Gait-Cycle Characteristics and Running Economy in Elite Eritrean and European Runners

2015 ◽  
Vol 10 (3) ◽  
pp. 381-387 ◽  
Author(s):  
Jordan Santos-Concejero ◽  
Jesús Oliván ◽  
José L. Maté-Muñoz ◽  
Carlos Muniesa ◽  
Marta Montil ◽  
...  
Keyword(s):  
Contact Time ◽  
Stride Length ◽  
Current Data ◽  
Running Economy ◽  
Stride Frequency ◽  
Ground Contact ◽  
Gas Exchange Parameters ◽  
Long Distance ◽  
Swing Time ◽  
Ground Contact Time

Purpose:This study aimed to determine whether biomechanical characteristics such as ground-contact time, swing time, and stride length and frequency contribute to the exceptional running economy of East African runners.Methods:Seventeen elite long-distance runners (9 Eritrean, 8 European) performed an incremental maximal running test and 3 submaximal running bouts at 17, 19, and 21 km/h. During the tests, gas-exchange parameters were measured to determine maximal oxygen uptake (VO2max) and running economy (RE). In addition, ground-contact time, swing time, stride length, and stride frequency were measured.Results:The European runners had higher VO2max values than the Eritrean runners (77.2 ± 5.2 vs 73.5 ± 6.0 mL · kg−1 · min−1, P = .011, effect sizes [ES] = 0.65), although Eritrean runners were more economical at 19 km/h (191.4 ± 10.4 vs 205.9 ± 13.3 mL · kg−1 · min−1, P = .026, ES = 1.21). There were no differences between groups for ground-contact time, swing time, stride length, or stride frequency at any speed. Swing time was associated with running economy at 21 km/h in the Eritrean runners (r = .71, P = .033), but no other significant association was found between RE and biomechanical variables. Finally, best 10-km performance was significantly correlated with RE (r = –.57; P = .013).Conclusions:Eritrean runners have superior RE compared with elite European runners. This appears to offset their inferior VO2max. However, the current data suggest that their better RE does not have a biomechanical basis. Other factors, not measured in the current study, may contribute to this RE advantage.

Shorter Ground Contact Time and Better Running Economy

2018 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Martin Mooses ◽  
Diresibachew W. Haile ◽  
Robert Ojiambo ◽  
Meshack Sang ◽  
Kerli Mooses ◽  
...  
Keyword(s):  
Contact Time ◽  
Running Economy ◽  
Ground Contact ◽  
Ground Contact Time

Hopping frequency in humans: a test of how springs set stride frequency in bouncing gaits

1991 ◽  
Vol 71 (6) ◽  
pp. 2127-2132 ◽  
Author(s):  
C. T. Farley ◽  
R. Blickhan ◽  
J. Saito ◽  
C. R. Taylor
Keyword(s):  
Elastic Energy ◽  
Contact Time ◽  
The Body ◽  
Force Platform ◽  
Stride Frequency ◽  
Ground Contact ◽  
Muscular Force ◽  
Mass System ◽  
Ground Contact Time ◽  
The Cost

The storage and recovery of elastic energy in muscle-tendon springs is important in running, hopping, trotting, and galloping. We hypothesized that animals select the stride frequency at which they behave most like simple spring-mass systems. If higher or lower frequencies are used, they will not behave like simple spring-mass systems, and the storage and recovery of elastic energy will be reduced. We tested the hypothesis by having humans hop forward on a treadmill over a range of speeds and hop in place over a range of frequencies. The body was modeled as a simple spring-mass system, and the properties of the spring were measured by use of a force platform. Our subjects used nearly the same frequency (the “preferred frequency,” 2.2 hops/s) when they hopped forward on a treadmill and when they hopped in place. At this frequency, the body behaved like a simple spring-mass system. Contrary to our predictions, it also behaved like a simple spring-mass system when the subjects hopped at higher frequencies, up to the maximum they could achieve. However, at the higher frequencies, the time available to apply force to the ground (the ground contact time) was shorter, perhaps resulting in a higher cost of generating muscular force. At frequencies below the preferred frequency, as predicted by the hypothesis, the body did not behave in a springlike manner, and it appeared likely that the storage and recovery of elastic energy was reduced. The combination of springlike behavior and a long ground contact time at the preferred frequency should minimize the cost of generating muscular force.

