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Trainer Toolkit III

Anthropometry & body composition · Screening, vitals & red flags · Programming & load
Jackson & Pollock · Durnin & Womersley · Hodgdon & Beckett · ACSM GETP 11th ed · 2017 ACC/AHA · WHO Asia-Pacific · Calculators work offline
SECTION 08Anthropometry & Body Composition
Everything below runs in the page — type numbers in, get answers, no internet needed. The equations are printed in full further down so you can check any result by hand or use them on paper with a client.

Skinfold body fat calculator

Jackson-Pollock & Durnin-Womersley · ±3.5%
For fat and lean mass

US Navy tape calculator

Hodgdon & Beckett 1984 · ±3–4%
Below larynx
At navel
Women only

BMI, waist & ratios

WHO + Asian/Indian cutoffs

Fat-free mass index (FFMI)

Muscularity relative to height
From the calculators above
Which method should you actually use? Calipers, for almost every client. They cost almost nothing, they are sensitive to real change, and the error is consistent — which is what matters when you are tracking a direction rather than certifying an absolute number. Use the tape method for clients too heavy for the caliper jaws, and for remote coaching. Use a smart scale for nothing except a rough daily trend.

Never quote a body fat number as if it were exact. Say "around 22%, and we will use the same method each time so we can see which way it moves." That sentence protects you and educates them.
The eight skinfold sites — exact landmarks
SiteFold directionExact landmarkUsed inCommon error
Chest / PectoralDiagonalMen: halfway between anterior axillary fold and nipple. Women: one-third of that distance from the axilla.JP3 ♂, JP7Taking it too close to the nipple. Men and women use different points.
MidaxillaryVerticalMidaxillary line, level with the xiphoid process (base of sternum).JP7Drifting forward off the midaxillary line.
TricepsVerticalPosterior midline of the upper arm, halfway between acromion and olecranon, arm relaxed.JP3 ♀, JP7, D-WNot finding the true midpoint. Measure and mark it — do not eyeball.
BicepsVerticalAnterior midline of the upper arm, same level as the triceps site.Durnin-WomersleyTaking it higher up the belly of the muscle.
SubscapularDiagonal, 45°1–2 cm below the inferior angle of the scapula, running down and out at 45°.JP7, D-WNot following the natural 45° cleavage line of the skin.
AbdominalVertical2 cm to the right of the umbilicus. (Some protocols use horizontal — pick one and stay with it.)JP3 ♂, JP7Switching orientation between sessions. Record which you used.
SuprailiacDiagonalJust above the iliac crest, on the anterior axillary line, following the natural angle.JP3 ♀, JP7, D-WGoing too far back toward the flank, or too low onto the crest itself.
ThighVerticalAnterior midline, halfway between inguinal crease and proximal border of patella. Weight on the other leg.JP3, JP7Client bearing weight on the measured leg, which tenses the quad.
Caliper protocol — the rules that decide whether your numbers mean anything
RuleDetailWhy it matters
Right side onlyAll sites on the right side of the body, always.Left–right asymmetry is real. Switching sides invalidates comparison.
Mark the site firstFind the landmark, measure the midpoint, mark with a pen.The single biggest source of test-retest error is site drift.
Pinch 1 cm above the siteGrasp the fold 1 cm proximal, apply calipers at the marked point.Calipers on your fingers reads high.
Read after 2 secondsRelease the caliper fully, wait 1–2 s, read before tissue compresses further.Waiting longer gives a falsely low reading as the fat compresses.
