Effectiveness of Daily loading of artificial gravity and ergometric exercise as a countermeasure Iwase S, Sugenoya J, Nishimura N, Sato M, Shimizu Y, Konikowska D, Takada H, Takada M, Mano T, Ishida K, Akima H, Hirayanagi K, Katayama K, Ish
- Paper number
IAC-09.A1.2.2
- Author
Prof. Satoshi Iwase, Aich Medical University, Japan
- Year
2009
- Abstract
Effectiveness of centrifuge-induced artificial gravity and ergometric exercise as a countermeasure to space deconditioning, induced by 20 days of head-down bedrest., was examined in 12 healthy men in 2006, and 8 healthy men in 2007. Bedrest was performed with 2300 kcal of diet, and water intake was encouraged more than the urine volume in a previous day. The protocol for artificial gravity with ergometric exercise was adopted, with 1.6 G of artificial gravity at heart level and 60 W of exercise every day (ECM) and alternate day (ACM). The load was continued until 30 min cumulative total load time. Gravity was stepped up by 0.2 G or exercise load was stepped up by 15 W alternately when the subject endured the load for 5 min. Gravity tolerance was examined with centrifuge by anti-G score. RESULTS: 1) Orthostatic tolerance: ECM could suppress the bedrest-induced orthostatic intolerance. 2) Circulating blood volume: ECM showed no significant difference in the circulating blood volume, whereas CONT decreased by 5%. ACM decreased the circulating blood volume by 4%. 3) Sympathetic response to tilt: Tilt-induced excitation was preserved by ECM and ACM, and there were no significant difference. 4) Physical fitness: VO2max was increased in ECM, but was decreased in CONT in 2006. Endurance time to exhaustion (ET) was elongated in ECM, but was shortened in CONT, however, ACM decreased in VO2max and ET. 5) Echocardiographic Cardiac dimension: End diastolic and systolic volume was decreased in CONT, while it was increased in ECM. Ejection fraction and fractional shortening were increased in CONT, and decreased in ECM. These indicate enhanced cardiac function in CM, and reduced in CONT, however, ACM showed no constant results. 6) Myatrophy: With MRI, cross section of the quadriceps femoris was revealed to be maintained in ECM, whereas not in CONT. 7) Bone metabolism: Urinary deoxypyridinoline was significantly suppressed in ECM as compared with CONT while enough suppression was not observed in ACM. 8) Immune and inflammatory system: Increases in WBC and CRP in CONT were suppressed in ECM. We concluded that effectiveness of artificial gravity with ergometric exercise was evidenced in orthostatic tolerance, physical fitness, cardiac function, myatrophy, and bone metabolism as well as immunological impairment and inflammation in ECM, but not in ACM.
- Abstract document
- Manuscript document
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