Aerobic capacity is important. There are very real limits as to the type of research that you’re suggesting – these are both ethical and practical in nature. Also, research is both time consuming and expensive to conduct. Funding is finite, and the whitewater-related research that you suggest, while very interesting, would have a low probability of getting funded. You also can’t determine the aerobic capacity of a drowning victim. And since drownings occur in a variety of circumstances on wildly different rivers, standardization is going to be very elusive. What would be far easier to accomplish – and illuminating – is a study that compared flush drownings on cold rivers with wearing or not wearing thermal protection.

I would say that the “correlation between cold water and drowning” is not only valid, but very well established. The physiological response has been well-researched by environmental physiologists, and the mechanism has been explained in detail. The cold water connection is best understood when one recognizes that cold shock is synonymous with a complete loss of breathing control. One aspect of this is a greatly diminished ability to hold one’s breath.

It’s possible to acclimate to cold water and either reduce or eliminate the cold shock response. We discuss that here: https://www.coldwatersafety.org/acclimation-to-cold-water. When being flushed through rapids, aerobic capacity matters – the key element being “How long can you hold your breath?” Also, we know a lot about drowning, and the phenomenon of sudden cold water drowning has been succinctly described for decades.

To fully appreciate that danger, it’s necessary to understand two things: 1) Without thermal protection, most people will experience maximum-intensity cold shock when immersed in 50F – 60F (10 – 15C) water. 2) Cold shock is best understood as a complete loss of breathing control. It’s characterized by gasping, hyperventilation, and a greatly reduced ability to hold your breath. These are well-documented scientific facts. Loss of breathing control also causes swimming failure.

Now, imagine all these completely involuntary responses [you can’t control them] occurring as you’re being flushed through rapids, repeatedly submerged and overwashed by waves. It’s a combination that greatly increases the potential for inhaling water and suddenly drowning.

We discuss all of this in great detail on our website: http://www.coldwatersafety.org. The site has been live on the internet for almost 12 years. I believe it’s wise for anyone who plans on researching or writing about cold water safety to make sure that they’re very familiar with the information that’s available there.

I think you’ve also hit several nails on the head, Tracy. Have studies been done to check, initially, for correlation between general/cardiac fitness and drownings, or how long into the trip and drownings?
What about checking the blood oxygen levels of paddlers of varying fitness against time into the trip? Would this give any indication of how they would fare if they then had a swim?

Also, cardiac output is a measure of fitness that was not mentioned in the article. I would like to see an article written about what aspects of fitness serve to impact one’s ability to survive in cold water etc.

There is not enough written on the fitness traits that do serve to engender survival in cold water. These studies do exist.

The bottom line is that whitewater paddlesport is somewhat behind in reporting the human performance requirements to safely preform and excel in the sport.

It is possible to gain a great deal of technical expertise in paddle sports without having the fitness to manage in an adverse situation.

People spend time to prefect the ideal sport specific skill set without training the needed auxiliary fitness components to be able to manage in the varied environments where the rivers exist.

To most paddlers the fitness requirements for safe river travel are unknown.

This is in my mind what the deficit is. The reality is that paddling is not just a “recreational” endeavor like golf. Even the recreational user needs to have a base level of fitness to engage and even survive in the less than ideal environments that sometimes exist in nature.

The sudden shock of cold can cause involuntary reactions in the autonomic nervous system, whether in air or water, that nobody can be trained to overcome. But, you can wear the appropriate attire, and that definitely means whatever number and thickness of base layers you wear under a drysuit, or even a wetsuit, to insulate your core from cold water exposure.

The truth is that nobody really knows the true facts about any drowning because the only person who does know is not talking. I am actually contemplating getting and carrying attached to my body, but out of the way, a SpareAir 3.0 or 6.0 liter SCBA system to make sure I have clean, fresh air to breath when I am under water because I have had a LONG swim underwater from which I was certain I would not come back alive. The water was not cold, but when I ran out of air I instinctively and involuntarily opened my mouth and gasped for air taking in water in the process before fighting my way to the surface. Regardless of arguments over how and why people drown just take every precaution to prevent swimming and be prepared when you do. If your number is up the rest does not matter anyway!