Every layer of the engine ties to peer-reviewed evidence. Filter by category. Every paper is real, traceable, and clickable to PubMed/DOI.
BMR · Energy
A new predictive equation for resting energy expenditure in healthy individuals
Mifflin MD, St Jeor ST et al. · Am J Clin Nutr · 1990 · 51(2):241-247 · DOI: 10.1093/ajcn/51.2.241
Empirical regression on N=498 healthy adults. New equation: BMR = 10·W + 6.25·H − 5·A + s (s = +5 M, −161 F). ACSM gold standard for 36 years.
Drives BMR computation for every Body-ID. Engine output ±10% of measured RMR for ~82% of healthy adults.
BMR · Energy
World Health Organization equations have shortcomings for predicting resting energy expenditure
Müller MJ et al. · Am J Clin Nutr · 2004 · 80(5):1379-1390 · DOI: 10.1093/ajcn/80.5.1379
BMI-stratified accuracy comparison. Mifflin outperforms WHO/FAO and Harris-Benedict across BMI bands.
Validates Mifflin as our baseline. WHO/FAO used as cross-check for outliers (BMI > 35).
BMR · Energy
Basal metabolic rate studies in humans: measurement and development of new equations
Henry CJ. · Public Health Nutr · 2005 · 8(7A):1133-1152 · DOI: 10.1079/PHN2005801
Oxford equations stratified for ethnicity. Validated for South Asian populations.
Cross-validation for Indian / South Asian client BMR estimates. Falls within ±2% of Mifflin for our cohort.
BMR · Energy
A reappraisal of the caloric requirements of men
Owen OE et al. · Am J Clin Nutr · 1987 · 46(6):875-885 · DOI: 10.1093/ajcn/46.6.875
Height-independent simplification. BMR can be reasonably predicted from weight alone.
Sanity-check formula. Engine flags BMR estimates that diverge >15% between Mifflin and Owen for manual review.
BMR · Energy
A reanalysis of the factors influencing basal metabolic rate in normal adults
Cunningham JJ. · Am J Clin Nutr · 1980 · 33(11):2372-2374 · DOI: 10.1093/ajcn/33.11.2372
Lean body mass-based BMR. RMR = 500 + 22·LBM (kg). Best fit for athletes.
Used for elite athletes (LBM > bodyweight 80th percentile). Lean-mass tracking unlocks this layer.
Adaptive Thermogenesis
Changes in energy expenditure resulting from altered body weight
Leibel RL, Rosenbaum M, Hirsch J. · N Engl J Med · 1995 · 332(10):621-628 · DOI: 10.1056/NEJM199503093321001
Landmark paper: after 10% weight loss, BMR drops ~15% beyond what Mifflin predicts. This is Adaptive Thermogenesis.
Foundation of FBM's plateau prediction. We pre-bake a 12.5% AT into Week-8+ deficits and trigger refeed.
Adaptive Thermogenesis
Adaptive thermogenesis in humans
Rosenbaum M, Leibel RL. · Int J Obes · 2010 · 34(Suppl 1):S47-S55 · DOI: 10.1038/ijo.2010.184
~10% sustained AT post-weight-loss persists for years. Reverse-diet protocols are not optional — they're physiology.
Drives FBM's 8-week reverse-diet protocol post-cut. Calorie ramp +50 kcal/wk derived from AT half-life.
Adaptive Thermogenesis
Changes in energy expenditure with weight gain and weight loss in humans
Müller MJ, Enderle J, Bosy-Westphal A. · Curr Obes Rep · 2016 · 5(4):413-423 · DOI: 10.1007/s13679-016-0237-4
AT magnitude 10–15% during active deficit, 5–10% sustained. Plateau half-life 8–12 weeks.
Cited as our exact source for the "Week 8" plateau warning shown on every cutting plan.
Adaptive Thermogenesis
Persistent metabolic adaptation 6 years after "The Biggest Loser" competition
Fothergill E et al. · Obesity · 2016 · 24(8):1612-1619 · DOI: 10.1002/oby.21538
Extreme deficit subjects showed 25–30% AT, sustained 6 years post-competition. Crash diets cause persistent damage.
Hard ceiling on FBM cuts: if AT > 25%, engine triggers mandatory maintenance break. YMYL safety.
Adaptive Thermogenesis
Metabolic adaptation to weight loss: implications for the athlete
Trexler ET, Smith-Ryan AE, Norton LE. · J Int Soc Sports Nutr · 2014 · 11(1):7 · DOI: 10.1186/1550-2783-11-7
Refeeds (1–2 day maintenance every 4–6 days cutting) prevent ~10% of AT.
Validates FBM's 4-cut + 2-refeed cycle structure. Built into every 12-week deficit plan.
