be sustained

See: subsist
References in classic literature ?
So long as single warriors came against him, he was to be left to the keeping of the Wahcondah and his own arm; but should the Siouxes attack him in numbers, he was to be sustained, man for man, even to the extent of his whole force.
22]) could the virus evolve sufficient transmissibility to be sustained in the human population, which poses the greatest risk for pandemics (33).
Therefore, regular, high exposure to the pathogen from the reservoir can give the appearance of endemic infection, even if the pathogen cannot be sustained within the population (case 2: apparent multihost dynamics).
It seems to me that being able to sustain a level of effort should be based on how long (time) not how far (distance) the effort can be sustained.
Regardless of any individual runner's fitness and speed, the percentage of maximum heart rate that can be sustained over a given distance is lower the longer the distance.