Can prayer be used to augment the benefits of exercise, like it can to extend the coverage of nutritional supplements taken intermittently?

This is correct. It can be requested. It is a function of belief, do-ability from the divine side, and there needs to also be a recognition of personal responsibility. The key is the description of "augmentation." There needs to be something to augment, so an honest and good faith effort on the part of an individual is needed as a foundation, because that is what will be expanded on. So there must be something first, in order for that to be magnified and this is up to the requester to come through and make a commitment to do a basic level of work on their own behalf. That will govern how great the benefit will be. So a solid workout that is meaningful and not a token effort, can be applied again and again for a reasonable span of time. But if that is all that will happen for those days, the initial session used to launch the request needs to be a significant investment in order to make the augmented session coverage meaningful.