Article
Blood Pressure in Sportsdivers under Water higher than on Land
Blutdruck bei Sporttauchern im Wasser höher als an Land
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Published: | November 11, 2004 |
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Outline
Text
Background
A lot of attempts have been made to measure physical stress of immersed men and to compare it with non-immersed. Because of an increasing number of sportsdivers in Germany (about 1.5 million), fitness to dive testing becomes more and more important. Besides others bicycle stress tests are used to show physical fitness. To our knowledge none of the existing studies was able to measure blood pressure continuously in a stress test under water and compare it to data found in standard bicycle tests on land.
Materials and Methods
We adapted a standard ergometer for underwater use (whole body immersion) and stressed the tested person (n=31) with defined workload above and under water. We also developed special valves to measure oxygen uptake, blood pressure and heart rate during exercise under water.
The tested person was asked to spin against the resistance of the ergometer on land (dry) and in a second attempt in water (wet). The capacity was stepwise increased by 30 Watts every 3 minutes, until the individual reached the maximum tolerable workload.
Results
The parameters found during standardised spiro-ergometry test on land (dry) with the above-described test in a depth of 117 kPa (1.7 meters) (wet) were compared in the test group. Systolic blood pressure "wet" compared to "dry" [Fig. 1] at the same O2-uptake level was significantly higher at rest (D25mmHg) as well as under maximum stress (D45mmHg). Comparing gross-capacity (adjusted Watt at the ergometer, plus additionally 32 Watt water resistance of ergometer) "wet" to "dry" by using the systolic blood pressure, we found systolic blood pressure highly significant elevated "wet" to "dry". Additionally the heart rate was significantly higher in "wet" compared to "dry" tests.
Conclusion
Comparable workload lead to significant higher blood pressure and heart rate levels in underwater strain compared to identical activity on land. Person with risk factors related to high blood pressure should be selected "not fit for diving".
Remark
The study was proved by the ethic committee of Göttingen University. All technical equipment was pre-testing checked by TÜV Hanover.