NASA Technical Memorandum 112214 Acceleration Tolerance: Effect of Exercise, Acceleration Training; Bed Rest and Weightlessness Deconditioning A Compendium of Research (1950-1996) J. L. Chou, M. A. McKenzie, N. J. Stad, and P. R. Barnes, California State University at San Francisco C. G. R. Jackson, California State University at Fresno F. Ghiasvand and J. E. Greenleaf, Ames Research Center, Moffett Field, California October 1997 National Aeronautics and Space Administration Ames Research Center Moffett Field, California 94035-1000 Contents Page Summary ................................................................................................ iv Introduction ............................................................................................. v Abstracts and Annotations ............................................................................ 1 Additional Selected Bibliography .................................................................... 45 Author Index ............................................................................................ 47 Keyword Index ......................................................................................... 51 iii Summary This compendium includes abstracts and annotations of clinical observations and of more basic studies involving physiological mechanisms concerning interaction of acceleration, training and deconditioning. If the author's abstract or summary was appropriate, it was included. In other cases a more detailed annotation of the paper was prepared under the subheadings Purpose, Methods, Results, and Conclusions. Author and keyword indices are provided, plus an additional selected bibliography of related work and of those papers received after the volume was prepared for publication. This volume includes material published from 1950-1996. iv Introduction The purpose of this compendium is to present summaries of clinical observations and results from more basic studies that help to elucidate physiological mechanisms for control of acceleration tolerance as affected by exercise training and deconditioning. It the author's abstract or summary was appropriate, it was utilized. In some cases a more detailed annotation was provided under the subheadings Purpose, Methods, Results, and Conclusions. This volume includes studies published from 1950 through 1996. Author and keyword indices are provided. The material is listed in alphabetical order by first author and numbered consecutively by abstract number, not page number. We thank our many colleagues who sent us reprints, and apologize to those whose work we have inadvertently overlooked. The authors thank Esther Johnson for valuable technical assistance. J.E.G. 1. Antonutto G, D Linnarsson, CJ Authors' Abstract Sundberg, PE diPrampero. The goal of this study was to provide Artificial gravity in Space: vestibular information for developing means to protect tolerance assessed by human operators from +Gz acceleration. A total of centrifuge spinning on Earth. 36 subjects, aged 20 to 31, participated in the Acta Astronautica 27:71-73. 1992. study. All had been certified fit for Authors' Abstract centrifugation and hypokinesia with head- Artificial gravity created by the astronauts down tilt. Three conditions were run. In the themselves, without any external power first, 10 subjects s_nt 60 hours in supply, by pedalling on a couple of hypokinesia with -60 head-down tilt during counterrotating bicycles along the inner wall the night and -150 during the day. Before of the space module (Twin Bikes System, and after this treatment, subjects' endurance TBS), was previously suggested (Antonutto of +3Gz was assessed for 15 minutes with et al., 1991) to prevent musculo-skeletal and without antigravity device I (AGD-1). decay and cardiovascular deconditioning In the second condition, the effectiveness of during long term space flights. To AGD-1 was tested on 24 subjects before and investigate whether this unusual rotating after a 7-day period of hypokinesia with environment would determine abnormal head-down tilt (-10°). The following stimulations of the vestibular system due to acceleration schedule was used: 2.5- and 3.0- Coriolis cross coupled accelerations, thus G for 5 minutes each, 3.5-, 4.0- and 4.5-G leading to acute motion sickness (AMS), the for 30 minutes each. In the third condition, conditions of a rotating environment were endurance of 6 subjects was measured before reproduced in a human centrifuge. A and after a 7-day period of hypokinesia using cycloergometer was fixed to the arm of the the AGD-2 device and the same acceleration centrifuge, the rotation speed of which was schedule as in condition 2. In all cases, equal to that yielding 1 g at the feet level in acceleration increased at a