06/03/2023
A Comparison of Running Economy Across Seven Highly Cushioned Racing Shoes with Carbon-Fiber Plates
Another excellent research study, this one by Dustin Joubert and Garrett Jones, was recently published which compared the metabolic efficiency of running in many of the currently available running "super shoes" with carbon-fiber plates embedded within their shoe soles (Joubert DP, Jones GP. A comparison of running economy across seven highly cushioned racing shoes with carbon-fibre plates. Footwear Science. 18:1-3, 2022).
Joubert and Jones used 12 trained, male distance runners as study subjects. To meet their study subject criteria, the subjects must have run at least 3 times per week in the last 3 months and must have had a sub-17:30 5-km (5:39 mile pace) race performance or equivalent race performance. The study subjects also needed to be able to run below their lactate threshold at the tested running economy speed of 16 km/hr (6:02 mile pace).
The subjects all ran in seven super shoes including Asics Metaspeed Sky, Brooks Hyperion Elite, NB Fuel Cell RC Elite, Hoka Rocket X, Nike Alphafly Next%, Saucony Endorphin Pro, Nike Vaporfly Next%. The subjects also ran in one traditional racing shoe, the Asics Hyperspeed.
The subjects completed eight 5-minute trials wearing a different, randomly-selected shoe for each trial. All trials were run on a motorized treadmill while O2 consumption, CO2 production, ventilation, and respiratory exchange ratio were measured in each trial. In addition, ground contact time, cadence and vertical oscillation were measured. Heart rate was also measured using a validated heart rate monitor.
Results showed that the Hoka Rocket X and Brooks Hyperion Elite did not significantly lower O2 consumption compared to the Asics Hyperspeed traditional racing shoe. The New Balance Fuel Cell RC Elite, Nike Alphafly Next%, Saucony Endorphin Pro, Nike Vaporfly Next% and Asics Metaspeed all lowered O2 consumption, improving running economy. The New Balance Fuel Cell and Saucony Endorphin Pro both improved running economy by less than 1.5%. However, the Asics Metaspeed, Nike Vaporfly and Nike Alphafly shoes all improved VO2 by more than 2.5%.
Interestingly, the researchers found no relationship between metabolic cost and shoe mass. The percentage of subjects who responded with at least a 2% decrease in VO2 relative to traditional shoe were as follows: Nike Vaporfly (83.3%), Nike Alphafly (75.0%), Asics Metaspeed (66.7%), Saucony Endorphin Pro (25.0%), New Balance Fuel Cell RC (25.0%), Hoka Rocket X (0%), Brooks Hyperion Elite (0%). In addition, four of 12 subjects (25%) responded with a greater than 4% reduction in VO2 in the Nike Alphafly.
This 2022 study by Joubert and Jones clearly showed that not all super shoes are truly “super”. The Nike Vaporfly and Nike Alphafly still seem to have a competitive advantage over nearly all other super shoes with up to 4% reduction in metabolic energy. Also, the Asics Metaspeed was the only other super shoe that competed well with Nike super shoes in metabolic energy reduction. The experimental results also showed that the Hoka Rocket X and Brooks Hyperion Elite did not show significant metabolic energy savings compared to the traditional racing flat.
The authors concluded "that the current competitive running shoe market is not equal and athletes choosing to race in any of the shoes shown to be inferior to these in present line-up are likely at a competitive disadvantage." This study is the only study to date that has compared commercially available running super shoes in regards to metabolic efficiency. I expect more studies such as this to follow in the years to come.
