While we have little control over our chronological age, the same cannot be said about physiological age. Divers need to stay in good physical shape. As people age, they are more likely to reduce their activity level, and general fitness declines. As a result, many health factors related to health also decline. These include strength, endurance, flexibility and cardiovascular fitness.
Cardiovascular disease is of particular concern to the older diver.
It is thought to be responsible for up to 20 percent of all recreational diving deaths. For this reason, cardiovascular risk factors such as smoking, hypertension, high cholesterol and obesity are of even greater concern when found in older divers. Any person who is 45 or older and wishes to dive should have an exercise stress test as part of a physical exam. Poor exercise tolerance or evidence of coronary artery disease on such a test would be grounds for excluding a person from diving. The answer is not particularly clear.