The impact of grounding in running shoes on indices of performance in elite competitive athletes

Muniz-Pardos et al, 2022 [double-blind, randomized, crossover design, n= 10, male, mean age of 27.7] aimed to examine the physiological and perceptual responses of athletes subjected to grounding shoes during running. Two conditions were tested: the traditional training shoe (TTS) and the grounding shoe (GS), with these being visually identical. Shoes with grounding potential contained a conductor element around the insole and included a textile webbing containing yarn in the upper area, that encouraged electrical charge to flow through the material. The material was stitched into the collar area and ran through the midsole to connect with the rubber on the outsole that contacts the ground. Also, the outsole included rubber that encouraged the flow of electrical charge. The manufacturers labelled the shoes with a number in red or blue according to the two shoe conditions, and this setting was used by the research team to keep the study design double-blind. Athletes performed running economy tests (20 min run at 80% of the anaerobic threshold) on a 400 m dirt track. VO2, heart rate, lactate, and perceived fatigue were registered throughout the experiment. However, no differences in any of the physiological or perceptual variables were identified between groups, with an equal running economy in both. The authors concluded that the results obtained suggested that grounding in shoe designs is not an effective alternative for well-trained athletes to improve their running efficiencies, and/or their  hysiological/perceptual responses during submaximal exercise. However, some limitations are pointed out, such as potential grounding effects could have been missed as running does not allow constant contact between the athlete and the ground, also that lower caliber athletes may have benefited from this technology given their ground contact times are greater than faster, elite athletes.