Lack of adequate appreciation of physical exercise's complexitiescan pre-empt appropriate design and interpretation in scientific discovery.
I've not read the whole thing, but this statement stood out in the abstract:
Normal physiological processes are dynamic, integrated, periodic, and therefore, it is difficult to define normal physiological function by looking at a single time point or single process in a non-stressed subject.
The paper is challenging this idea of an exercise pill - this concept that a drug could be developed to mimic the beneficial effects of exercise.
The authors object:
The concept of an "exercise pill/exercise mimetic" demonstrates an inadequate appreciation for the complexities in integrating cell, tissue, organ, and systems during both acute disruptions in homeostasis by a single bout of exercise, and longer-term chronic adaptations to different types of exercise such as resistance and endurance.
We are more complex systems - there are lots of interactions going on when we exercise. You cannot separate out single elements and expect to understand the whole.
This may sound complex but I think there is also a simplicity about this. We need to move, to exercise. The movements and the exercise can be simple but the effects on our bodies may be quite complex and indeed may be predicated on complex systemic interrelationships.