Photocell Contact Mat: A New Instrument to Measure Contact and Flight Times in Running

1997 ◽  
Vol 13 (2) ◽  
pp. 254-266 ◽  
Author(s):  
Jukka T. Viitasalo ◽  
Pekka Luhtanen ◽  
Harri V. Mononen ◽  
Kare Norvapalo ◽  
Leena Paavolainen ◽  
...  
Keyword(s):  
Ground Level ◽  
Force Platform ◽  
Stride Frequency ◽  
Ground Contact ◽  
Long Distance ◽  
Long Distance Running ◽  
Coefficients Of Variation ◽  
New Instrument ◽  
Ground Contact Time ◽  
Contact Parameters

A new instrument, the photocell contact mat (PCM), was developed to measure ground contact time and flight time as well as step and stride frequency as a function of running time or running distance. The purpose of this study was to evaluate the validity and accuracy of PCM measurements against simultaneous force platform measurements. Effects of striking pattern (sprinter or long-distance), running velocity, and height of the PCM from ground level on the contact parameters were analyzed. One male sprint runner and one male distance (marathon) runner volunteered as subjects. The time difference between the PCM and force platform determinations linearly increased as a function of the PCM height and decreased as a function of running velocity (except for the lowest 10 mm PCM height). The low coefficients of variation found between corrected PCM contact times and force platform contact times suggested that the PCM is an accurate instrument to measure ground contact times.

DIFFERENCES IN GROUND CONTACT TIME EXPLAIN THE LESS EFFICIENT RUNNING ECONOMY IN NORTH AFRICAN RUNNERS

2013 ◽  
Vol 30 (3) ◽  
pp. 181-187 ◽  
Author(s):  
Jordan Santos-Concejero ◽  
Cristina Granados ◽  
Jon Irazusta ◽  
Iraia Bidaurrazaga-Letona ◽  
Jon Zabala-Lili ◽  
...  
Keyword(s):  
Contact Time ◽  
Running Economy ◽  
Ground Contact ◽  
North African ◽  
Ground Contact Time

scholarly journals Running Economy Strongly Related to Ground Contact Time Imbalances

2019 ◽  
Vol 51 (Supplement) ◽  
pp. 792
Author(s):  
Dustin P. Joubert ◽  
Nicholas A. Guerra ◽  
Eric J. Jones ◽  
Erica G. Knowles ◽  
Aaron D. Piper
Keyword(s):  
Contact Time ◽  
Running Economy ◽  
Ground Contact ◽  
Ground Contact Time

scholarly journals Long Ground Contact Time Enhances Running Economy at High-Intensity Running

2018 ◽  
Vol 50 (5S) ◽  
pp. 772
Author(s):  
Fumiya TANJI ◽  
Hayato OHNUMA ◽  
Ryosuke ANDO ◽  
Tatsuaki IKEDA ◽  
Yasuhiro SUZUKI
Keyword(s):  
High Intensity ◽  
Contact Time ◽  
Running Economy ◽  
Ground Contact ◽  
Ground Contact Time

Validation of Garmin Fenix 3 HR Fitness Tracker Biomechanics and Metabolics (VO2max)

2020 ◽  
Vol 3 (4) ◽  
pp. 331-337 ◽  
Author(s):  
Bryson Carrier ◽  
Andrew Creer ◽  
Lauren R. Williams ◽  
Timothy M. Holmes ◽  
Brayden D. Jolley ◽  
...  
Keyword(s):  
Contact Time ◽  
Stride Length ◽  
Percentage Error ◽  
Vertical Oscillation ◽  
Ground Contact ◽  
Ground Contact Time ◽  
Fitness Tracker ◽  
System Variables ◽  
Post Hoc ◽  
Running Biomechanics

