morin emg 2015_slideshare.pptx

MUSCULAR POWER AND PERFORMANCE IN MASTERS ATHLETES

APPLICATION TO SPRINT RUNNING

@jb_morin

Pr. J-B Morin Université de Nice Sophia Antipolis Laboratoire Motricité Humaine, Education, Sport, Santé

[email protected]

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unice.frstaps.

PERFORMANCE EN SPRINT CHEZ LES ATHLÈTES MASTER – JB MORIN

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MUSCULAR POWER, EXPLOSIVENESS AND SPRINT


Membre deMUSCULAR POWER, EXPLOSIVE STRENGTH AND SPRINT

Power =

Force x elocity =

Work / Time

Pmax after ≈2s

15 to 30 W/kg

Explosiveness =

Rate of force production

Start….

Each step…


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SPRINT PERFORMANCE AND AGING


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-‐0.73% /yr

-‐0.89% /yr

-‐1.02% /yr

-‐0.82% /yr

Rittweger, Proc Roy Soc B, 2009


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Gatlin (USA) 22yrs: 9.85 s 33yrs: 9.74 s

Powell (USA) 22yrs: 9.87 s 33yrs: 9.81 s

Collins (St-‐K-‐N) PB at 38yrs: 9.96 s 2003 (27yrs: 9.99 s) 2015 (39yrs: 9.98 s)


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KNOWLEDGE…

TRAINING / PERFORMANCE HEALTH / WELL-‐BEING

Hidekichi Miyazaki WR 105yrs: 42.22 s


Membre deFORCE – VELOCITY – EXPLOSIVENESS….

Lindle, J Appl Physiol, 1997 Vanderwoort, Muscle Nerve, 2002



Doherty, J Appl Physiol, 2003 Porter, Scand J Med Sci Sport, 1995



Sipila, Eur J Appl Physiol, 1991



Korhonen, J Appl Physiol, 2006



More « specific » tests?

Edwen, Scand J Med Sci Sport, 2014


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OK WHAT ABOUT SPRINT MECHANICS?

Membre deSPRINT MECHANICS IN MASTER ATHLETES….

Korhonen, Med Sci Sport Exerc, 2003 200 Hz

FREQUENCY = 1/(CONTACT TIME + FLIGHT TIME)

≈4 HZ

Membre deSPRINT MECHANICS IN MASTER ATHLETES….

Korhonen, Med Sci Sport Exerc, 2003 RUNNING SPEED = STEP LENGTH X STEP FREQUENCY

200 Hz

FREQUENCY = 1/(CONTACT TIME + FLIGHT TIME)

≈4 HZ


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Leg extension, jumps or temporal variables, no SPRINTING Force and Power outputs


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1 STUDY….

Korhonen, Med Sci Sport Exerc, 2006


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HOW?

Only 2 (im)possibilities L

SPRINT INSTRUMENTED TREADMILL St-Etienne, France Doha, Qatar Houston, TX

FORCE PLATES INSEP, Paris, France

POWER, FORCE, VELOCITY MEASUREMENTS DURING SPRINTING


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Rabita, Scand J Med Sci Sport 2015

2011 – 2015

Sprint Instrumented treadmill Track-‐Embedded Force Plates Elite Athletes

Horizontal GRF is paramount for acceleration Vertical GRF is paramount for top speed HZT Force at high speed higher in top athletes Hip extensors play a key role

Med Sci Sport Exerc 2011 Eur J Appl Physiol 2012 Scand J Med Sci Sport 2015 J Biomech 2015 Frontiers Physiol 2015

DETERMINANTS OF SPRINT RUNNING PERFORMANCE

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FIELD MEASUREMENTS?

Only 2 (im)possibilities L

SPRINT INSTRUMENTED TREADMILL St-Etienne, France Doha, Qatar

FORCE PLATES INSEP, Paris, France

2015

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1927

Archibald V. HILL

1950’s

Franklin Henry

Modern Devices

v(t) = vmax.(1-e(-t/τ))

vmax

di Prampero et al., J Exp biol, 2005 Furusawa et al., 1927

Henry, 1954 Volkov & Lapin, 1979

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a(t) = (vmax/τ).e(-t/τ))

Fh(t) = m.a(t) + Fair Estimated from speed, mass and height

Ph(t) = Fh (t) . v(t)

v(t)

Ph(t) Fh(t)

Linear F-V relationship Polynomial 2 P-V relationship Validity ??

F0

V0

Pmax


A simple Xield method

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v(t) = vmax.(1-e(-t/τ))

Comparison with force plates

Validity, Reproductibility J

A simple Xield method

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Coming soon: simpler devices !

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P. Jimenez-Reyes, UCAM, Spain

iPhone6 app “MySprint”, 240 fps

E-J Marey, 1882

Fusil Chronophotographique, 24 fps

Pierre Samozino, PhD University of Savoy

FORCE-‐VELOCITY-‐POWER outputs of Usain Bolt’s World Record Running Speed (m/s)

Distance (m)

S(t) = Smax 1− e−t/τ( )

Field Measurements In competition conditions

Computing

Modeled Speed-‐time curve

Computed Net Horizontal Force output

Max Power Output of 30 W/kg reached after about 1 s…

Power = Force x Speed… Specihic, Field Sprint Force-‐Velocity-‐Power prohile

Jean-‐Benoit Morin, PhD University of Nice

“F0”

“V0”

Pmax

Vopt

F0 and V0 are the theoretical maximal outputs of the system Vopt is the speed at which Pmax is produced The magnitude of the slope (F0/V0) describes the Force-‐Velocity prohile of the athlete


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WHAT ABOUT MASTERS?


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OCTOBER 3-‐4, 2015 NICE

THANKS: Athletes, Organizers, Julien, Mehdi, Emilien, Guillaume

39 athletes 39 to 96 years old Sprint mechanics with aging? Force, Power, Velocity, Effectiveness Comparison to young elite data

Slawinski, Scand J Med Sci Sport, in press


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RESULTS…IN PROGRESS

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Merci !

morin emg 2015_slideshare.pptx

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