Cameron, don't get bent out of shape. forgive the pun...
Thanks, the links you provided are a good starting point. As a physiologist, I have read and seen ample spurious claims especially since recently joining this board that are downright misleading and in the context of diving, are dangerous. "Hard science" means not to use terms like "prove" because as you indicate, there is no certainty in anything we think we know. Hard science means taking observed actions and reactions and measurable components and applying them to a hypothesis. Many times, I read artifact, subjective analysis, and "intuition" that is masked as "science".
The quoted articles support my suspected outcomes that fitness level may be associated with reduced DCS but I wonder what levels of aerobic capacity are thresholds for positive outcomes? Numerous studies indicate that regardless of aerobic capacity, exercise prior to diving may reduce the susceptibility of DCS
Dujić Z, Duplančić D, Marinović-Terzić I, Baković D, Ivanćev V, Valić Z, Eterović D, Petri N, Wisløff U, Brubakk AO. Aerobic exercise before diving reduces venous gas bubble formation in humans. J Physiol. 2004;555:637–642.
And this paper on incidence of DCS with exercise indicates contradictory benefits of during exercise (
Exercise and decompression sickness: a matter of intensity and timing).
True, researchers won't deliberately induce DCS in their human research subjects but you seem to imply that this is what science requires. Actually, microbubble formation can be measured in vivo (inside the human body) while exposed to increasing or decreasing external pressure while controlling for increased risk of DCS. So, yes, we must expose research subject to increased risk of DCS in order to understand the risk of DCS for differing populations. Would it not be irresponsible to not do so?
In a follow-up on this, what benefits other than reduced DCS are there for divers who regularly engage in aerobic exercise (who summarily have higher VO2max)?
Thanks!