Two readings, then a thirdTake 2 at each site. If they differ by more than 1–2 mm, take a third and use the median.Builds in your own reliability check.
Rotate through sitesDo site 1, 2, 3… then repeat, rather than three times at one site.Repeated pinching at one spot compresses the tissue and drops the reading.
Same conditions every timeSame time of day, similar hydration, not straight after training.Post-training fluid shifts and dehydration both move the numbers.
Same testerIdeally the same person takes every measurement for a given client.Inter-tester error is larger than intra-tester error. Trend beats absolute value.
Calibrated calipersHarpenden, Lange, Slim Guide or equivalent. Check the tension periodically.Cheap plastic calipers have inconsistent spring tension.
Retest every 4–8 weeksNot weekly.Real change is slower than measurement noise. Testing too often shows noise, not progress.
Reliability beats accuracy. A trained tester using consistent technique achieves test-retest reliability within 1–2 mm per site. That matters more than which equation you pick, because you are almost never trying to certify a true body fat percentage — you are trying to detect a 2% change over eight weeks. Same tester, same sites, same conditions, same time of day. Write the protocol down and follow it every time.
Circumference sites — where and how
SiteWhere exactlyClient positionWhat it tells you
NeckJust below the larynx, tape sloping slightly down at the front.Standing, looking straight aheadInput for the Navy formula. Not a progress metric.
ChestAt nipple level, at the end of a normal exhale.Arms relaxed at the sidesUpper-body size. Moves with both muscle and fat.
Waist — narrowestThe natural narrowest point, usually just above the navel.Standing, relaxed, normal exhaleBest for tracking a lean client.
Waist — umbilicalLevel with the navel.Standing, relaxed, normal exhaleThe one to use for risk classification. Repeatable on any body type.
Hip / glutealWidest point of the buttocks.Feet togetherNeeded for waist-to-hip ratio and the female Navy formula.
Arm, relaxedMidpoint between acromion and olecranon, arm hanging.Arm relaxed at the sideTrack this, not the flexed version — it is far more repeatable.
Arm, flexedPeak of the contracted biceps.Elbow at 90°, maximal contractionMotivating for clients. Poor reliability. Use as a bonus, not data.
Thigh, midMidpoint between inguinal crease and top of patella.Weight on the other legMark the height from the floor so you find it again.
CalfWidest point.Standing, weight evenly spreadSlow to change. A useful long-term marker.
Tape technique. Use a non-stretch tape with a spring tension handle if you have one. Snug against skin without compressing. Read at the end of a normal exhale — not a forced one. Take two readings; if they differ by more than 1 cm, take a third. Record the exact site each time (navel vs narrowest waist gives different numbers on the same person).
Every equation, written out
EquationSitesFormulaPopulationStandard error
Jackson-Pollock 3-site ♂Chest, abdomen, thighD = 1.10938 − 0.0008267·S + 0.0000016·S² − 0.0002574·ageMen 18–61 (1978)±3.5%
Jackson-Pollock 3-site ♀Triceps, suprailiac, thighD = 1.0994921 − 0.0009929·S + 0.0000023·S² − 0.0001392·ageWomen 18–55 (1980)±3.5%
Jackson-Pollock 7-site ♂Chest, midaxillary, triceps, subscapular, abdomen, suprailiac, thighD = 1.112 − 0.00043499·S + 0.00000055·S² − 0.00028826·ageMen 18–61 (1978)±3.5%
Jackson-Pollock 7-site ♀Same 7 sitesD = 1.097 − 0.00046971·S + 0.00000056·S² − 0.00012828·ageWomen 18–55 (1980)±3.5%
Durnin-Womersley 4-siteBiceps, triceps, subscapular, suprailiacD = c − m · log₁₀(S), where c and m depend on age band and sex (see table below)Men and women 16–72 (1974)±3.5–5%
