Today’s episode features JB Morin, who returns to the show after being guest #12, 3 years ago. JB is a world-leading researcher in the world of sprint biomechanics and forces, as well as resisted sprinting, force-velocity profiling and sprint injury factors. He is currently Full Professor at the Faculty of Sport Sciences of the University of Nice Sophia Antipolis (France). There he is a member of the Laboratory of Human Motor Function, Education Sport and Health. On our last podcast, JB went in depth into force-velocity profiling for sprinting, as well as the role of heavy sled sprint training and much more.

JB is currently working to bring more clarity to the puzzle of sprint enhancement and hamstring injury prevention. As research is quickly shedding more light on various factors in human performance, especially in the sprint sector, I was excited to bring JB back for another show.

On this episode, JB picks up where we left off, going over recent updates in sprint research and force velocity profiling. The main focus of this show is digging into sprint mechanics, fatigue, and hamstring injuries in sport. We’ll also get into ideas on correlation vs. causation in interpreting statistics and research, as well as recent ideas on the role of the foot and ankle in sprint performance.

Today’s episode is brought to you by SimpliFaster, supplier of high-end athletic development tools, such as the Freelap timing system, kBox, Sprint 1080, and more.



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Key Points

• What’s new in resisted sprint training research over the last few years
• Strength training in regards to the force velocity curve in sprinting
• Correlation versus causation with strength training and sprinting ability
• What are we seeing with sprint technique and hamstring injuries according to recent research
• Core strength/rotation and sprinting in regards to hamstring injury rates
• The roles of fatigue in hamstring injuries
• Recent research on the foot, ankle stiffness, injury and performance
• Clarification of the causation/correlation effects in jump tests and sprinting



 
JB Morin Quotes
“Sprinting is catching up with the velocity based training that is well known in the gym”

“When you sprint only once, then you cover the entire force velocity spectrum”

“There is not a lot of work published on how gym work influences sprinting force/velocity profile”

“Don’t interpret transfer of training from correlations that are cross-sectional (correlation does not equal causation)”

“If you train a couple of school kids and they improve their level of strength and you assess that at the gym, yes they will improve their sprint times, but at some point you are not dealing with school kids anymore”

“We have some very high level rugby players tested, and there is no correlation between vertical F0 (equivalent of their 1RM in half squat) and their F0 in sprinting… there is no correlation in these trained people”

“Jumping shouldn’t be the first information we collect if we are dealing with sprint people, it should be so obvious”

“It’s easier to measure jumping variables in sprinters rather than sprint, and for that single reason in my opinion, we explain some of the misconception (why so many people want to use jumping as a sprint assessment or predictor)”

“It is much easier to measure your hamstring strength, rather than exploring and measuring and detailing your sprint technique”

“I will name two (factors with sprint technique and hamstring injury) the first one is trunk lateral motion…. Future injured players in rugby tended to have more lateral trunk flexion in swing phase…. The core muscle activity (mainly trunk, glutes, superficial muscles) is clearly lower in soccer players who sustain a hamstring injury during the season when they sprint”

“One track research we have is around pelvic tilt angle, how your pelvis is tilted when you enter the swing phase of ...