18-Jan-2007
The influence of physical fitness of a diver on DCS incidence is well known since the late 70-th. But during the last few years there has been some studies made in Norway and in Croatia that showed the influence of a single exercise prior the dive on the growth of bubbles and thus the risk of DCS.
Studies on rats that were compressed in a hyperbaric chamber to 60m for 45min breathing air and than decompressed at the rate 5m/min showed that a single 1h exercise 20h before a dive significantly reduced the bubble growth. There was no effect of exercise 48, 10, 5 or half an hour before a dive.
Studies on human divers showed that a single 1h exercise 24h before the simulated air dive on 18m for 80min with 3m/7min deco, caused the reduction of the number of micro bubbles in the pulmonary artery by more then 75 per cent and their grade by 50 per cent.
The tests showed that even a sedentary diver could greatly reduce the risk of DCS with physical activity on the day before dive.
Sources: Exercise and nitric oxide prevent bubble formation: a novel approach to the prevention of decompression sickness? NOS inhibition increases bubble formation and reduces survival in sedentary but not exercised rats Aerobic exercise before diving reduces venous gas bubble formation in humans