Siri conversion%BF = (495 ÷ D) − 450Assumes fat density 0.9007, lean 1.100 g/cm³The standard default
Brozek conversion%BF = (457 ÷ D) − 414.2Slightly different reference body assumptionsWithin ~1% of Siri
US Navy ♂Neck, waist, height (inches)%BF = 86.010·log₁₀(waist − neck) − 70.041·log₁₀(height) + 36.76Hodgdon & Beckett 1984±3–4%
US Navy ♀Neck, waist, hip, height (inches)%BF = 163.205·log₁₀(waist + hip − neck) − 97.684·log₁₀(height) − 78.387Hodgdon & Beckett 1984±3–4%
Durnin-Womersley coefficients by age band
Age bandMales — D =Females — D =
Under 171.1533 − 0.0643 · log₁₀(S)1.1369 − 0.0598 · log₁₀(S)
17–191.1620 − 0.0630 · log₁₀(S)1.1549 − 0.0678 · log₁₀(S)
20–291.1631 − 0.0632 · log₁₀(S)1.1599 − 0.0717 · log₁₀(S)
30–391.1422 − 0.0544 · log₁₀(S)1.1423 − 0.0632 · log₁₀(S)
40–491.1620 − 0.0700 · log₁₀(S)1.1333 − 0.0612 · log₁₀(S)
50 and over1.1715 − 0.0779 · log₁₀(S)1.1339 − 0.0645 · log₁₀(S)
Durnin-Womersley uses the logarithm of the sum of four folds, not the sum itself, and picks its constants from an age band. It was built on a broad, heterogeneous sample aged 16–72, which makes it a reasonable general-purpose choice — but it tends to overestimate body fat in lean, athletic clients. For a trained population, Jackson-Pollock is the better fit.
Method comparison — what each one actually costs you in error
MethodTypical errorCostTimeBest forWatch out for
DEXA±1–3%High15 minThe practical reference standard. Also gives regional and bone data.Hydration and glycogen still move it 1–2%. Scanner-to-scanner differences are real.
Hydrostatic weighing±2–3%High30 minResearch settings.Requires full exhalation underwater. Residual volume estimation adds error.
BodPod (ADP)±2–4%High10 minEasier than hydrostatic, similar accuracy.Facial hair, clothing and body temperature all interfere.
Skinfold calipers±3–5%Very low10 minYour default. Excellent for tracking change over time.Highly tester-dependent. Poor in the obese — folds exceed caliper jaw width.
US Navy tape±3–4%Free3 minQuick screening, obese clients, remote coaching.Blind to muscle. A lean muscular client with a thick neck reads falsely lean.
BIA (smart scale)±5–8%Low1 minDaily trend only, never a single reading.Swings with hydration, food, exercise, time of day. Consumer scales are the worst offenders.
Visual estimation±5–10%FreeInstantA sanity check on a number you already have.Systematically biased. Never quote it as a measurement.
Body fat norms — where a client sits
CategoryMen 20–39Men 40–59Men 60+Women 20–39Women 40–59Women 60+
Essential fat2–5%2–5%2–5%10–13%10–13%10–13%
Athletes6–13%7–14%9–16%14–20%15–21%16–22%
Fitness14–17%15–18%17–20%21–24%22–25%23–26%
Acceptable / average18–24%19–25%21–26%25–31%26–32%27–33%
Obese≥25%≥26%≥27%≥32%≥33%≥34%
BMI and waist — WHO versus Asian cutoffs
ClassificationWHO standard BMIAsian / Indian BMIHealth risk at that BMIWaist — menWaist — women
Underweight<18.5<18.5Raised (nutritional, bone density)
Normal18.5 – 24.918.5 – 22.9Baseline<90 cm<80 cm
Overweight25.0 – 29.923.0 – 24.9Increased90 – 99 cm80 – 87 cm
Obese class I30.0 – 34.925.0 – 29.9High≥100 cm≥88 cm
Obese class II35.0 – 39.930.0 – 34.9Very high
Obese class III≥40≥35Extremely high
This is the most important table on the page for your client base. WHO adopted lower thresholds for Asia-Pacific populations because South Asians develop type 2 diabetes and cardiovascular disease at substantially lower BMI than European populations — more visceral fat and less lean mass at the same weight and height. For Indian adults, overweight starts at 23 and obesity at 25, with waist cutoffs of 90 cm for men and 80 cm for women.

