Dr. Sarah Okafor

About

Dr. Sarah Okafor holds a PhD in Exercise Physiology from the University of Texas and spent five years running clinical trials on metabolic adaptation before becoming a full-time fitness writer. She bridges the gap between peer-reviewed research and the gym floor — evidence-first but deeply practical. She trains herself (powerlifting and zone 2 cardio) and has zero patience for marketing-driven fitness claims. Every recommendation she publishes is backed by specific studies, sample sizes, and effect sizes.

Areas of expertise

• TDEE & energy expenditure
• body composition
• heart rate training zones
• macronutrient optimization
• progressive overload
• recovery science
• metabolic adaptation

Articles by Dr. Sarah Okafor (29)

• Creatine Timing — Does It Actually Matter? (Evidence Review)
  2026-04-20 · Nutrition

  Does creatine timing matter? The Antonio 2013 pre vs post study, the Kreider ISSN position stand, and what the meta-analyses say about dose timing, co-ingestion, and rest days.

• Sleep and Muscle Growth — What the 2023 RCT Evidence Actually Shows
  2026-04-20 · Recovery

  Sleep and muscle growth: the Saner 2023 RCT on sleep restriction and muscle protein synthesis, the Dattilo 2020 review, and how much sleep you need for hypertrophy.

• Protein Per Meal — Is There Really a 30g Cap? (2023 Evidence Review)
  2026-04-20 · Nutrition

  The 30g protein cap per meal myth, the Trommelen 2023 100g bolus study, and the Schoenfeld-Aragon optimal-distribution data. What the evidence actually says.

• Fasted Cardio vs Fed — What the 2024 Meta-Analysis Says
  2026-04-20 · Fitness

  Fasted cardio vs fed: the 2024 meta-analysis of 9 RCTs, the Schoenfeld 2014 body comp study, and the within-session substrate data. Does fasted cardio actually burn more fat?

• HRV Training — Signal vs Noise (Evidence Review)
  2026-04-20 · Fitness

  Heart rate variability for training: what HRV actually measures, whether HRV-guided training beats fixed programs, and how to tell signal from noise in your wearable data.

• Progressive Overload for Beginners vs Intermediates (Evidence Review)
  2026-04-20 · Training

  Progressive overload: linear novice gains vs intermediate periodization. The Grgic periodization meta, Schoenfeld volume dose-response, and the double progression model.

• Carb Cycling — Evidence or Placebo? (2026 Review)
  2026-04-20 · Nutrition

  Does carb cycling actually work? The Davoodi RCT, Hall 2017 energy balance modeling, and what the evidence says about training-day vs rest-day carb splits.

• Warm-Up Sets — How Many Do You Actually Need?
  2026-04-20 · Training

  Warm-up sets: how many, which progression, and why static stretching hurts your lifts. The Behm 2011 dynamic warm-up review and practical progression schemes.

• Rest Between Sets — Why 2-3 Minutes Wins (RCT Evidence)
  2026-04-20 · Training

  How long to rest between sets: the Schoenfeld 2016 RCT, phosphocreatine recovery kinetics, and why 1-minute rest costs you real strength and muscle gains.

• RPE vs RIR — How Lifters Actually Calibrate Effort (Evidence Review)
  2026-04-20 · Training

  RPE vs RIR explained: the Tuchscherer chart, Zourdos accuracy data, and how to use autoregulation in hypertrophy and strength programs. With a calibration protocol.

• Walking After Meals — The 2-Hour Glucose Window (Evidence Review)
  2026-04-20 · Health Metrics

  A 2-minute post-meal walk measurably lowers the glucose spike. The Buffey 2022 meta-analysis, the GLUT4 mechanism, and exactly when, how long, and how fast to walk.

• Cold Plunge vs Sauna for Recovery — What the Research Actually Shows
  2026-04-20 · Recovery

  Cold plunge vs sauna for recovery: the Roberts hypertrophy-blunting study, the Laukkanen mortality data, and exactly when and how long to use each.

• VO2 Max Targets by Age — ACSM 2024 Norms (Evidence Review)
  2026-04-20 · Fitness

  VO2 max targets by age and sex using ACSM 2024 reference standards. The FRIEND registry norms, the Mandsager mortality data, and a training plan to hit the next percentile.