rate of 0. I-G per the TBS (i.e. ranging from 19 to 21 RPM). second. AGD-I consisted of closely fitting The ergometer position was such that the trousers made of stretch fabric with a high combination of the horizontal and elasticity modulus which could maintain the gravitational acceleration vectors was 1.414 perimeter and volume of the lower body at the inner ear level and was aligned along under exposure to longitudinal G-load. the head to feet axis. Three subjects, AGD-2 was a shortened modification of pedalling at 50 W on a cycloergometer during AGD-1 reaching to the knees. Operator centrifuge's spinning, were asked to move performance was evaluated in condition 3 the head following an AMS' provocation during exposure to acceleration with a control protocol. None of them developed any AMS task using a flight instrument providing symptoms. This supports the look of the information about flight parameters. TBS as tool for avoiding musculo-skeletal Physiological parameters were assessed by and cardiovascular deconditioning during an EKG with tetrapolar chest leads, long term space flights. photoplethysmography of the ear, and a myogram of the femur and abdominal muscles. Subjects were all trained to criterion on the control task before • Asyamolov BF, LI Voronin, VS Panchenko, NV Ulyatovsiy, centrifugation. RA Bondarenko, AV Kaliberdin, SYu Elizarov, VG 3. Balldin UI, K Myhre, PA Tesch, PIokhova, AS Yarov. U Wilheimsen, HT Andersen• Effectiveness of antigravity devices of Isometric abdominal muscle training the chamberless type after 7 days of and G tolerance. hypokinesia with head-down tilt. Aviation, Space, and Environmental Kosmicheskaya Biologiya i Medicine 56: 120-124, 1985. Aviakosmicheskaya Meditsina Authors' Abstract 22:37-40, 1988. Methodsto increaseG toleranceof pilots during submaximal G exposures may be used flying highperformanceaircraftareof vital as indicators of shifts in endurance G importance.Strainingmaneuversto increase tolerance. The procedure may reduce the G toleranceinvolveabdominalmuscles,and need for exhaustive G tolerance tests with highintra-abdominalpressures(IAP) are associated risks and discomfort. recordedduring G exposure. This study was carried out to examine the effects of an 11- 5. Beckman MC, KR Coburn, RM week abdominal muscle training program on Chambers, RE DeForest, WS maximal IAP, G tolerance and muscle Augerson, VG Benson. strength/endurance in 10 fighter pilots. G Physiological changes observed in tolerance was measured in a human human subjects during zero G centrifuge using simulated aerial combat stimulation by immersion in water up maneuvers (ACM). The pilots had a higher to neck level. maximal IAP before training than a control Aerospace Medicine 32:1031-1041, group. G tolerance, maximal lAP, and 1961. maximal peak torque of knee extensors were Authors' Abstract not changed by the training. In contrast, leg Knowledge relative to the effects of muscle endurance increased (p<0.01) and prolonged weightlessness is needed in ratings of local perceived exertion decreased preparing man for space flight. The buoyant (p<0.01). Static endurance of the knee force exerted upon immersed bodies extensors was positively correlated (p<0.05) effectively simulates the weightless state with with G tolerance. It is concluded that the respect to proprioceptive sensory responses present abdominal training program, and perhaps in other ways. An investigation employed in experienced fighter pilots, is not into the physiological effects of immersing sufficient to increase IAP or G tolerance. subjects in water up to neck level was undertaken. It was found that water 4. Balidin UI, P Kuronen, H Rusko, immersion produces an unnatural E. Svensson. physiological situation in that, during Perceived exertion during respiration, the inspired air inflates the lungs submaximal G exposures before and to atmospheric pressure while the external after physical training. pressure against the chest, abdomen, and Aviation, Space, and Environmental legs, due to the water, is greater than Medicine 65:199-203, 1994. atmospheric. This situation is equivalent to Authors' Abstract "negative pressure breathing." Ratings of perceived exertion (RPE) were A series of experiments involving seven registered at submaximal levels in G subjects immersed in water up to neck level endurance tests of a combined strength and for periods of 5 to 23 hours (five subjects for endurance training program in 17 pilots. 12 hours) showed a significant weight loss After 12 months of physical training, the during the period of immersion, which was endurance G tolerance (time to exhaustion explained by the diuresis which occurred. during simulated aerial combat maneuver), Pulmonary volume measurements showed a increased by a mean of