The Aging Diver
“When will I be too old to dive?” It’s a question we all ponder. Thankfully, there isn’t a definite answer to that question. The time to hang up your fins is different for every individual. This article will attempt to show you what limitations occur as we age and how to deal with them to keep enjoying the sport of scuba diving we all love for as long as possible.
Benefits of Diving
First of all, there are a great number of reasons to continue to dive as we age if it can be done safely. Diving is a great motivator for some people to stay in shape. Remember, you stay in shape to dive. You don’t dive to stay in shape.
Secondly, diving promotes intellectual stimulation. Advancing one’s level of certification, learning new skills like photography or fish identification promotes and retains critical thinking skills.
Thirdly, scuba diving promotes emotional well-being and social involvement (buddies, dive clubs, etc.) that can become very important as we age and lose or become geographically separated from family and friends.
As I mentioned, there is no arbitrary upper age limit to diving. An individual’s capability and health should guide them. What is their strength and physical work capacity? What chronic diseases have they developed? How is their cognitive function? What we all need is medical oversight, an honest and critical self-appraisal of our capabilities, and recognizing the limits to current knowledge of factors like decompression physiology.
As an example….
Physiology of Aging
From a medical standpoint, there are some features of aging we can’t avoid. Our aerobic capacity drops about 1% per year after the age of 25. However, regular physical activity can blunt this response. In a study of elite male athletes, it was found that those that became less active as they aged had a drop in aerobic capacity of about 1.6% per year compared to 0.7% per year in those that continued to exercise as they aged. Loss of strength and endurance follow a similar pattern. As a result, we should target four key categories as we age – strength, aerobic exercise, flexibility, and weight management. This alone can dramatically help our ability to continue to dive as we advance in years. As I tell my patients, when it comes to choosing activities in each of these areas you should “pick the one you like the most or pick the one you hate the least”. You can improve your strength by manual labour, weight lifting, kayaking or climbing to name a few. Running, cycling, and swimming all aid in aerobic conditioning. Flexibility improves with activities such as yoga, karate, volleyball, racquetball, and squash. Weight management involves “calories in and calories out”. Our metabolism decreases as we age so we have to consume fewer calories and/or burn more calories to maintain the same weight. Exercise is important but weight loss for most people is about 80% diet and 20% exercise. Fad diets don’t work because after people lose weight on these diets they often go back to the same diet they had before and their weight goes right back to what it was before. Weight management has to be a lifestyle change, not the latest fad diet.
When it comes to lung function with aging, Divers Alert Network organized an Aging Diver study but the results from that study are hard to interpret as they were unable to find “unfit” older divers. Only “fit” divers enrolled in the study. The research concerns were the lung function and carbon dioxide retention in older divers. There is data from a study by Mummer et al in 2003 comparing physically fit older divers to young divers at rest and exercise at the equivalent of 60 feet of saltwater (2.8 ATA). That study showed that older subjects had increased dead space in their lungs but there were similar patterns of carbon dioxide retention in both groups.
Our bodies aren’t as efficient at regulating body temperature as we age. A difference in thermoregulatory response has been seen between older and younger divers in a study by Pokanowicz in 2003 with higher mean skin temperatures in the older group suggesting a weaker peripheral response that may exacerbate heat loss. Thankfully, this issue with aging is easy to correct – move to diving in warmer water or simply wear more thermal protection than when you were younger.
Unfortunately, our cognitive capabilities decline through aging in terms of our ability to learn and retain, mental processing speed, and our mental flexibility. These issues can be blunted by engagement with new things, sound nutrition, physical exercise, and mental exercises – like maybe learning the latest features on your new dive computer!
As anyone over 40 can attest, our near vision worsens with age. This can make it difficult to read gauges or dive computers while diving. Thankfully, a lot of manufacturers have realized this and made options for larger fonts on their products. Alternatively, one can have corrective eye surgery, wear contact lenses, or put corrective lenses in their dive mask.
Aging also leads to decreased hearing and some studies have shown worsened hearing or accelerated hearing loss in professional divers. It turns out the primary hazard/insult is noise exposure for professional divers, not scuba diving. For sport divers, there is no suggestion of worsening of hearing compared to controls.
Orthopedic issues also increase as we age resulting in decreased flexibility, strength, and mobility. These issues, however, can be addressed with gear selection such as moving from back mount to side mount, doffing and donning gear in the water, and having assistance by buddies or dive masters with transportation of gear, donning fins, etc.
