Again with this heard coaches, people and athletes say this, that a strong core keeps your knee lift high. Any truth to this?
Also, isnt the “core” over rated?
considering that when you sprint your body is under 6 times gravity or so, the core is probably important.
High knee lift while sprinting is a myth. Just to let you know.
Can you please clarify in more detail, this has puzzled me for 2 years now.
please enlighten us
along with weight training and a healthy diet, all myths 
. of course its not a myth. when was the last time you saw asafa powell sprinting. his knees come up pretty high
Too much vertical is never a good thing. Neither is too much horizontal. This is sprinting 101.
Try running as fast as you can with high knees the whole time. LOL. Mind as well be doing plyos.
Optimal knee height is up to the point where the knee is farthest away from the torso (slightly below hip height). If you go higher then the knee is coming in towards the torso and, action/reaction, the support leg buckles as it then must also move towards the torso, reducing drive. If you go lower than that, you have insufficient time to accelerate the foot towards the ground.
Finally we get a opinion from someone who fully explains and knows what he’s saying to the full. Then again thats why we’re all here.
Those sprinters, such as Powell, who appear to run with much greater knee lift than others are, in my view, simply bringing the knee forward with greater force (coupled with great flexibility) which, in turn, results in greater lift.
Even in Powell’s case, however, one will notice that the degree of hip flexion he generates during max v is still well beneath that attained during his performance of high knees or A skips.
The lift, during the sprint, being a byproduct more than a volitional effort.
In contrast, drills such as A skips, high knees, etc allow that the athlete volitionally ‘lift’ the knees beyond the level of hip flexion that would be attained during a sprint.
Additionally, those athletes with less than sufficient hamstring flexibility will attain much less ‘knee lift’ when sprinting and the ‘buckling’ of the support leg that Charlie referred to will absolutely occur if the athlete is mistakenly coached to lift the knees while sprinting.