Advertising watchdogs have banned a “potentially misleading” Reebok ad for Reezig Zigtech trainers, also ruling that the sports goods company had not provided sufficient evidence for the technology involved.

The Advertising Standards Authority (ASA) was responding to a complaint about a leaflet, which showed motor racing driver Lewis Hamilton holding one of the trainers next to text saying: “The energy drink for your feet.”

Text inside the leaflet claimed the trainers could reduce wear and tear on key leg muscles by up to 20%, and the back of the leaflet drew attention to the Celliant fibres used in the manufacture of Zigtech apparel, which it claimed could improve circulation while exercising.

The complainant challenged whether the claims for the fibres could be substantiated, and said the ad was misleading for implying the trainers had been made using Celliant.

In response, Reebok supplied two research studies to back its case, stating that all Zigtech apparel products were made with at least 42% Celliant material, but admitting that the trainers were not made with Celliant at all.

The ASA ruled the data insufficient and said further study into Celliant was warranted, adding that the reference to Celliant in conjunction with the trainers was likely to mislead the public.

“The ad must not appear again in its current form,” said the ASA. “We told Reebok to ensure they held relevant documentary evidence for claims capable of objective substantiation.

“We also told them to make clear the product to which their claims referred.”