It’s a delicate, nuanced, question. How fit should you be to scuba dive? Scuba diving is a fantastic, adventurous, hobby in part because there isn’t a significant physical barrier to entry. Buoyancy levels the playing field allowing people of all physical abilities to participate in the sport.
The flip side of this is that there are a lot of good divers out there who are pretty unfit. This extends all the way up the qualification tree from novices to advanced instructors.
Fitness to dive is normally discussed only in the medical sense: do you have any underlying health conditions that significantly raise the risk while diving? The medical disclaimer everyone skims through and signs before diving. Outside of military and commercial diving there is very little discussion about actual fitness and its impact on safety.
A good level of physical fitness is a fundamental aspect of dive safety that isn’t talked about enough.
Why is fitness important?
Scuba diving is generally a pretty relaxed activity. When enjoying the clear waters of the tropics you probably might not expect for your heart rate to raise at all. However, even the calmest dive will still have an element of physicality to it: climbing into and out of boats, swimming into currents and carrying heavy equipment needs at least a basic level of fitness. A good level of fitness makes it all that bit easier and more enjoyable.
The real role that good fitness plays is in safety. The cardiovascular system is the focal point of many of the risks of scuba diving, such as decompression sickness (DCS). A good level of physical fitness is thought to lower the related stress on the cardiovascular system and risk of conditions like DCS.
Interestingly, there doesn’t appear to be great data available showing this relationship: accident reports from the likes of the BSAC and DAN don’t go into granular detail (e.g. incidence of DCI tracked against BMI or other health markers). However, a direct relationship between increased physical fitness and reduced risk is assumed.
Staying fit also reduces the risk of many of the underlying conditions that could preclude you from even diving or, if left undiagnosed, greatly increase the risk of serious injury.
The final area of safety in which fitness plays a role is emergencies. How much of an asset would you be to support a buddy or another diver in trouble? You may need to tow an unconscious diver or help recover them into a RIB. A good level of strength and fitness should benefit everyone you’re diving with.
Basic Requirements
There are slight variations but most scuba diving training agencies have a basic swim test for entry level qualifications. These aren’t timed so are really a measure of water competency rather than cardiovascular fitness:
PADI – 200m swim, any stroke no time limit and float for 10 minutes.
SSI – 200m swim, any stroke no time limit and float for 10 minutes.
BSAC – 200m swim, any stroke no time limit.
Fitness Levels
I think you can roughly breakdown diving fitness into 3 categories. This is based on the challenge, risk and the relative fitness benefit. To be clear – this is only meant to be a guide and not a prescriptive list.
Low – Holiday Diving
The easiest form of diving. Dive professionals tend to take much of the physical labour out of diving when you’re on holiday. So you’re much less likely to be carrying cylinders long distancing or pulling in shot lines. On a typical warm weather trip you’ll also be using relatively little weight lowering the strength needed to manoeuvre in full kit.
Even the most laid back diving calls for a moderate level of basic physical fitness. You should be fit enough to comfortably go on long walks or climb the stairs without getting out of breath
Medium – UK Diving/Temperate
Diving in temperate seas, such as here in the UK, can be more challenging. Colder water temperatures require drysuits, more weight, and rougher conditions are far more common. The diving can be demanding. In many scenarios, such as diving with a club, you’re also responsible for moving all the kit: compressors, boats, cylinders etc.
High – Technical Diving
Unsurprisingly, technical diving puts the greatest amount of decompression stress on the body and demands the greatest level of fitness.
Training
If you’re thinking about improving your fitness to dive it’s worth noting that strenuous activity is not recommended 24 hours either side of diving.
How you approach improving your fitness will depend on your starting point. If you’re a sedentary person it could start with simply walking more and looking to increase your general activity level. So be realistic.
You can break down training into 3 areas:
Cardio – It could be running, cycling, swimming or anything that gets you working, the aim is to increase your heart rate and breathing. It should be scaled to your ability so don’t immediately try and run a marathon if you’ve been out of training. Progressive training plans like Couch to 5k are easily available and a great place to start.
Flexibility – often overlooked until you’re trying to get into a thick wetsuit. Yoga is an obvious choice and there are plenty of free classes on YouTube to do at home.
Strength – if you haven’t done any strength training before it’s worth getting some guidance from a professional. The aim should be for a functional increase in strength so I’d recommend the basic compound exercises like deadlifts, squats and pull-ups.
Final Thoughts
Cardiovascular fitness is important to diving safety but you don’t need to be an elite athlete to be an excellent and safe diver. If you and your buddy understand your limitations and are happy – that’s great. However, improving your fitness is an opportunity for a marginal gain – a percentage point here or there that might just add up when you need it.
