Newton Neutral racers Do they really improve performance? Brendan Rickert

What are Newtons? Unique design feature called “Lugs” Actuator “ Land-Lever-Lift” mechanism1 Newton’s 3rd Law- For every action there is an equal and opposite reaction1

Background Shoes can play an impact in performance by maximizing energy return and minimizing energy loss2 Midsole materials can change performance2 Shoe characteristics can elicit a kinematic adaptation3

Background Continued Soft shoe materials lower oxygen demands4 Racing flats improve performance compared to trainers5

Shoe Condition WITH LUGS (WL) Newton Neutral Racers Weight = 9.0 ± 1.6 oz shaved off (8.4 ± 1.3 oz) WITHOUT LUGS (WOL) Newton Neutral Racers Weight = 8.4 ± 1.3 oz

Research Hypothesis It was hypothesized that the Newton Neutral Racer running shoe with forefoot lugs would improve running efficiency as compared to the same shoe without forefoot lugs.

Study Design Day 1 VO2Peak Testing Four Stages, two trials within each 6 min. each trial Day 2 5 min. rest One with Lugs, One without 60% of VO2Peak 1st Stage 70% of VO2Peak 2nd Stage 80% of VO2Peak 3rd Stage 90% of VO2Peak 4th Stage

Participants 12 elite male runners (23.6 ± 4.2 yo, 71.8 ± 6.9 ml/kg/min VO2 Peak)

Day 1 Testing VO2 Peak Test Any foot wear GXT Any foot wear Results used to determine speeds for Day 2 Testing 60, 70, 80, 90%

Day 2 Testing 4 Stages (60%, 70%, 80%, 90%) determined from initial VO2 Peak results Two trials within each stage, one with unchanged Newtons, one with shaved Lugs (randomized) 6 min. per stage, 5 min. rest period Stance/ Swing cycle was observed (Casio EXFH20 210Hz)

Results No statistical significance was found in improving performance 10 of the 12 subjects did experience a greater running economy Of those, 3 had a >3.9% improvement

Results Continued Stance vs. Swing Stance vs. Swing

Results Continued Average RPE

Results Continued AVG HR Start AVG HR Finish

Discussion There was some improvement but why? Can there be more improvement?

Future Work Examine the biomechanics of the runners (heel striking vs. forefoot) More subjects How does it convert to performance

References 1 Newton Running. Available at www.newtonrunning.com 2 Stefanyshyn et. al. Energy Aspects Associated With Sport Shoes. Sportverletz Sportschaden [Pub Med]. 2000 82-89. Available at http://www.ncbi.nlm.nih.gov/pubmed/11081244 3 Frederick E C. Kinematically Mediated Effects of Sport Shoe Design: A Review. J Sports Sci [Pub Med]. 1986 169-194. Available at http://www.ncbi.nlm.nih.gov/pubmed/3586110 4 Frederick et. al. Lower Oxygen Demands of running in soft-soled shoes. Br J Sports Med [Pub Med]. 2008. Available at http://www.ncbi.nlm.nih.gov/pubmed/18801775 5 Yoder et. al. Differences in Plantar Loading Between Training Shoes and Racing Flats at a Self-selected Speed. Gait & Posture [Science Direct]. 2009 512-519. Available at http://www.sciencedirect.com/science/article/B6T6Y-4VCH3C1-1/2/ea473754f7eb23e1324704ea47b5f3f1

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