Regular and intense exercise is critical to maintaining fitness to dive and minimizing your risk of DCS or other injuries sustained during a dive. You need to be able to kick against currents, carry heavy dive gear, and gear up on a rocking boat comfortably to manage those conditions, and possible emergencies that could arise. Scheduling exercise and diving can be difficult however, and exercise in some cases can increase your risk of bubble formation, which is correlated with the risk of DCS. While exercising after diving may increase your risk of DCS, exercising during before a dive and during a safety stop may actually decrease your risk of decompression sickness and keep you happy and fit to dive. How much do you know about exercise and diving?
Regular and intense exercise before diving is how you establish a baseline of physical fitness. You’ll be more comfortable in the water, better able to respond to emergencies, and your air consumption will be better if you increase your physical and cardiovascular fitness. In addition, physical fitness has been associated with decreased incidence and severity of DCS, and decreased post-dive bubble formation. Some studies have shown preliminary evidence that intense exercise conducted 24 hours before diving may additionally reduce the number of bubbles formed after a dive as well, further reducing your risk of DCS. While this data still needs to be validated, no evidence exists to indicate that exercise performed within 24 hours before a dive provides a similar benefit, so it may be wise to schedule intense exercise 24 hours before a dive but not sooner. If this data proves not to be valid, exercising 24 hours before a dive will at the very least continue your exercise regimen and increase your fitness while allowing you time to rest before a dive.
During and after diving:
Physical activity during a dive has a direct impact on decompression safety. Working hard during the descent and bottom portion of the dive will increase your inert gas uptake and effectively increase your decompression obligation. Dive tables and computers estimate inert gas uptake, so this increased risk is difficult to measure but divers who work hard during a dive should consider adding conservatism to their dive with the use of nitrox, additional time at a safety stop, or a shorter than planned bottom time. Lightly exercising while on a safety or decompression stop can increase inert gas elimination and reduce your risk, but more is not better and exercising too hard can stimulate bubble formation and increase your risks significantly. Lightly finning, stretching, and moving your arms and legs around is a good way to stay moving in the water, and it will keep you warm and entertain your dive buddy. After a dive always keep your effort levels low and avoid unneeded exercise to minimize the risk of bubble formation, and relax after an enjoyable dive.
For more information on exercise and diving, visit DAN.org/Health.