PMC:4652343 / 11647-13845
Annnotations
{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/4652343","sourcedb":"PMC","sourceid":"4652343","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4652343","text":"There was mounting evidence that the mechanisms of cardiovascular compensation during stress of gravity were more compromised in individuals with high aerobic capacity compared to their less fit counterparts [13]. Our laboratory conducted seminal studies of the influence of aerobic exercise training that provided evidence of a positive effect of endurance exercise on cardiovascular responses to gravity that reversed doctrine set by the Aerial Combat Command that high-performance aircraft pilots should not undertake endurance exercise (e.g., running) as part of their physical training regimen [14]. Our experiments also provided a physiological basis for the G-induced loss of consciousness (G-LOC) that occurs in pilots who perform the ‘check six’ maneuver (turning the head to look back over the shoulder for enemy aircraft) during aerial combat. We were the first to demonstrate in humans that side-to-side head rotation inhibits the carotid-cardiac baroreflex that plays an important role in maintaining arterial blood pressure during gravitational stress, and subsequently defends adequate cerebral perfusion [15]. In unprecedented experiments on the physiological adaptation to repeated (chronic) acceleration exposure, our experiments were the first to demonstrate that repeated high-G exposure (i.e., G training) induced cardiovascular and autonomic nervous system adaptations in humans that resulted in significant improvement in maintaining blood pressure and tolerance in subsequent high-G exposures [16]. This work provided the first physiological evidence for the phenomenon of ‘G layoff’, when G tolerance is reduced in pilots because of their ‘layoff’ from active flying. This information proved critical to the development of policy and doctrine when budget cuts forced the Air Force to consider substituting flying hours with training time in simulators. Despite anecdotal comments by pilots that their G tolerance returned to ‘normal’ following two flying exposures after G layoff, our experiments designed to measure various autonomic nervous responses demonstrated that at least three (and perhaps more) high-G training exposures are required to reach maximal G tolerance.","tracks":[{"project":"TEST0","denotations":[{"id":"26587224-209-215-74031","span":{"begin":209,"end":211},"obj":"[\"3297724\"]"},{"id":"26587224-233-239-74032","span":{"begin":600,"end":602},"obj":"[\"8321108\"]"},{"id":"26587224-233-239-74033","span":{"begin":1121,"end":1123},"obj":"[\"9277546\"]"}],"attributes":[{"subj":"26587224-209-215-74031","pred":"source","obj":"TEST0"},{"subj":"26587224-233-239-74032","pred":"source","obj":"TEST0"},{"subj":"26587224-233-239-74033","pred":"source","obj":"TEST0"}]},{"project":"0_colil","denotations":[{"id":"26587224-3297724-74031","span":{"begin":209,"end":211},"obj":"3297724"},{"id":"26587224-8321108-74032","span":{"begin":600,"end":602},"obj":"8321108"},{"id":"26587224-9277546-74033","span":{"begin":1121,"end":1123},"obj":"9277546"}],"attributes":[{"subj":"26587224-3297724-74031","pred":"source","obj":"0_colil"},{"subj":"26587224-8321108-74032","pred":"source","obj":"0_colil"},{"subj":"26587224-9277546-74033","pred":"source","obj":"0_colil"}]},{"project":"2_test","denotations":[{"id":"26587224-3297724-30257649","span":{"begin":209,"end":211},"obj":"3297724"},{"id":"26587224-8321108-30257650","span":{"begin":600,"end":602},"obj":"8321108"},{"id":"26587224-9277546-30257651","span":{"begin":1121,"end":1123},"obj":"9277546"}],"attributes":[{"subj":"26587224-3297724-30257649","pred":"source","obj":"2_test"},{"subj":"26587224-8321108-30257650","pred":"source","obj":"2_test"},{"subj":"26587224-9277546-30257651","pred":"source","obj":"2_test"}]},{"project":"MyTest","denotations":[{"id":"26587224-3297724-30257649","span":{"begin":209,"end":211},"obj":"3297724"},{"id":"26587224-8321108-30257650","span":{"begin":600,"end":602},"obj":"8321108"},{"id":"26587224-9277546-30257651","span":{"begin":1121,"end":1123},"obj":"9277546"}],"namespaces":[{"prefix":"_base","uri":"https://www.uniprot.org/uniprot/testbase"},{"prefix":"UniProtKB","uri":"https://www.uniprot.org/uniprot/"},{"prefix":"uniprot","uri":"https://www.uniprot.org/uniprotkb/"}],"attributes":[{"subj":"26587224-3297724-30257649","pred":"source","obj":"MyTest"},{"subj":"26587224-8321108-30257650","pred":"source","obj":"MyTest"},{"subj":"26587224-9277546-30257651","pred":"source","obj":"MyTest"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"TEST0","color":"#93bcec","default":true},{"id":"0_colil","color":"#d6ec93"},{"id":"2_test","color":"#e793ec"},{"id":"MyTest","color":"#93eccd"}]}]}}