David M. Shribman states that Ayres has "inspired athletes worldwide and reshaped our ideas about endurance and sustainability".
[7] In 1999, Ayres wrote God's Last Offer: Negotiating for a Sustainable Future in which he discusses four trends which he says threaten society: global warming caused by carbon dioxide, mass extinctions, a surge of consumption, and a population explosion.
[5] Publishers Weekly stated that "Ayres dismantles the perceptual obstructions that block our awareness of a crisis" but that he "comes up short in offering specific solutions"[5] while Goodreads said that the book "presents a blueprint for a radical shift of policies and priorities to avoid a cataclysm".
Goodreads called his book The Longest Race (2012), an autobiography covering his attempt to run a 50-mile ultramarathon at age 60, an "urgent exploration of the connection between individual endurance and a sustainable society".
[9] Kirkus Reviews said that his " broad-ranging interests and accumulated wisdom will appeal to a wide readership, not just runners and environmentalists".