ericdiver
Registered
I saw this abstract referenced on the scubadiver.com forum and looked it up, couldn't find the full article however (not yet published 10 days after epub?).
Anyway, has anyone heard of this or seen the article (or are any of the authors on scubaboard)? Of course it's only one article, with 24 subjects and 2 dives each, but still very interesting for those of us who dive and make a serious effort to maintain fitness (which of course requires regular exercise which can conflict with regular diving). These results certainly seem different from the common recommendation of waiting 24 hours before or after diving to exercise.
The hydration/dehydration sideline is interesting too.
The abstract:
Eur J Appl Physiol. 2010 Nov 24. [Epub ahead of print]
Endurance exercise immediately before sea diving reduces bubble formation in scuba divers.
Castagna O, Brisswalter J, Vallee N, Blatteau JE.
Biomedical Research Institute of the Army (IRBA), Naval Medical Institute (IMNSSA-Toulon), Departments of Operational Environment and Marine and Underwater Research, BP 20548, 83049, Toulon Cedex 9, France, castagna.olivier@gmail.com.
Abstract
Previous studies have observed that a single bout of exercise can reduce the formation of circulating bubbles on decompression but, according to different authors, several hours delay were considered necessary between the end of exercise and the beginning of the dive. The objective of this study was to evaluate the effect of a single bout of exercise taken immediately before a dive on bubble formation. 24 trained divers performed open-sea dives to 30 msw depth for 30 min followed by a 3 min stop at 3 msw, under two conditions: (1) a control dive without exercise before (No-Ex), (2) an experimental condition in which subjects performed an exercise before diving (Ex). In the Ex condition, divers began running on a treadmill for 45 min at a speed corresponding to their own ventilatory threshold 1 h before immersion. Body weight, total body fluid volume, core temperature, and volume of consumed water were measured. Circulating bubbles were graded according to the Spencer scale using a precordial Doppler every 30 min for 90 min after surfacing. A single sub-maximal exercise performed immediately before immersion significantly reduces bubble grades (p < 0.001). This reduction was correlated not only to sweat dehydration, but also to the volume of water drunk at the end of the exercise. Moderate dehydration seems to be beneficial at the start of the dive whereas restoring the hydration balance should be given priority during decompression. This suggests a biphasic effect of the hydration status on bubble formation.
A link to the pubmed listing of the abstract (which I've copied above): Endurance exercise immediately before sea diving r... [Eur J Appl Physiol. 2010] - PubMed result
Eric
Anyway, has anyone heard of this or seen the article (or are any of the authors on scubaboard)? Of course it's only one article, with 24 subjects and 2 dives each, but still very interesting for those of us who dive and make a serious effort to maintain fitness (which of course requires regular exercise which can conflict with regular diving). These results certainly seem different from the common recommendation of waiting 24 hours before or after diving to exercise.
The hydration/dehydration sideline is interesting too.
The abstract:
Eur J Appl Physiol. 2010 Nov 24. [Epub ahead of print]
Endurance exercise immediately before sea diving reduces bubble formation in scuba divers.
Castagna O, Brisswalter J, Vallee N, Blatteau JE.
Biomedical Research Institute of the Army (IRBA), Naval Medical Institute (IMNSSA-Toulon), Departments of Operational Environment and Marine and Underwater Research, BP 20548, 83049, Toulon Cedex 9, France, castagna.olivier@gmail.com.
Abstract
Previous studies have observed that a single bout of exercise can reduce the formation of circulating bubbles on decompression but, according to different authors, several hours delay were considered necessary between the end of exercise and the beginning of the dive. The objective of this study was to evaluate the effect of a single bout of exercise taken immediately before a dive on bubble formation. 24 trained divers performed open-sea dives to 30 msw depth for 30 min followed by a 3 min stop at 3 msw, under two conditions: (1) a control dive without exercise before (No-Ex), (2) an experimental condition in which subjects performed an exercise before diving (Ex). In the Ex condition, divers began running on a treadmill for 45 min at a speed corresponding to their own ventilatory threshold 1 h before immersion. Body weight, total body fluid volume, core temperature, and volume of consumed water were measured. Circulating bubbles were graded according to the Spencer scale using a precordial Doppler every 30 min for 90 min after surfacing. A single sub-maximal exercise performed immediately before immersion significantly reduces bubble grades (p < 0.001). This reduction was correlated not only to sweat dehydration, but also to the volume of water drunk at the end of the exercise. Moderate dehydration seems to be beneficial at the start of the dive whereas restoring the hydration balance should be given priority during decompression. This suggests a biphasic effect of the hydration status on bubble formation.
A link to the pubmed listing of the abstract (which I've copied above): Endurance exercise immediately before sea diving r... [Eur J Appl Physiol. 2010] - PubMed result
Eric