Most athletes are stuck because they're making one (or all) of...

1.) Mimicking elites - You can't copy someone else's form if you don't have their hours of practice + match their biomotor profile. Mechanics are an expression of ability,
2.) Focusing on minutiae - These things (like "ankle stiffness) are byproducts of good form or developed abilities, not things you force/cue.
3.) Inconsistency - Speed is a skill. If you only sprint every few weeks, you'll never get faster.
If you can fix these, you'll actually start building real speed.
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