PJ Glassey has spent almost 40 years testing what actually works in strength training, and it led him somewhere weird: racing up skyscraper stairwells. In this episode, the founder of XGYM breaks down fast twitch vs. slow twitch muscle fibers, the exact exercise protocol he used to increase a triathlete's stride power, why tower running might be the best cross-training a runner can do, and how to tell a legit study from a bogus one. We cover: • PJ's path from teenage bodybuilder to founder of XGYM's time-under-tension training method • How to actually evaluate a scientific study — and how to use AI to fact-check one • Fast twitch vs. slow twitch muscle fibers, explained for runners • The suspension lunge protocol PJ used to increase a triathlete's stride power • Tower running: what it is, why it's low-impact, and how it builds hill-running strength • Ways to replicate tower-running training without a stairwell (Jacob's ladder, stairmaster technique, versa climber) • Anti-aging: why quad strength predicts your mortality better than grip strength • Red light therapy: what's real, what's marketing, and how to vet a device Note: PJ shares a personal VO2 max result from his own training log. It's a compelling anecdote, not a controlled study — worth keeping in mind as you listen. Connect with XGYM Timestamps00:00 Welcome & guest intro 00:38 How PJ got into fitness (skinny kid → bodybuilder → trainer) 07:58 Why he founded XGYM in 1998 (less time, less injury, less bulk) 11:21 How to evaluate a scientific study (and use AI to fact-check it) 21:06 Pivoting to running: what PJ has learned training runners 23:16 Stride frequency vs. stride length — the only two ways to get faster 24:20 The suspension lunge protocol (built a triathlete's stride power) 31:24 Fast twitch vs. slow twitch, explained simply 38:22 What is tower running, and why is it the best sport you've never heard of 41:07 Why tower running builds hill strength without the joint damage 47:53 PJ's VO2 max results from anaerobic training (his own data — not a study) 49:24 Suffering as a trainable skill (“best at suffering,” not best-conditioned) 51:50 Replicating tower-run training: Jacob's ladder, stairmaster, versa climber 55:47 Tower running stories: stairwell hacking, team records, the community 1:01:12 Anti-aging: comfort zone expansion, quad strength vs. grip strength 1:04:00 Practical steps for people starting from pain or sedentary life 1:05:12 Red light therapy: what matters, what's marketing 1:09:34 Where to find XGYM, the brain type test 1:11:20 Wrap up Follow on apple, youtube and Instagram @evan_blakeney on Instagram Links: Buzzsprout Apple Podcasts Spotify YouTube Instagram Facebook Guest — XGYM Until Next Time: Just Keep Running