Hot Topics in the Science of Running

Hot Topics in the Science of Running Mike Young, PhD HPC - Athletic Lab Cary, North Carolina

EN S HA NIC N A CI CH N G ME EC AL O TIM N O OP M Y AC IES ALL SS F BAFIT NE RE FO OT RU NN IN G

FITNESS FALLACIES Lotta Bull & Hugh Lyon Sack

MA ’AM TS , E FAC ST THJU

L AC T IC

Fa tigue Cramping Muscle Pulls Soreness W orld Hu nger

GLYCOLYTIC FATIGUE FA LS ELY• Lacticacid is blamed for pain and fatigue from anaerobic glycolytic training• Fatigueis not fully understood but may be caused by peripheral issues at muscular level, feedback inhibition of central nervous system, or other causes

At normal pH, lacticacid 98% dissociates to lactate and H+

MYTH BUSTED• Lactateinfusion trials produce no detrimental effects on perceived effort or pain - Miller (2002, 2005)• No evidence linking lactate to discomfort, injury, fatigue, etc

CorrelationD O E S N OT i m p l yCausation

The REAL Culprit?

icatio n?Appl

FlexibilRotten Core ity Myth s

reduce soreness tching doesn’t ou sore•Stre etching can MAKE y•O ver str

Stretching Does Not Decrease Injury

•Stretching makes you weaker (a c ute)

makes you sl ower (acute)•Stretching stretching = m ore slower•More

le? xi bFle o To

Stewart & Burden, 2004DANGER OF HYPERMOBILITY

DYNAMIC FLEXIBILITY

HURDLE MOBILITY

h: Mind- numbingMyt ps of “a bs” are re runnersbenef icial for Reality: R unning & loaded exe rcises are least as b at eneficial

Core Strength• Refers to functional capacity & positioning of core of body• Use static & dynamic movements• Whole body movements requiring mid- line stabilization are beneﬁcial

Activity of trunk muscles during squats and pulls from the floor (dead lifts) is greater or equal to that produced with many common stability ball exercises.Journal of Strength & Conditioning Research, Volume 22, Issue 1, Pages 95-102, 2008.Trunk Muscle Activity During Stability Ball and Free Weight Exercises: Nuzzo, McCaulley, Cormie, Cavill, and McBride

Core Training

tim izingOp e ch an ics?M

General Goals of RunningMinimize brakingforcesEffective groundcontact

Minimize Braking ForcesDecreases horizontalvelocityCaused by excessive steplength and positive foot andleg speed at ground contact

EFFECTIVE GROUNDCONTACT POSITION

Co ach w it ho utCo achi ng!

Self-Optimiz t a ion?

Research suggests that the human body may self-optimize movement

BUT only with practice!

Mirroring?

PosturePosture Trunk Erect Head Level Hips Tall

Postural Test!

Developmental COncerns

Forefoot vs Heel Strike?

Factors to Consider A ge Sp ee d Per forma nceDev Effic elo iency pm e nt

What should Ilook for in running?

Ground ContactUpright postureMinimize horizontaldistance between footand hipsLegs together

Early Stance Phase Upright posture Appropriate step-over height

Late Stance PhaseUpright postureAppropriate kneeheightSwing leg unfolds

Toe OffProjection of non-support hipAppropriate kneeheightMinimal backsidemechanics

FlightAppropriate verticaldisplacementPreparation forground contact

Technical PointsFix postureWatch ground contact positionRun tall

RUNNING ECONOMY

FACTORS AFFECTING RUNNING ECONOMY• Biomechanics • Race • Vertical motion while running • Weight of clothing and shoes • Technique and type of activity • Fatigue• Fitness and training • Environmental conditions• Individual factors • Neuromuscular efﬁciency • Age • Gender

NEUROMUSCULAR EFFICIENCY• Ability of neuromuscular system to allow prime movers, synergists, stabilizers, and neutralizers to work together synergistically as an integrated functional system

Running Economy

MECHANISMS OF BENEFIT• Running economy is a result of enhanced neuromuscular characteristics like improved muscle power development and more efﬁcient use of stored elastic energy• Resistance training using heavier loads or explosive movements improves muscle power and enhances the ability to store and use elastic energy

•2.9% Impr•4.6% Impr oved Per formanc oved Eco e nomy

Evidence Supporting Evidence Refuting Resistance Training Resistance Training• K Stkren, J Helgerud, E Stka, and J Hoff. Maximal Strength Training Improves Running Economy in Distance Runners. MSSE 2008• G Millet, B Jaouen, F Borrani, and R Candau. Effects of concurrent endurance and strength training on running economy and VO2 kinetics. MSSE 2002.• J Esteve-Lanao, M Rhea, S Fleck, and A Lucia. Running Speciﬁc Periodized Strength Training Attenuates Loss of Stride Length during intense Endurance Running. JSCR 2008.• And MUCH MORE

Methods• 1-3x/ week• Short but intense workouts• 15-30 minutes per session is sufﬁcient• High load / low rep or explosive• Train the entire body• Use appropriate rest intervals

TRAINING HOLISTICALLY• Muscles don’t act in isolation• Train movements not muscles• Address asymmetries and imbalances

EXERCISE SELECTION• Multi-joint exercises through complete ranges of motion• ~50 / 50 split upper / lower body

STRENGTH

POWER DEVELOPMENTExercise Absolute Power (Watts) 100kg Male 75kg FemaleBench Press 300Back Squat 1100Deadlift 1100Snatch 3000 1750Snatch 2nd Pull 5500 2900Clean 2950 1750Clean 2nd Pull 5500 2650Jerk 5400 2600 *Total pull: Lift-off until maximal vertical velocity **2nd pull: Transition until maximal vertical barbell velocity

EXERCISE SELECTION - POWER

Heavy-Low Rep vs. Light-High Rep

Barefoot Running?

The Argument For Au Naturale

20 years later Zola Budd achieved similar levels of success running barefoot

B UT .. ..

Usecommon sense!

Consider the surface Individual mechanicsProceed with cautionAppropriate footwear

If you like it, thats grea t, But there is no evidence wh atsoever that b arefoot running cau ses less injury.Dr. Benno Nigg

Go back to c ommon sense,if you have a shoe that has never give n you injuries, keep it.Dr. Benno Nigg

Closing Thoughts me n othing Assu Question every thing “Common” sense? Science is fu ndamental

THANKSMIKE@ATHLETICLAB.COMTWITTER.COM/MIKEYOUNGATHLETICLAB.COMELITETRACK.COMHPCSPORT.COM

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Hot Topics in the Science of Running

by Mike Young on Feb 25, 2011

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Hot Topics in the Science of Running — Presentation Transcript