The running economy studies on rearfoot vs midfoot/forefoot and barefoot/minimalism vs shoes have been coming thick and fast this year and they pretty much all showing the same thing. I should not need to relitigate the issues I have bloged about here, here, here, here, here and here! So straight to it: This one was just published:
Rearfoot Striking Runners Are More Economical than Midfoot Strikers
Ogueta-Alday, Ana; Rodríguez-Marroyo, José Antonio; García-López, Juan
Medicine & Science in Sports & Exercise: 30 August 2013
Purpose: To analyze the influence of foot strike pattern on running economy and biomechanical characteristics in sub-elite runners with a similar performance level.
Methods: Twenty sub-elite long-distance runners participated and were divided into two groups according to their foot strike pattern: rearfoot (RF, n= 10) and midfoot strikers (MF, n= 10). Anthropometric characteristics were measured (height, body mass, BMI, skinfolds, circumferences and lengths); physiological (V[spacing dot above]O2max, anaerobic threshold and running economy) and biomechanical characteristics (contact and flight times, step rate and step length) were registered during both incremental and submaximal tests on a treadmill.
Results: There were no significant intergroup differences in anthropometrics, V[spacing dot above]O2max or anaerobic threshold measures. RF strikers were 5.4, 9.3 and 5.0% more economical than MF at submaximal speeds (11, 13 and 15 km[middle dot]h-1 respectively, though the difference was not significant at 15 km[middle dot]h-1, p=0.07). Step rate and step length were not different between groups, but RF showed longer contact time (p<0.01) and shorter flight time (p<0.01) than MF at all running speeds.
Conclusions: The present study showed that habitually rearfoot striking runners are more economical than midfoot strikers. Foot strike pattern affected both contact and flight times, which may explain the differences in running economy.
The results are consistent with other similar recent studies such at the Gruber et al study and the Michele and Merni study. It is also consistent with the previous one that showed that Pose running (midfoot striking) was less efficient than heel striking that got the fan boys upset! (see the comments on the Pose study).
Why did they find the results they did: I presume that to get up onto the midfoot, requires more muscular effort, so its less efficient. They found no difference at the faster velocity (15km/hr) and my best guess is that the heel strikers were starting to get towards being on the midfoot to run that fast; ie more muscular effort (?), so a loss of efficiency (?).
As always, I go where the evidence takes me until convinced otherwise, and the evidence is pointing me in one direction when it comes to running economy and the various foot strike patterns or footwear conditions.
Ogueta-Alday, Ana; Rodríguez-Marroyo, José Antonio; García-López, Juan (2013). Rearfoot Striking Runners Are More Economical than Midfoot Strikers Medicine & Science in Sports & Exercise DOI: 10.1249/MSS.0000000000000139