A client at BMI 24 is "normal" by the Western chart and "overweight" by the one that applies to them. Use the right row.

Body mass index

BMI = weight (kg) ÷ height (m)²

Population screening tool. Cannot distinguish muscle from fat — a lean trained client will often read "overweight."

Waist-to-height ratio

WHtR = waist (cm) ÷ height (cm)

Keep it under 0.5. The simplest and one of the best single predictors of cardiometabolic risk, and it needs no chart.

Waist-to-hip ratio

WHR = waist (cm) ÷ hip (cm)

Risk rises above 0.90 in men and 0.85 in women. Captures fat distribution, which BMI misses entirely.

Fat-free mass index

FFMI = lean mass (kg) ÷ height (m)²
Normalised = FFMI + 6.1 × (1.8 − height in m)

Muscularity adjusted for height. Natural ceiling roughly 25 (men) and 21 (women) — a guide, not a verdict.

Lean body mass

LBM = weight × (1 − body fat% ÷ 100)

Set protein targets from this rather than total weight when a client carries a lot of fat.

Ideal weight — Devine

Men: 50 + 2.3 kg per inch over 5 ft
Women: 45.5 + 2.3 kg per inch over 5 ft

A clinical dosing formula, not a physique target. Useful as a reference point, misleading as a goal.

