“…What remains unclear from the scientific evidence to date [ 18 , 27 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ] is whether a running performance difference exists when including the vegan diet as an additional comparator group. Due to the vast influence of several different factors in running performance, such as genetics [ 39 ] or personal training behavior [ 40 , 41 ], observable diet type differences may be limited [ 36 , 37 ]. Previous population studies on long-distance recreational runners comparing omnivorous, vegetarian, and vegan diet types in performance have only examined a limited extent of training variables, such as weekly exercise frequency, running distance, durations, and/or professional support [ 32 , 33 , 35 ].…”