Timing of exercise and diving
After accepting the need for regular exercise to maintain or improve physical fitness, the next issue concerns the timing of exercise training and diving. Scheduling outside physical fitness activities can be problematic when someone dives frequently. While part of this is simply a time management problem, there are other considerations. Conducting intense physical exercise too close to diving activity can be problematic for more fundamental reasons.
Bubble formation, while noted earlier as not equivalent to or a guarantee of DCS, can indicate an increased risk for it. Intense physical activity — generally with substantial muscular forces and joint loading, or the application of forces on joints — is believed to transiently increase micronuclei activity, the presumed agent of bubble formation. Intense physical activity too close to diving may therefore be problematic. Physical activity after diving may also stimulate additional bubble formation, possibly through a combination of increased microicronuclei activity and increased joint forces.
Interestingly, some preliminary work has shown that an intense bout of exercise conducted 24 hours prior to diving may reduce bubble presence in humans,3 possibly by inhibiting micronuclei activity. This potentially protective effect was not seen with exercise conducted closer to dive time. While this effect needs to be validated, the preliminary findings may support a simple rule of thumb for scheduling exercise. To reduce the risk, it is a good idea to avoid intense exercise 24 hours before and after diving.
The near-dive window will be best for low-intensity activities.Those who participate in cross-training activities may find it easiest to accommodate this schedule. For those who are more singleminded, diving may fit well into training rest days for those who put the priority on exercise, while training may fit best into diving rest days for those who put the priority on diving. Overall, lower training intensities will likely be more appropriate for the latter group, but accommodations can be reached.
