They've been studying Acarbose for awhile now https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8789153/ The problem with a lot of these longevity approaches is they "solve the problem" by reducing energy conversion, like acarbose, pulling people to a baseline and preventing stress adaptations. Great for sitting around. The opposite of that for doing anything athletic, you'd never improve.
There is some evidence that "aerobic exercise" itself produces an equivalent baseline energy deficit without the performance downside. This guy[0] studies total average energy expenditure over time and demonstrates that an athlete undertaking intense regular exercise uses marginally more energy over time than someone sitting on a couch all day. The hypothesis being that the athlete is conserving energy by down-regula…
I think it points to an interesting insight, something we have yet to uncover perhaps, but I don't think it disproves that exercise spends energy. Maybe all it's really proving is that we are very efficient at the chosen type of exercise in the study.