DCS Danger Zone?

[ScubaSteve2000]

I am an avid diver. I try to dive every Saturday. Several months ago I got interested in endurance racing (sprint triathlons). I train almost every day of the week to maintain my conditioning and to prepare for the next tri. On Sunday mornings I usually do a ride (15-20 miles) and run (5K+). This is usually after diving on Saturday.

Additional info:
My Sunday morning workouts are 16+ hours after my last dive.
If I'm diving deep on Saturday I usually do a 2-3 minute mid level stop and a 5 minute safety stop at 20'
My dives are within recreational deco limits. That is to say, no deco dives.
I usually do only two dives unless I'm on a dive trip. Then I skip my Sunday workout because I'm diving instead.
I don't dive the day before a triathlon. Race distances for sprint triathlons are usually a 400-800 meter swim followed by a 12+ mile bike ride followed by a 5K run.

I've been doing this since April of this year (3 months).

I don't seem to be suffering any ill effects. Are there "hidden" physiological issues that I should be concerned about?
I'm in great health BTW.

See you at the lake.

 

[Duke Dive Medicine]

Steve,
You're probably clean or close to it after 12 hours, and your excellent physical condition helps even more. You should be just fine. Happy training.
Best,
DDM

 

[ScubaSteve2000]

Thanks for the info.

 

[Kevrumbo]

Interesting read on Endurance Exercise and DCS Pre-Conditioning:

On Diving acclimatization and DCS:
In summary, our results show that DCS induces a stress response, as confirmed by the expression of heat-shock protein in lung, liver, and heart tissue. DCS preconditioning reduced the neurological impairment caused by subsequent rapid decompression from exposure to high pressure. We conclude that bubble formation in tissues after decompression can activate a stress response and that the protective effects derived from this stress response may be the mechanism responsible for the phenomenon of diving acclimatization. . .

Diving acclimatization has been described as an adaptive response to decompression stress after repetitive exposure to pressure (7). This adaptation reduces a diver's susceptibility to DCS or the severity of DCS. The mechanism contributing to diving acclimatization, however, remains obscure. We proposed an "induction hypothesis," speculating that repetitive compression-decompression is a form of preconditioning that generates protective factors and reduces the severity of acute tissue injury during subsequent bubble formation. In the present study, our results further demonstrate that DCS induces a stress response and that this DCS preconditioning significantly alleviates the neurological impairment induced by subsequent exposure to high pressure. These results strengthen our induction hypothesis by explaining the mechanism underlying diving acclimatization. . .

DCS is a disease caused by gas bubble formation in tissues. Air bubbles produce their effects by mechanical obstruction, by altering the biochemical environment, or both. Bubble formation interrupts blood flow and compresses or disrupts tissues (22). Air bubbles can also initiate an air-liquid interface reaction in tissues, which activates plasma proteins, including clotting factors, enzymes, and immunoglobulins (15). The complement system, polymorphonuclear leukocytes, and oxygen metabolites are proven factors that mediate air-bubble-induced tissue injury (22). Protection from air-bubble-induced tissue injury may result from a smaller number of bubbles or from less tissue reaction to air bubbles. Wisloff and Brubakk (31) reported that endurance exercise reduces bubble formation and increases survival in rats exposed to hyperbaric pressure. It is not known whether DCS preconditioning reduces bubble formation after the next episode of decompression from a hyperbaric environment. Nevertheless, endurance exercise is a stressor that increases the expression of HSP70 and may represent a powerful preventative agent against tissue injury in several models (8, 23). These reports suggest that stresses such as endurance exercise can activate bioprotective mechanisms. Compatible with these reports, our results show that prior DCS is also a stress inducer, which may activate a bioprotective mechanism similar to that induced by endurance exercise. This suggests that this protection involves mechanisms more complex than a reduction in bubble formation. . .Acclimatization to neurological decompression sickness in rabbits