The purpose of this study was to determine the validity of the Garmin fēnix® 3 HR fitness tracker. Methods: A total of 34 healthy recreational runners participated in biomechanical or metabolic testing. Biomechanics participants completed three running conditions (flat, incline, and decline) at a self-selected running pace, on an instrumented treadmill while running biomechanics were tracked using a motion capture system. Variables extracted were compared with data collected by the Garmin fēnix 3 HR (worn on the wrist) that was paired with a chest heart rate monitor and a Garmin Foot Pod (worn on the shoe). Metabolic testing involved two separate tests; a graded exercise test to exhaustion utilizing a metabolic cart and treadmill, and a 15-min submaximal outdoor track session while wearing the Garmin. 2 × 3 analysis of variances with post hoc t tests, mean absolute percentage errors, Pearson’s correlation (R), and a t test were used to determine validity. Results: The fēnix kinematics had a mean absolute percentage errors of 9.44%, 0.21%, 26.38%, and 5.77% for stride length, run cadence, vertical oscillation, and ground contact time, respectively. The fēnix overestimated (p < .05) VO2max with a mean absolute percentage error of 8.05% and an R value of .917. Conclusion: The Garmin fēnix 3 HR appears to produce a valid measure of run cadence and ground contact time during running, while it overestimated vertical oscillation in every condition (p < .05) and should be used with caution when determining stride length. The fēnix appears to produce a valid VO2max estimate and may be used when more accurate methods are not available.

scholarly journals Attempting To Acutely Manipulate Ground Contact Time Imbalances Impairs Running Economy

2020 ◽  
Vol 52 (7S) ◽  
pp. 219-219
Author(s):  
Dustin P. Joubert ◽  
Broderick L. Dickerson ◽  
Eric J. Jones ◽  
Dani D. Willis
Keyword(s):  
Contact Time ◽  
Running Economy ◽  
Ground Contact ◽  
Ground Contact Time

scholarly journals Associations between Well-Being State and Match External and Internal Load in Amateur Referees

2021 ◽  
Vol 18 (6) ◽  
pp. 3322
Author(s):  
Eñaut Ozaeta ◽  
Javier Yanci ◽  
Carlo Castagna ◽  
Estibaliz Romaratezabala ◽  
Daniel Castillo
Keyword(s):  
External Load ◽  
Contact Time ◽  
Well Being ◽  
Ground Contact ◽  
Internal Load ◽  
Match Play ◽  
Power Meter ◽  
Ground Contact Time ◽  
Training Impulse ◽  
External Loads

The main aim of this paper was to examine the association between prematch well-being status with match internal and external load in field (FR) and assistant (AR) soccer referees. Twenty-three FR and 46 AR participated in this study. The well-being state was assessed using the Hooper Scale and the match external and internal loads were monitored with Stryd Power Meter and heart monitors. While no significant differences were found in Hooper indices between match officials, FR registered higher external loads (p < 0.01; ES: 0.75 to 5.78), spent more time in zone 4 and zone 5, and recorded a greater training impulse (TRIMP) value (p < 0.01; ES: 1.35 to 1.62) than AR. Generally, no associations were found between the well-being variables and external loads for FR and AR. Additionally, no associations were found between the Hooper indices and internal loads for FR and AR. However, several relationships with different magnitudes were found between internal and external match loads, for FR, between power and speed with time spent in zone 2 (p < 0.05; r = −0.43), ground contact time with zone 2 and zone 3 (p < 0.05; r = 0.50 to 0.60) and power, speed, cadence and ground contact time correlated with time spent in zone 5 and TRIMP (p < 0.05 to 0.01; r = 0.42 to 0.64). Additionally, for AR, a relationship between speed and time in zone 1 was found (p < 0.05; r = −0.30; CL = 0.22). These results suggest that initial well-being state is not related to match officials’ performances during match play. In addition, the Stryd Power Meter can be a useful device to calculate the external load on soccer match officials.

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