Component	Share of TDEE	Range	Can you change it?	How
BMR / RMR	60–70%	Varies ±10% between similar people	Slowly and slightly	More lean mass. ~13 kcal/day per kg of muscle. Real but slow — do not oversell it.
TEF — thermic effect of food	~10%	8–15% depending on diet	Yes, modestly	Raise protein. Protein costs 20–30% of its own calories to process; fat costs almost nothing.
NEAT — non-exercise activity	15–30%	Can vary 2000 kcal/day between people	Yes — the biggest lever	Steps, standing, fidgeting, taking stairs. NEAT drops in a deficit — this is why plateaus happen.
EAT — exercise activity	5–15%	Highly variable	Yes, but bounded	An hour of hard training is 400–600 kcal. Less than most clients assume, and less than NEAT over a week.

Activity level	PAL multiplier	ICMR-NIN 2020 value	What it actually looks like	70 kg male, BMR 1650
Sedentary	1.2 – 1.4	1.40	Desk job, car commute, no structured exercise, under 5000 steps	1980 – 2310 kcal
Lightly active	1.4 – 1.6	~1.60	Desk job plus 2–3 light sessions a week, 6000–8000 steps	2310 – 2640 kcal
Moderately active	1.6 – 1.75	1.70 (moderate work)	Training 4–5 days a week, or a job on their feet, 8000–12000 steps	2640 – 2890 kcal
Very active	1.75 – 2.0	~1.90	Daily hard training, or physical labour plus training	2890 – 3300 kcal
Extremely active	2.0 – 2.4	2.10 (heavy work)	Twice-daily training, manual labour, endurance athletes in a build	3300 – 3960 kcal

Why clients plateau. In a sustained deficit, NEAT falls — often substantially and always unconsciously. They move less, fidget less, take the lift. Measured drops of 300–500 kcal/day are documented. This is metabolic adaptation, and it is mostly behavioural rather than a broken metabolism. The fix is a step target you can actually verify, not a further calorie cut.

Sources. MET values: Herrmann SD, Willis EA, Ainsworth BE, et al. 2024 Adult Compendium of Physical Activities: A third update of the energy costs of human activities. J Sport Health Sci. 2024;13(1):6-12. Full database at pacompendium.com. BMR equations: Mifflin MD, St Jeor ST, et al. Am J Clin Nutr 1990;51:241-7. Frankenfield D, Roth-Yousey L, Compher C. J Am Diet Assoc 2005;105:775-89 (systematic review favouring Mifflin-St Jeor). Indian requirements and BMR correction: ICMR-NIN Expert Group on Nutrient Requirements for Indians, RDA and EAR, 2020. Reference man 65 kg, reference woman 55 kg. Digestion and absorption: Gropper SS, Smith JL, Carr TP, Advanced Nutrition and Human Metabolism, 8th ed; Hall JE, Guyton and Hall Textbook of Medical Physiology, 14th ed. Micronutrient interactions: Sandström B. Micronutrient interactions: effects on absorption and bioavailability. Br J Nutr 2001;85(S2):S181-5. Hallberg L et al. on calcium–iron inhibition; Hurrell RF et al. on polyphenol inhibition of iron absorption.

Scope. A coaching reference for healthy adults. Nothing here is a diagnosis, a prescription, or a substitute for medical care. Do not initiate therapeutic-dose supplementation on your own judgement — refer to a physician or registered dietitian for testing and treatment.

Prepared for Manu · August 2026 · Companion to Trainer Toolkit I