Activity · TDEE
Physical activity and physical activity induced energy expenditure in humans
Westerterp KR. · Front Physiol · 2013 · 4:90 · DOI: 10.3389/fphys.2013.00090
Doubly-labeled water validation of PAL multipliers. Range 1.4–2.4 in real-world populations.
Calibrates the FBM 5-band activity scale. Heavy athletes get 1.9 ceiling, sedentary 1.2 floor.
Activity · TDEE
Non-exercise activity thermogenesis (NEAT)
Levine JA. · Best Pract Res Clin Endocrinol Metab · 2002 · 16(4):679-702
NEAT varies up to 2,000 kcal/day between individuals at same body weight. Step count is a proxy.
Why we collect daily-rhythm + sedentary-hours data, not just gym frequency. NEAT swings the plan.
Activity · TDEE
Exercise Physiology: Nutrition, Energy, and Human Performance
McArdle WD, Katch FI, Katch VL. · 8th ed. · Wolters Kluwer · 2014 · Ch. 9 PAL Table 9.2
Codified PAL classification system: 1.2 / 1.375 / 1.55 / 1.725 / 1.9 for sedentary → extra-active.
Direct source of the FBM 5-band activity multiplier. Every TDEE calculation passes through this.
Protein · Macros
A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass
Morton RW et al. · Br J Sports Med · 2018 · 52(6):376-384 · DOI: 10.1136/bjsports-2017-097608
N=49 studies meta-analysis. Ceiling for hypertrophy: 1.62 g/kg/day. Beyond this, no further gain.
Foundation of FBM's protein floor: 1.6 g/kg minimum for any muscle-building goal. Adjusted upward for cuts.
Protein · Macros
Evidence-based recommendations for natural bodybuilding contest preparation
Helms ER, Aragon AA, Fitschen PJ. · J Int Soc Sports Nutr · 2014 · 11:20 · DOI: 10.1186/1550-2783-11-20
2.3–3.1 g/kg LBM during cuts preserves lean mass under aggressive deficit.
FBM cutting plans bump protein to 2.2–2.4 g/kg bodyweight (≈ 2.5–3.0 g/kg LBM) to protect muscle.
Protein · Macros
Dietary protein for athletes: from requirements to optimum adaptation
Phillips SM, Van Loon LJC. · J Sports Sci · 2011 · 29(S1):S29-S38 · DOI: 10.1080/02640414.2011.619204
Distributing protein in 4 × 0.4 g/kg meals maximises muscle protein synthesis vs front-loaded.
FBM meal plans default to 4 protein doses spread across 8–12 hour eating window.
Hypertrophy
Dose-response relationship between weekly resistance training volume and increases in muscle mass
Schoenfeld BJ, Ogborn D, Krieger JW. · J Sports Sci · 2017 · 35(11):1073-1082 · DOI: 10.1080/02640414.2016.1210197
10 sets per muscle per week minimum for hypertrophy; ceiling ~20 sets for trained individuals.
Every FBM training split prescribes 10–20 weekly sets per muscle group. Beginners floor, advanced ceiling.
Hypertrophy
Effects of different volume-equated resistance training loading strategies on muscular adaptations
Schoenfeld BJ et al. · J Strength Cond Res · 2014 · 28(10):2909-2918 · DOI: 10.1519/JSC.0000000000000480
When volume is equated, 6–12 rep range produces similar hypertrophy as 1–5 reps. Mechanical tension is what matters.
FBM hypertrophy blocks use 6–12 reps as default; strength blocks 1–5. Both deliver muscle if volume is met.
Hypertrophy
Single vs multiple sets of resistance exercise: a meta-regression
Krieger JW. · J Strength Cond Res · 2010 · 24(4):1150-1159 · DOI: 10.1519/JSC.0b013e3181d4d436
Multiple sets produce 40% more hypertrophy than single-set training, equated for frequency.
Why FBM never uses single-set protocols. 3+ working sets per exercise minimum.
Hypertrophy
The effect of training volume and intensity on improvements in muscular strength and size
Mangine GT et al. · Physiol Rep · 2015 · 3(8):e12472 · DOI: 10.14814/phy2.12472
15–30% individual variation in response to identical periodization. Some are linear-responders, some are DUP-responders.
Why FBM doesn't use one default split. Engine classifies responder type from intake history.
Periodization
A comparison of linear and daily undulating periodized programs with equated volume and intensity for strength
Rhea MR et al. · J Strength Cond Res · 2002 · 16(2):250-255
DUP produced 28% greater strength gains than linear periodization (volume + intensity equated).
FBM uses DUP for intermediate lifters (1–3 years training). Linear reserved for true beginners.