• Deload Weeks for Natural Lifters — When, How, and Why (Evidence Review)
  2026-04-20 · Training

  Deload weeks for natural lifters: the 4-6 week cadence, the 50% volume reduction protocol, and the Kreher/Meeusen overreaching research. Plus exact warning signs.

• Zone 2 Cardio Heart Rate — How to Find Yours (and Why It Works)
  2026-04-18 · Fitness

  Your exact Zone 2 heart rate range using the Tanaka formula and MAF method, the lactate science behind it, and a 4-week starter plan backed by peer-reviewed research.

• Lean Body Mass vs Body Fat % — Which to Track for Real Progress
  2026-04-18 · Health Metrics

  Lean body mass or body fat percentage — which actually shows progress? What each metric means, measurement accuracy of each method, and which to weight more during cuts and bulks.

• Macros for Cutting vs Bulking — 2026 Evidence Review
  2026-04-18 · Nutrition

  Evidence-based macro splits for cutting and bulking in 2026 — protein, carbs, fat ranges with citations to Helms, Morton, and Aragon/Schoenfeld. Plus GLP-1 era adjustments.

• How Many Calories to Lose 1 lb Per Week — The Math and the Reality
  2026-04-18 · Calculators

  The 500 kcal/day rule, the Hall dynamic model from The Lancet, and the real-world adjustments needed to sustain 1 lb/week over a 12-week cut.

• Creatine Dosing — Loading Phase vs Maintenance (What the Meta-Analyses Say)
  2026-04-18 · Nutrition

  What the ISSN 2017 position stand, the Devries-Phillips meta-analysis, and the Hultman saturation data actually say about loading vs maintenance-only dosing. Exact protocols included.

• TDEE Calculator Accuracy: How Well Do Online Tools Actually Work?
  2026-03-30 · Calculators

  We analyzed the real accuracy gap in TDEE calculators — from formula error (±140 calories) to activity multiplier variance (±300 calories) to NEAT variability (up to 2,000 calories between individuals). Here's how far off your estimate might be and how to calibrate it.

• BMI Calculator: What Your Number Actually Means (And What Doctors Say Instead)
  2026-03-30 · Health Metrics

  Your BMI categorizes your weight — but what does the number actually tell you about your health? Evidence-based breakdown of BMI accuracy, where it fails, and what physicians use instead.

• TDEE Calculator: The Science Behind How Many Calories You Actually Need
  2026-03-30 · Calculators

  The Mifflin-St Jeor formula is accurate for 82% of normal-weight adults — but drops to 67% accuracy for people with obesity and 71% for trained athletes.

• How Many Calories Does Walking Really Burn? The Science Behind Every Step
  2026-03-28 · Fitness

  Walking burns more calories than most people think — but the exact number depends on speed, weight, and terrain. Here is the real math using MET values from exercise science.

• The 5 Heart Rate Zones That Make or Break Your Workout
  2026-03-28 · Fitness

  Training in the wrong heart rate zone wastes effort. Learn the 5 zones, when to use each, and how to calculate your personal ranges using the Tanaka and Karvonen formulas.

• Body Recomp: How to Build Muscle and Lose Fat at the Same Time
  2026-03-28 · Fitness

  Body recomposition is real — but only under the right conditions. Learn the science, the macro split, and who it actually works for.

• We Compared 5 TDEE Formulas Against 1,090 Lab Measurements — Here's Which One Works
  2026-03-27 · Calculators

  Peer-reviewed accuracy data for Mifflin-St Jeor, Harris-Benedict, WHO, Cunningham, and Katch-McArdle. Segmented by BMI, sex, and body type — plus why GLP-1 drugs break standard TDEE formulas.

• How to Calculate Your TDEE: The Complete Guide
  2026-03-27 · Calculators

  Your Total Daily Energy Expenditure determines how many calories you burn per day. Learn the Mifflin-St Jeor and Harris-Benedict formulas, activity multipliers, and how to use TDEE for weight loss or muscle gain.

• BMI vs Body Fat Percentage: Which Matters More?
  2026-03-27 · Health Metrics

  BMI is simple but misleading for many people. Body fat percentage gives a more accurate picture of health. Here is when each metric is useful and when it fails.

• Macro Calculator Guide: Protein, Carbs, and Fat Explained
  2026-03-27 · Nutrition

  Counting macros beats counting calories for body composition goals. Learn how to calculate your ideal protein, carb, and fat ratios for cutting, bulking, or maintenance.