NASA, Ames Research Center (1970–1982)
My undergraduate and graduate studies in systemic integrative exercise and environmental physiology prepared me well for the unique opportunities to participate in various human experiments in the area of extreme physiology and medicine. My initial research experience began in 1970 in the role of a volunteer subject in exercise experiments (Fig. 1) conducted in the Laboratory of Human Environmental Physiology at NASA’s Ames Research Center under the directorship of Dr. John Greenleaf in collaboration with my undergraduate advisor at San Jose State University, Dr. James Bosco. I also had the opportunity to participate as a volunteer subject in studies to test early NASA prototypes of liquid-cooling garments that were developed as a countermeasure to avoid the serious operational issue of hyperthermia associated with extra-vehicular activity (EVA) space walks (Fig. 2). This experience became the backbone of my motivation to study human physiology in extreme conditions and led to my participation as a volunteer assistant lab staff in experiments designed to describe the acute and chronic physiological responses and adaptations to exercise in environments of hypoxia, heat stress, and bed rest as a simulation of microgravity. My subsequent enrollment to graduate school to pursue my doctoral degree in physiology at the University of California at Davis under the mentorship of Dr. Edmund Bernauer provided an opportunity to continue human environmental research in Dr. Greenleaf’s lab. My subsequent research on the study of mechanisms underlying the expansion of plasma and blood volume with acute and repeated exercise and heat exposure formed the basis for my doctoral dissertation. My dissertation research demonstrated that both physical exercise and body heat contributed separately and additively to optimal expansion of plasma volume [1].
Fig. 1 Expired air collection from subject Convertino into a tissot tank during metabolic experiments conducted in the summer of 1970 at the Laboratory of Human Environmental Physiology at NASA’s Ames Research Center
Fig. 2 Human volunteer Convertino donning an early prototype for testing of a liquid cooling garment (LCG) developed for use by astronauts for thermoregulation during extravehicular activities in the summer of 1978 at NASA’s Ames Research Center. The late Dr. Alan Chambers, former Chief of the Man-Vehicle Systems Research Division and Director of Space Research, is instrumenting Convertino
After completing my doctoral degree, I accepted a position as a Research Associate in the Cardiology Division at the Stanford University School of Medicine. In this position, I was able to work under the mentorship of Dr. Harold Sandler, chief of the Biomedical Research Division at NASA-Ames on the study of physiological adaptation to varying gravity environments, with development of exercise training and countermeasures for astronauts. The collaboration with Dr. Norman Shumway who performed the first cardiac and heart–lung transplants at Stanford University led to the novel water-immersion experiments that taught us that excretion of antidiuretic hormone due to enlargement of the heart did not require afferent nerve signals from cardiac receptors in the control of spaceflight-induced diuresis [2]. The Stanford–NASA collaboration also provided the opportunity to conduct multiple research studies on the effect of prolonged exposure to bed rest (a ground model used to simulate the physiological effects of microgravity) on the physical work capacity of astronauts. These studies, conducted in the bed rest facility at NASA-Ames under the directorship of Dee O’Hara, were the first to involve comparisons of men and women across a large spectrum of age from 19 to 65 years [3]. The highlight of these investigations was my opportunity to be the lead exercise physiologist in the first US–Soviet collaboration bed rest study in the summer of 1979.