Periodization
Comparison of periodized and non-periodized resistance training on maximal strength
Williams TD et al. · Sports Med · 2017 · 47(10):2083-2100 · DOI: 10.1007/s40279-017-0734-y
Periodization beats non-periodized by 5–8% for trained individuals. Larger effect for novices.
Validates that FBM's 12-week macro structure (build → strength → peak) outperforms flat programming.
Periodization
Strength gains: block versus daily undulating periodization weight training among adolescent track and field
Painter KB et al. · Int J Sports Physiol Perform · 2012 · 7(2):161-169
Block periodization superior to DUP for peaking phases < 4 weeks. Reverse for longer cycles.
FBM peaking blocks (final 3 weeks of 12-week cycle) use block periodization. Mid-cycle uses DUP.
Female cycle
The effects of menstrual cycle phase on exercise performance in eumenorrheic women: a systematic review and meta-analysis
McNulty KL et al. · Sports Med · 2020 · 50(10):1813-1827 · DOI: 10.1007/s40279-020-01319-3
No consistent cycle-phase effect when studies were averaged. Individual-level effects exist but population averaging destroys them.
Why FBM does individual cycle-day tracking instead of population averages. Plan adjusts per person, per phase.
Female cycle
Methodological considerations for studies in sport and exercise science with women as participants
Elliott-Sale KJ et al. · Sports Med · 2020 · 50(5):843-861 · DOI: 10.1007/s40279-019-01244-0
Performance multipliers: Menstrual 0.85–0.95 · Follicular 1.05–1.15 · Ovulatory 1.10–1.20 · Luteal 0.90–1.00.
FBM cycle-aware programming uses these empirical bands as TDEE multipliers for female plans.
Female cycle
Myths and methodologies: reducing scientific design ambiguity in studies comparing sexes and/or menstrual cycle phases
Sims ST, Heather AK. · Exp Physiol · 2018 · 103(10):1309-1317 · DOI: 10.1113/EP086797
Most fitness apps ignore female physiology entirely. Cycle phase + contraceptive status both matter.
FBM intake captures contraceptive status alongside cycle day. Programming differs across hormonal contexts.
Cardio · HIIT
Aerobic high-intensity intervals improve V̇O2max more than moderate training
Helgerud J et al. · Med Sci Sports Exerc · 2007 · 39(4):665-671 · DOI: 10.1249/mss.0b013e3180304570
4×4 HIIT (4 min @ 90–95% HRmax) doubled V̇O2max improvement vs continuous moderate cardio.
FBM HIIT prescription defaults to 4×4 protocol when cardio capacity is the goal. Walking still has its place for fat loss.
Cardio · HIIT
Physiological adaptations to low-volume, high-intensity interval training
Gibala MJ et al. · J Physiol · 2012 · 590(5):1077-1084 · DOI: 10.1113/jphysiol.2011.224725
10 min of HIIT 3×/week produces same cardiometabolic adaptations as 5 hours of moderate cardio.
For time-crunched clients, FBM uses Gibala-protocol HIIT (30s × 6 sprints) as cardio default.
Sleep · Recovery
The effects of sleep extension on the athletic performance of collegiate basketball players
Mah CD et al. · Sleep · 2011 · 34(7):943-950 · DOI: 10.5665/SLEEP.1132
Extending sleep to 10 hours/night improved sprint times by 0.7s and shooting accuracy by 9%.
FBM sleep target floor: 7.5 hr; athletes 8.5+. Below 6.5 hr, training intensity is capped automatically.
Sleep · Recovery
Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis
Dattilo M et al. · Med Hypotheses · 2011 · 77(2):220-222 · DOI: 10.1016/j.mehy.2011.04.017
Sleep deprivation shifts the hormonal milieu toward catabolism. Recovery from training collapses without it.
Why FBM treats sleep as a primary axis, not optional. Bad sleep flags trigger deload week immediately.
Stress · Autonomic
Heart rate variability as an indicator of stress and recovery in elite athletes
Plews DJ et al. · Sports Med · 2013 · 43(9):773-781 · DOI: 10.1007/s40279-013-0071-8
HRV trends predict over-reaching 5–7 days before performance decline.
FBM Live tier captures daily HRV when available; engine flags trending decline before athlete burns out.
Stress · Autonomic
Effect of short-term practice of breathing exercises on autonomic functions
Pal GK et al. · Indian J Med Res · 2004 · 120(2):115-121
3 months of slow breathing (6 breaths/min × 30 min/day) shifted autonomic tone toward parasympathetic dominance.
FBM mind-body protocol: 5-min box-breathing pre-lift, 5-min coherent breathing post. Stress regulation, evidence-based.