SECTION 09Screening, Vitals & Red Flags
This section exists to keep clients safe and to keep you out of trouble. Screen every client before the first session, document it, and keep the record. The single most defensible thing you can do as a trainer is refer early.
ACSM pre-participation screening — the decision table
Client profileCurrently exercising?Known CV / metabolic / renal disease?Signs or symptoms?Your action
Healthy, no disease, no symptomsNoNoNoStart light-to-moderate. Progress gradually. No clearance needed.
Already training regularlyYesNoNoContinue. Progress as tolerated. No clearance needed.
Sedentary, has diagnosed diseaseNoYesNoMedical clearance before starting. Then begin light-to-moderate.
Training, has diagnosed diseaseYesYesNoClearance if not obtained in the last 12 months. Continue moderate meanwhile.
Any symptoms presentEitherEitherYesStop. Medical clearance required before any exercise.
The 2015 ACSM algorithm deliberately moved away from counting cardiovascular risk factors, because the old approach sent large numbers of low-risk people for unnecessary clearance and became a barrier to exercise. The current logic rests on three things only: current activity level, known disease, and presence of signs or symptoms. Symptoms override everything else.
The symptoms that mean stop and refer
SymptomWhat the client saysWhy it matters
Chest discomfort on exertion"Tightness, pressure or heaviness in my chest when I push"Classic angina pattern. Never train through it.
Unusual breathlessness"I get out of breath doing things I used to manage"Disproportionate dyspnoea suggests cardiac or pulmonary compromise.
Dizziness or fainting"I feel light-headed when I stand or exert myself"Possible arrhythmia, outflow obstruction or blood pressure problem.
Orthopnoea / PND"I have to sleep propped up" / "I wake gasping"Suggestive of heart failure.
Ankle oedema"My ankles swell by the evening"Fluid retention. Cardiac, renal or venous.
Palpitations or racing heart"My heart pounds or skips for no reason"Arrhythmia until proven otherwise.
Intermittent claudication"My calves cramp when I walk, and it eases when I stop"Peripheral arterial disease. Strongly predicts coronary disease.
Known heart murmur"A doctor once heard a murmur"Needs characterisation before vigorous exertion.
Unusual fatigue with normal activity"Ordinary things wipe me out now"Non-specific but meaningful when it is a change from baseline.
Blood pressure — 2017 ACC/AHA categories
CategorySystolicDiastolicExercise implicationYour action
Normal<120and<80No restrictionTrain normally. Recheck annually.
Elevated120–129and<80No restrictionTrain normally. Exercise is the intervention. Recheck in 3–6 months.
Hypertension stage 1130–139or80–89Moderate intensity is safe and beneficialEncourage medical follow-up. Avoid maximal effort and heavy breath-holding.
Hypertension stage 2≥140or≥90Needs medical managementRefer before starting vigorous training. Light-to-moderate aerobic work is usually fine meanwhile.
Do not train today≥180or≥110Postpone the sessionDo not exercise. Recheck after 5 minutes seated. Still high → same-day medical review.
Hypertensive crisis>180and/or>120EmergencyWith symptoms (chest pain, breathlessness, visual change, weakness) → emergency services immediately.
Measure it properly or do not measure it. Client seated five minutes, back supported, feet flat on the floor, arm supported at heart height, correct cuff size, no talking, no caffeine or smoking in the previous 30 minutes. A cuff that is too small reads high and can turn a normal client into a "stage 2" by mistake. Take two readings a minute apart and record the average.
Other vitals worth taking
MeasureNormal adult rangeWell-trainedConcerningHow to take it properly
Resting heart rate60–100 bpm40–60 bpm>100 or <40 with symptomsSeated, 5 min rest, before caffeine. Best measured on waking, over 3 mornings.
Blood pressure<120/80Often lower≥180/110 → do not trainSeated 5 min, back supported, feet flat, arm at heart height, correct cuff size. Two readings a minute apart.
Respiratory rate12–20 /min12–16 /min>24 at restCount without telling them — awareness changes the rate.
SpO₂ (if available)95–100%95–100%<92% at restCold fingers and nail polish both give false lows.
HR recovery (1 min post)>12 bpm drop>20 bpm drop<12 bpm dropA useful free marker of autonomic fitness. Track it over months.
Contraindications — absolute versus relative
LevelConditionWhat you do
── ABSOLUTE — do not train, refer immediately ──
AbsoluteUnstable angina or a recent significant change in anginal patternNo exercise. Urgent medical review.
AbsoluteUncontrolled arrhythmia causing symptoms or haemodynamic compromiseNo exercise until managed.
AbsoluteAcute myocarditis, pericarditis or endocarditisNo exercise. Potentially fatal if trained through.
AbsoluteAcute pulmonary embolism, DVT or recent infarctionNo exercise. Emergency care.
AbsoluteSuspected or known dissecting aneurysmNo exercise. Emergency care.
