For nearly two decades, sports brands benefited as people swapped out dress shoes for sneakers when heading everywhere from the airport to fancy restaurants and even the office.

That’s been a boon for Adidas, Nike and Puma, which capitalized on consumers’ changing tastes by serving up snazzy, comfy kicks that people wanted to wear on and off the playing field. The rising demand for sports shoes also underpinned the rapid growth of challengers such as Hoka and On Holding, which emerged in the wake of the financial crisis and quickly became popular brands.

Now the future of that longstanding sneaker boom is being called into question, most notably by Bank of America analysts led by Thierry Cota. They rocked the footwear world last week with a 61-page analysis concluding that the growth prospects for these sports brands are rapidly dimming.