Medical Fitness and Scuba Diving
You don't need to be an athlete to dive, but you do need good physical health. A few medical conditions can be hazardous while diving. Also, like any activer recreation, diving can be physically demanding, so individuals who may be predisposed to heart attack or cardiovascular disease need to exercise caution. As a prudent precaution, before any inwater training, you'll complete a Medical Statement that screens for conditions that a physician / doctor should evaluate. For your safety, answer all questions honestly and completely.
If you answer ''yes'' to any condition, a physician / doctor must approve you for diving by completing and signing the statement prior to any inwater training.
Basic Swimming Skills
To be a scuba diver, you need adequate swimming skills. During your PADI Open Water diver course, you will be required to demonstrate that you can float or tread water without aids for 10 minutes, that you can swim 200 metres with no aids or 300 metres with mask, snorkel and fins.
Your Health and Fitness
Diving is relaxing and you try to dive relaxed, but it is not always slow moving, even if you plan it to be, so you need to be in good health and reasonably fit. Strenuous activity can arise, including handling gear, currents, an emergency or unanticipated physical demands. Being in good health helps assure you can meet these demands and dive safely.
Some general recommendations apply to your health and fitness as a diver.
Maintain a reasonable level of fitness. This means that you have adequate fitness, plus a physical reserve, for the type of diving you do. Participate in a regular exercise program (see your physician / doctor before starting one, however). You don't have to be a professional athlete - just in good average health.
Keep your immunisations current, especially tetanus and thyphoid.
Eat a well-balanced diet and get adequate rest, especially before diving.
It's a good idea to have a physical examination when you start diving, and regularly thereafter. Ideally, have a medical doctor knowledgeable in dive medicine conduct the examination. However, the RSTC Medical Statement provides guidelines developed by dive medical experts that any physician can use to conduct dive physicals.
Like any activity that can cause physical exertion and stress, diving can strain your heart and cardiovascular system. Factors that can do this include exertion from swimming hard, carrying equipment, climbing a ladder, long walks wearing gear, and heat stress from wearing an exposure suit in a hot climate.
These factors can cause heart attack in predisposed individuals. They can also be issues for other cardiovascular conditions.
If you have or may have risk factors that make it more likely to have heart disease due to your age, life style, body composition, family history or any other factors, be sure to discuss them with your doctor. Your physician / doctor can help you assess the risk, and how you can manage that risk as a diver.
Alcohol, Tobacco and Drugs
Never use alcohol or tobacco before diving. Alcohol affects your judgement, and its effects may increase with depth. It also accelerates body heat loss, which can be an issue on cooler dives. Be moderate if drinking the night before diving, because it tends to dehydrate you, which some physiologists think can contribute to decompression sickness risk.
Smoking is undeniably harmful to your health, and not a good choice for anyone, but particularly if you live an active lifestyle. If you do smoke, avoid doing so for several hours before and after diving, because it significantly decreases the efficiency of your circulatory and respiratory systems. Smoking theoretically raises the risk of lung overexpansion injury by causing air trapping within your lungs - even when you breathe normally. Non-smoking tobacco use, including e-cigarettes, seems to pose less immediate risk, though it's still better to simply avoid nicotine.
Drugs can create problems when diving. It's obvious that you should not be using illegal drugs. However, you also need to use prescription drugs and over-the-counter medications with caution. Any drug that affects your judgement, thinking and/or reactions should generally not be used, but many drugs have no effects that interfer with diving. Always consult your physician / doctor. If still in doubt, don't dive until you no longer use the medication.
Menstruation and Pregnancy
If menstruation doesn't normally keep you from doing other active recreations, it's not likely to affect diving either. Pregnancy differs, and it's broadly recommended that pregnant women not dive. This isn't because of a known risk, but rather because there's not enough known about how diving could affect a developing fetus. It is generally agreed that it's not worth the risk, and you should not dive while pregnant or trying to become pregnant.
Day To Day Health
You want to be in good physical and mental health when diving so that you can avoid problems and handle them if they occur. So, if you feel ill before a dive, cancel the dive. Even a cold can cause problems by trapping air, making it difficult to equalise and in some cases, increasing the risk of lung overexpansion injuries.
Don't use medication to get rid of symptoms just so you can dive while unhealthy. Get well, then resume diving.