AbsoluteAcute systemic infection with feverRest until resolved. "Below the neck" symptoms mean no training.
AbsoluteSevere symptomatic aortic stenosisNo exercise without cardiology direction.
AbsoluteUncontrolled heart failureNo exercise until stabilised.
── RELATIVE — proceed only with clearance and modification ──
RelativeKnown coronary artery disease, stableClearance, then moderate intensity with monitoring.
RelativeUncontrolled hypertension (≥180/110)No training until controlled. Light aerobic work once managed.
RelativeUncontrolled diabetes, or blood glucose <70 or >300 mg/dLDo not train at those readings. Feed a low; refer a high.
RelativeAdvanced or complicated pregnancyObstetric clearance. Avoid supine work after the first trimester and any fall risk.
RelativeUncontrolled epilepsyClearance. Avoid overhead loading, free weights and water work unsupervised.
RelativeSevere osteoporosisNo spinal flexion under load, no high-impact work. Loading is still beneficial — just chosen carefully.
RelativeRecent surgery or unhealed injuryWork strictly within the surgeon or physio clearance.
RelativeUncontrolled thyroid diseaseClearance. Both hyper and hypo alter exercise tolerance and HR response.
Medications that change how a client responds to exercise
Drug classCommon examplesEffect on exerciseWhat you change
Beta-blockersMetoprolol, atenolol, propranololBlunts heart rate at rest and during exercise. Lowers max HR.HR-based zones become useless. Switch to RPE and the talk test. Warm up and cool down for longer.
DiureticsFurosemide, hydrochlorothiazideFluid and electrolyte loss; possible arrhythmia and crampsWatch hydration carefully. Avoid heat. Expect more cramping.
ACE inhibitors / ARBsRamipril, losartan, telmisartanLowers BP; can cause post-exercise hypotensionExtend the cool-down. Rise slowly from the floor or a bench.
Calcium channel blockersAmlodipine, diltiazemLowers BP; some reduce HRWatch for dizziness on standing. Longer cool-down.
Insulin / sulfonylureasInsulin, glimepirideReal hypoglycaemia risk during and hours after exerciseHave fast carbs on hand. Do not train on a skipped meal. Avoid injecting into a limb about to be trained.
MetforminMetforminGI upset; long-term B12 depletionTime meals around sessions. Flag B12 for testing.
StatinsAtorvastatin, rosuvastatinMuscle aches in a minority; rarely myopathyNew unexplained muscle pain or dark urine → stop and refer same day.
CorticosteroidsPrednisoloneTendon fragility, muscle loss, raised glucose, bone lossProgress load conservatively. Avoid maximal eccentric and plyometric work.
BronchodilatorsSalbutamol inhalerCan raise HR and cause tremorInhaler present at every session. Longer warm-up reduces exercise-induced bronchoconstriction.
AnticoagulantsWarfarin, apixabanBruising and bleeding riskAvoid contact and fall-risk activities. Any head knock is a medical event.
AntidepressantsSSRIs, tricyclicsTricyclics can raise HR and impair heat toleranceExtra care training in heat. Expect an altered HR response.
Beta-blockers are the one you will meet most often. They cap heart rate, so every HR-based zone you have prescribed becomes meaningless — a client on metoprolol may never reach 60% of their predicted max HR no matter how hard they work. Switch them to RPE and the talk test, and note it on their file so you do not quietly under-dose them for months.
Red flags — stop the session, act now
What happensWhat it might beWhat you do — immediately
Chest pain, pressure or jaw/arm painCardiac eventStop. Sit them down. Call emergency services. Do not let them drive themselves.
Sudden severe headache, "worst ever"HaemorrhageStop. Emergency services.
Face droop, arm weakness, speech difficultyStrokeFAST check. Emergency services. Note the time symptoms started.
Fainting or near-fainting on exertionArrhythmia, outflow obstructionStop the session. Same-day medical review. Do not resume training until cleared.
Sudden shortness of breath out of proportionCardiac, PE, bronchospasmStop. Sit upright. Emergency services if not settling quickly.
Confusion, stopped sweating, hot dry skinHeat strokeEmergency. Cool aggressively — cold water immersion if available.
Audible pop with immediate loss of functionTendon or ligament ruptureStop. Immobilise. Same-day medical assessment.
Dark cola-coloured urine after heavy trainingRhabdomyolysisEmergency. More common after a very hard first session in a deconditioned client.
Numbness, tingling or weakness down a limbNerve root compressionStop that exercise. Refer. Do not "work through" a neurological symptom.
Loss of bladder or bowel control with back painCauda equina syndromeSurgical emergency. Emergency services immediately.
You will get this wrong in one of two directions. Over-referring costs a client some inconvenience and you a little credibility. Under-referring can cost someone their life. Take the first error every time. If your gut says something is wrong, act on it — you are not required to be certain, only careful.
SECTION 10Programming & Load Management

