The Learn Hub
What does the
evidence actually say?
Research-backed articles across peptides, GLP-1, recovery, and longevity — written to answer one question at a time, with sources and confidence levels.
Peptides
Mechanisms, research, benefits, limitations, and emerging applications.
110 articles →GLP-1 & Metabolic
Metabolic health, appetite regulation, and modern weight management.
122 articles →Recovery
Sleep, nutrition, recovery strategies, and emerging therapies.
84 articles →Longevity
Biomarkers, healthy aging, preventative health, and lifespan research.
103 articles →Latest research
419 articles published
Bone Density and Healthy Aging
Why skeletal health quietly determines independence in later decades, and what the trials say actually helps — loading and nutrition.
Read →Essential Fat: How Low Is Too Low?
Essential body fat is the minimum the body needs to function: about 3% for men and 12% for women. What happens when you drop below it, and why.
Read →How to Lower Body Fat Without Losing Muscle
How to lose fat, not muscle: the evidence on modest deficits, high protein, and resistance training that lets you drop body fat while holding lean mass.
Read →Navy vs DEXA vs Calipers vs BIA: Accuracy
The most accurate body fat measurement, compared: how DEXA, calipers, BIA scales, and the Navy tape method stack up on accuracy, cost, and consistency.
Read →Healthy Body Fat Percentage by Age and Sex
What's a healthy body fat percentage by age and sex? Category ranges for men and women, why the healthy range widens with age, and how to read your number.
Read →Testing Strength After 50: 1RM for Older Lifters
Strength testing for older adults: how to assess 1RM safely after 50, why familiarization and submaximal estimates matter, and alternatives to maxing.
Read →How to Test Your 1RM Safely (Without Maxing Out)
How to test your 1RM safely: a step-by-step warm-up and attempt protocol, spotter and readiness rules, plus when to estimate your one-rep max instead.
Read →RPE vs Percentage-Based Training: Which Wins?
RPE vs percentage-based training: what autoregulation research shows about strength gains, day-to-day readiness, and which method fits your lifting.
Read →Strength Standards: Is Your Bench, Squat, Deadlift Good?
Strength standards by bodyweight: how good is your bench, squat, and deadlift? Compare your lifts to untrained-to-elite benchmarks as bodyweight multiples.
Read →Training Percentages: How to Program Off Your 1RM
A practical 1RM percentage chart: how to turn your one-rep max into training loads for strength, hypertrophy, and endurance, with rep targets per zone.
Read →How Accurate Are 1RM Formulas? Epley vs Brzycki
How accurate are 1RM formulas? Compare Epley vs Brzycki, see where rep-based estimates drift, and why staying under 10 reps gives the best 1RM accuracy.
Read →VO2 Max After 50: Can You Still Improve It?
Can you improve VO2 max after 50? Yes. Much age-related decline is driven by inactivity, and structured aerobic training still improves fitness at any age.
Read →VO2 Max vs Zone 2: How They Fit Together
VO2 max vs zone 2: how a low-intensity aerobic base and high-intensity intervals fit together, and why polarized training beats doing either alone.
Read →How Accurate Is Your Watch's VO2 Max?
How accurate is your Garmin or Apple Watch VO2 max? Validation studies show wearables underestimate it, with error growing as your fitness rises.
Read →Estimating VO2 Max From Resting Heart Rate
How to estimate VO2 max from resting heart rate using the Heart Rate Ratio Method: the formula, how accurate it is, and who it works best for.
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