A new study mapped how power shifts as speed increases. At slower...
Fred Duncan@Fred__Duncan
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Nov 24, 2025
~1 min read
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A new study mapped how power shifts as speed increases. At slower velocities, the plantar flexors drive most of the work, but as speed rises, their role drops while the hip extensors and hamstrings take over.
Once you move past roughly 22 km/h, sprinting becomes a hip dominant
Once you move past roughly 22 km/h, sprinting becomes a hip dominant
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task. That’s why you need to develop the hips and hamstrings to handle the highest outputs at max velocity.
Speed Kills shows you exactly how to do that, how to target the right muscles at the right speeds, and how to program sprint training that actually transfers to
Speed Kills shows you exactly how to do that, how to target the right muscles at the right speeds, and how to program sprint training that actually transfers to
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Speed is about how you apply force.
Research continues to show that net horizontal force, especially in the first few steps, is one of the strongest predictors of acceleration performance (Morin et al., 2011, Cross et al., 2018).
You can lift heavy and still be slow if you’re
Research continues to show that net horizontal force, especially in the first few steps, is one of the strongest predictors of acceleration performance (Morin et al., 2011, Cross et al., 2018).
You can lift heavy and still be slow if you’re