1RM estimator

Six formulas, averaged · most reliable at 2–5 reps
To technical failure, 2–10 ideal
The formulas, and where each one goes wrong
FormulaEquationBest rep rangeBiasNote
Epley1RM = w × (1 + r ÷ 30)2–10Reads high above 6 repsMost widely used. Note it returns 103% at 1 rep — a known quirk.
Brzycki1RM = w × 36 ÷ (37 − r)2–10Reads low above 8 repsBest behaved in the 2–10 range. Breaks down mathematically near 37 reps.
Wathen1RM = 100w ÷ (48.8 + 53.8·e^(−0.075r))1–10Well balancedExponential decay model. Among the most accurate across ranges.
Lombardi1RM = w × r^0.101–10Reads highSimple power function.
O'Conner1RM = w × (1 + 0.025r)1–5ConservativeClose to Brzycki at low reps.
Mayhew1RM = 100w ÷ (52.2 + 41.9·e^(−0.055r))5–10Reads highDeveloped on bench press data.
Average of allMean of the above2–10Cancels individual biasWhat the calculator uses. No single formula is universally best.
You rarely need to test a true 1RM. For most clients it carries more injury risk than it returns in information. Take a set of 3–5 to a hard but clean stop, estimate from that, and re-estimate every few weeks. Testing a genuine max is for competitive lifters with years of technical practice — and even then, in a planned peaking block, not on a whim.
Strength standards — where a client stands
LiftUntrainedNoviceIntermediateAdvancedElite
── MEN — multiples of bodyweight, 1RM ──
Back squat0.75×1.25×1.75×2.25×2.75×+
Bench press0.5×0.75×1.25×1.75×2.0×+
Deadlift1.0×1.5×2.0×2.75×3.25×+
Overhead press0.35×0.55×0.8×1.1×1.4×+
Barbell row0.5×0.75×1.0×1.35×1.75×+
Pull-up (added load)Bodyweight × 5+25% BW+50% BW+75% BW+
── WOMEN — multiples of bodyweight, 1RM ──
Back squat0.5×0.75×1.25×1.75×2.25×+
Bench press0.35×0.5×0.75×1.0×1.35×+
Deadlift0.5×1.0×1.5×2.0×2.5×+
Overhead press0.2×0.35×0.5×0.75×1.0×+
Barbell row0.3×0.5×0.7×0.9×1.2×+
These are approximate multiples of bodyweight, drawn from commonly used trainer references rather than a single controlled dataset. They shift with limb length, weight class and lift technique — a long-femured client will always squat relatively less and deadlift relatively more. Use them to frame a conversation ("you are around intermediate on squat, novice on press — that tells us where to put the work"), never as a verdict on someone.
Session RPE — quantifying load without any equipment
Session RPE (0–10)What it felt likeExampleLoad for a 60 min session
1–2Very easy, recoveryMobility, easy walk60–120 AU
3–4Easy, could repeat itTechnique work, light circuit180–240 AU
5–6Moderate, solid workStandard hypertrophy session300–360 AU
7–8Hard, demandingHeavy compound day, hard intervals420–480 AU
9–10Maximal, could not repeat itTesting day, competition540–600 AU

Session load

Session load (AU) = session RPE × duration in minutes

Ask 30 minutes after the session, not during. One number captures the whole session. AU = arbitrary units.

Acute load

Acute = average daily load over the last 7 days

What the client has done recently — the fatigue side of the equation.

Chronic load

Chronic = average daily load over the last 28 days

What the client is prepared for — the fitness side.

ACWR

ACWR = acute ÷ chronic

Keep it roughly between 0.8 and 1.3. Injuries follow load spikes far more reliably than they follow high absolute load.

Weekly progression cap

Increase weekly load by no more than ~10%

The old rule of thumb, and it holds up reasonably well. Deconditioned clients need less.

Volume load

Volume load = sets × reps × weight

Better than counting sets when intensity varies. Track per muscle group per week.

