Posterior chain timing changes across the sprint cycle. This review...

@Fred__Duncan
Fred Duncan@Fred__Duncan
76 views May 14, 2026 ~1 min read
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Posterior chain timing changes across the sprint cycle.

This review shows the biceps femoris reaching very high activation around late swing, while the glute max peaks closer to early stance.
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So the hamstrings aren’t just “pushing you down the track.” They are preparing the limb for contact, helping control the swing leg, and setting up positions.

As speed rises, the timing demand gets tighter. The athlete has less time to organize the limb, maintain posture, and
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hit efficient positions.

You need the preparation block that builds the tissues and movement qualities, then you need the speed work that teaches the athlete how to express it.

GPP Reloaded gives you the foundation.

Speed Kills takes that foundation into acceleration,
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max velocity, plyometrics, resisted sprints, and full speed development.

Both are available now

fredduncantraining.com/product/gpp-re…
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People love to jump to conclusions based on tiny bits of information.

Gout Gout is 18 years old and Noah Lyles is an Olympic gold medalist, so let’s keep it in perspective.

Watching one block start in training and declaring a diagnosis is lazy analysis.

Yes, the start can
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