let alone set record running time what does it mean ''let alone set record running time'' and '' to be just as likely to'' in this sentence: Not only that, a second study proved that older athletes can achieve the same degree of physical improvement as those in their twenties and thirties. In other words, they are just as likely to achieve their peak fitness as younger athletes. 25 years ago few 60 year old men even fewer woman would have considered it possible to complete a marathon let alone set record running time. Thank you