Acute:chronic workload ratio
Acute : chronic ratioInterpretationInjury riskWhat you do
<0.80Undertrained — detraining zoneElevated (loss of fitness buffer)Build load back gradually. Do not jump straight to previous volumes.
0.80 – 1.30The "sweet spot"LowestKeep going. This is where you want most weeks to sit.
1.30 – 1.50Loading faster than adaptingRisingAcceptable briefly during an intentional overreach. Plan the deload.
>1.50SpikeSubstantially elevatedPull volume back this week. Most injuries follow a load spike, not high load itself.
Treat ACWR as a conversation starter, not a law. The original research was in team sports and has been criticised on statistical grounds since. But the underlying principle survives the criticism intact: sudden increases in load are what hurt people, not high load itself. A client who has trained hard for months tolerates a hard week. A client returning from three weeks off does not.
Warm-up — the five phases
PhaseDurationWhat it isWhySkip it and…
1 · General5–10 minEasy cyclical work — bike, row, brisk walkRaises muscle temperature, blood flow, joint fluid viscosityForce output and tissue compliance stay low
2 · Mobility3–5 minDynamic range work for the joints being trainedRestores usable range without the force loss of long static holdsRange is limited by stiffness, and technique suffers
3 · Activation3–5 minLow-load work for the muscles that tend to stay quietImproves recruitment of glutes, scapular stabilisers, deep corePrime movers take over and compensate
4 · Potentiation2–5 minA few explosive reps — jumps, throws, med ballPost-activation potentiation improves the first working setsYou waste the first two sets warming up anyway
5 · Specific ramp5–10 minThe lift itself: empty bar → 40% → 60% → 80% → working weightRehearses the pattern and primes the nervous system at loadThe most-skipped and most-important step. Injury risk rises sharply
Progression models — how to actually add load
ModelHow it progressesBest forRuns out whenExample
LinearAdd load every sessionBeginners, first 3–9 monthsRecovery cannot keep pace — usually 3–6 monthsSquat 60 → 62.5 → 65 kg each session, 3×5
Double progressionAdd reps to the top of a range, then add load and resetBeginner to intermediate, all accessoriesRarely — it is the most durable model you have3×8–12 at 40 kg. Hit 3×12, go to 45 kg, back to 8.
Weekly undulatingVary intensity and volume across the weekIntermediatesNeeds a longer-term wave layered on topMon heavy 5s · Wed moderate 8s · Fri light 12s
Block periodisationSequential accumulation → intensification → realisationAdvanced, athletes with a competition dateRequires a target date to organise around4 wk volume → 3 wk intensity → 1 wk peak → deload
Autoregulated (RIR/RPE)Load set by daily readiness against a target RIRAnyone who can judge effort accuratelyBeginners cannot self-assess well enough yet"Work up to a top set at RPE 8, then 3 back-offs at 85% of that."
Volume ramp + deloadAdd a set per week, then cut backHypertrophy blocksJunk volume accumulates past a pointWk1 3 sets → Wk2 4 → Wk3 5 → Wk4 deload to 2
When to deload
TriggerWhat you noticeHow urgentWhat to do
ScheduledEvery 4–8 weeks, planned in advancePreventiveCut volume ~50%, keep intensity. Best-case scenario — you never reach the other rows.
Performance stallsSame load feels heavier for 2+ sessionsThis weekReduce volume 40–50% for a week. Hold the loads.
Resting HR up 5+ bpmElevated for 3+ consecutive morningsThis weekDeload. A classic and cheap early warning.
Sleep disturbedTrouble falling asleep, or waking at 3–4 amThis weekDeload. Sympathetic overdrive shows up here first.
Motivation collapsesDreading sessions they normally enjoyNowDeload or take a full rest week. Adherence is worth more than any single block.
Joints ache persistentlyNagging elbow, knee or shoulder pain across sessionsNowDeload and swap to pain-free variations. Do not train through joint pain.
Getting ill repeatedlyRecurrent colds or infectionsNowFull rest week. Chronic high load suppresses immune function.
Client intake — the questions worth asking
AreaWhat to askWhy you are asking
Goal"What do you want to be able to do in six months that you cannot do now?"Behaviour-based answers beat "lose weight." Gives you something to measure and celebrate.
History"What have you tried before? What worked, and what made you stop?"Tells you what to avoid repeating. The reason they quit last time is the reason they will quit again.
MedicalPAR-Q+ plus the symptom list in section 9. Medications and surgeries.Screening and legal protection. Document it and keep it.
Injury"Anything that hurts now, or that used to?"Past injury is the strongest predictor of future injury in the same site.
Availability"Realistically, how many days and how long per session?"Design for the schedule they have, not the one they aspire to.
Sleep"How many hours, and do you wake rested?"Under 6 hours undermines recovery, appetite regulation and adherence.
Stress"How are things outside the gym right now?"Life stress and training stress draw on the same recovery budget.
Food pattern"Walk me through yesterday, from waking to bed."A recall beats a questionnaire. Fewer socially desirable answers.
Activity outside sessions"What does a normal working day look like physically?"NEAT is a bigger lever than the sessions you program.
Support"Who cooks at home? Who else is on board with this?"In Indian households the person cooking often is not the client. Include them or the plan fails.
The last row matters more than it looks. In most Indian households the client is not the person who decides what gets cooked. A nutrition plan handed to someone who does not control their own food is a plan that fails in week two. Ask who cooks, and where possible bring them into the conversation.