Sports science, distilled.
Summaries and analysis of key research papers in sports science, velocity-based training, and performance measurement.
When Your Tennis Serve Speed Gun and IMU Disagree: Ball Speed vs. Racket Speed Explained
A racket IMU reading half your radar number isn't broken - it's measuring a different object. See the physics, two real studies, and how to read both.
When VBT Velocity Jumps After Caffeine: Reading It Right
A caffeine-driven bar speed jump isn't a strength gain. How to separate stimulant-driven VBT velocity spikes from a real 1RM improvement, with numbers.
Weight-Bearing Lunge Test: Ankle Dorsiflexion Norms and What Side-to-Side Asymmetry Actually Means
Knee-to-wall distance norms for the weight-bearing lunge test, plus the asymmetry cutoff (cm) research links to ankle sprain recurrence and reinjury risk.
Why Golf Clubhead Speed Numbers Differ on Mats vs. Grass: Reading Lie, Bounce, and Light Correctly
A 4 mph gap between the mat and the range usually isn't your swing decaying. It's bounce-turf interaction, contact point, and indoor light moving the number.
Why HRV Tanks After Alcohol, Not Overtraining: Reading the Real Cause of an Acute HRV Drop
Two beers can crash your HRV harder than a brutal squat session. Decision rules for separating alcohol, sleep, and caffeine noise from real training fatigue.
Why Sled Sprint Times Vary by Surface: A Friction Correction Standard
A 30% jump in sled resistance can hide in a surface change alone. Here is the friction math coaches use to correct sled loads between track, turf, and grass.
Why a Two-Load LV Profile Gives You the Wrong 1RM
A two-load velocity profile can be off by 10-20% on your 1RM when the loads sit too close together or bunch at one end. Here's why - and the fix.
Time of Day and Strength Performance: What the Research Shows
Force output can swing 5-10% across the day, and it's not random. Core temperature and training habit drive it. Here's what the studies actually measured.
Morning Priming Sessions Before Competition: Evidence Review
Two controlled studies test whether a morning priming session before competition raises afternoon power and readiness, plus the exact protocol.
EMS Training: Research on Electrical Muscle Stimulation Effectiveness
20-minute EMS training claims a full workout's worth of strength gain. Here is what Kemmler and Filipovic actually measured, and where the evidence stops
External Focus Cueing: Why Outward Attention Boosts Power
External focus cueing research: how directing attention outward — not at your own body — boosts force output, jump height, and movement accuracy.
Ischemic Preconditioning and Athletic Performance: Research Review
IPC's ergogenic effect on endurance output splits the literature roughly down the middle. Here is what the cuff protocols, effect sizes, and non-responder data.