Diving with Chronic Diseases
Next comes the issue of chronic diseases that are frequent with aging. In this regard, I will briefly discuss three very common medical conditions in the aging diver – diabetes mellitus, coronary artery disease, and atrial fibrillation.
Historically, diabetes mellitus was considered an absolute contraindication to scuba diving. However, it has been demonstrated that some diabetics can dive safely. The major risk in diving with diabetes is developing hypoglycemia (low blood sugar) while underwater, not hyperglycemia (high blood sugar). In this regard it is recommended that diabetics who wish to dive should be on medications not prone to cause hypoglycemia, they should test their blood glucose frequently during the diving day, and they should carry with them some form of glucose they could consume should they develop symptoms of hypoglycemia underwater. Of note, the diabetic medications NOT associated with frequent development of hypoglycemia include metformin, the DPP-4 inhibitors (Januvia, Onglyza, Tradjenta, Nesina), and the GLP-1 receptor agonists (Byetta, Lyxumia, Victoza). For a complete review of diving with diabetes, read the DAN proceedings from 2005 (https://www.diversalertnetwork.org/files/UHMS_DAN_Diabetes_Diving_2005_Workshop_Proceedings.pdf)
A summary of recommendations is listed here
Coronary Artery Disease
Coronary artery disease is the number one killer in the western world and divers are not immune. There are certain risk factors for developing coronary artery disease that we cannot control like aging and family history. After all, none of us pick our parents. Other risk factors like high blood pressure, diabetes, and high cholesterol can be controlled with lifestyle changes and medications. Finally, if you smoke, you can quit.
If you develop coronary artery disease, even if it requires coronary artery stenting or coronary bypass surgery, you can still dive safely if you meet certain criteria. You should either be able to achieve 13 METS on exercise testing (about 12 minutes on a standard Bruce treadmill protocol) or at least be able to sustain 6.5 METS for 20 minutes (that’s equivalent to walking 2 miles in about 20 minutes). Divers who have coronary artery disease and have exercise-induced angina, have a history of a heart attack with a weakened heart muscle, or have certain exercise-induced rhythm abnormalities should not dive. However, if a diver with a history of coronary artery disease has good exercise tolerance without angina, no evidence of a limitation to blood flow on exercise testing, and normal heart muscle function, he or she can safely return to recreational scuba diving though they should be aware that they have an increased risk compared to their peers without coronary artery disease. They should also discuss with their cardiologist the idea of exercise stress testing on an annual basis.
Atrial fibrillation is an irregular heart rhythm whose most common risk factor is advancing age, along with hypertension (present in approximately 50% of adults in the United States), and underlying coronary artery disease. This abnormal rhythm can be controlled with heart rate slowing medications like beta-blockers or calcium blockers, true rhythm stabilizing drugs, or ablation procedures. While this heart rhythm can be very annoying, it is not life-threatening. However, atrial fibrillation increases a person’s risk of stroke about 5-fold. The absolute stroke risk can be estimated based on age, gender, and several medical conditions. Most patients with atrial fibrillation have an indication to take blood-thinning medications such as warfarin, Pradaxa, Xarelto, or Eliquis. Neither atrial fibrillation nor being on blood thinners are absolute contraindications to diving. Yes, should the diver suffer physical trauma or barotrauma they will bleed more than a diver not on blood thinners. However, this is almost always nuisance bleeding and not a life-threatening problem.
Studies by Carturan in 2002 and Cameron in 2007 demonstrated that the presence of venous gas emboli correlated with age. Additionally, patent foramen ovale has been found to be larger in older persons, possibly due to age-related elevations in right heart pressures. This just means that older divers need to dive more conservatively than when they were younger. This would include diving nitrox on air tables, multi-level diving rather than square profiles, shorter dives, shallower dives, fewer dives per day, and making longer safety stops. For technical divers, this would include “padding” decompression and diving with more conservative gradient factors.
There is no absolute age when a diver must hang up their fins. The most important thing for divers as they age is to make a critical self-appraisal of their medical and physical fitness, their motivation for continued diving, their diving goals, and their diving abilities. They may need to change their gear configuration and/or their diving style, but a commitment to readiness can lengthen their diving career and conservative habits can minimize their risk.