It now appears from the most recent data that there is probably no difference in running economy between barefoot or minimalist running and traditional shoe running; and now we have a study showing that there is no difference in running economy between heel and forefoot striking. This study has been around for over a year now and we have been hearing about it at conferences, so its good to see it published in full. Here is the abstract:
Economy and rate of carbohydrate oxidation during running with rearfoot and forefoot strike patterns
Allison H. Gruber, Brian R. Umberger, Barry Braun, and Joseph Hamill
Journal of Applied Physiology May 16, 2013
It continues to be argued that a forefoot (FF) strike pattern during running is more economical than a rearfoot (RF) pattern; however, previous studies using one habitual footstrike group have found no difference in running economy between footstrike patterns. We aimed to conduct a more extensive study by including both habitual RF and FF runners. The purposes of this study were to determine if there were differences in running economy between these groups and if running economy would change when they ran with the alternative footstrike pattern. Nineteen habitual RF and 18 habitual FF runners performed the RF and FF patterns on a treadmill at 3.0, 3.5, and 4.0 m•s-1. Steady-state rates of oxygen consumption (VO2, ml•kg-1•min-1) and carbohydrate contribution to total energy expenditure (%CHO) were determined by indirect calorimetry for each footstrike pattern and speed condition. A mixed-model ANOVA was used to assess the differences in each variable between groups and footstrike patterns (α=0.05). No differences in VO2 or %CHO were detected between groups when running with their habitual footstrike pattern. The RF pattern resulted in lower VO2 and %CHO compared to the FF pattern at the slow and medium speeds in the RF group (P<0.05) but not in the FF group (P>0.05). At the fast speed, a significant pattern main effect indicated that VO2 was greater with the FF pattern than the RF pattern (P<0.05) but %CHO was not different (P>0.05). The results suggest that the FF pattern is not more economical than the RF pattern.
What is unique about this study is that they did not take a group of heel strikers and measure economy and then do an acute intervention and get them to forefoot strike and measure economy. They used two groups: a typical rearfoot striking group and a typical forefoot striking group. They then measured their running economy in their preferred foot strike pattern; and then got them to run in the opposite strike pattern. Heel striking was more economical for both groups!
Amby Burfoot over at Runners World covered this study a few days ago and had some quotes from the lead author to explain the results. One of them was interesting:
Gruber raises one more point about rearfoot running. Her study shows that it appears to burn less carbohydrate than forefoot running. Since carbohydrate-sparing is the name of the game in long-distance races like the marathon, she believes rearfoot running could lead to improved marathon times.
Bottom-line: “Running with a [rearfoot] pattern might confer benefits in endurance events in both habitual [rearfoot] and [forefoot] runners,” writes Gruber.
Also interesting in Amby Burfoot review of the study was the interpretation of the study in the comments section by those who are not familiar with the interpretation of research. The response in social media to research that conflicts with ones world view is always intriguing to follow. It has the usual trope of fallacies and misunderstandings re things like sample size (which I responded to and there is nothing wrong with the sample size. They would have been happy with the sample size if the results were the opposite!); injuries got a mention (it was not even a study on injuries and we now know that the injury rates between heel and forefoot strikers are probably the same). There is also the usual smattering of comments that the research is irrelevant as they ‘forefoot strike’ and do just fine, therefore everyone should be doing it. Peter Larsen recently did a brilliant summary of the issues around that attitude: Be Careful About Converting Your Experience into a Prescription for All Runners.
As always, I go where the evidence takes me until convinced otherwise.
Gruber AH, Umberger BR, Braun B, & Hamill J (2013). Economy and rate of carbohydrate oxidation during running with rearfoot and forefoot strike patterns. Journal of applied physiology (Bethesda, Md. : 1985) PMID: 23681915