A Research Roundtable, organized by the American College of Sports Medicine with sponsorship from the National Aeronautics and Space Administration, met in November 1995 to define research strategies for effective exercise countermeasures to weightlessness. Exercise was considered both independently of, and in conjunction with, other therapeutic modalities (e.g., pharmacological, nutritional, hormonal, and growth-related factors) that could prevent or minimize the structural and functional deficits involving skeletal muscle and bone in response to chronic exposure to weightlessness, as well as return to Earth baseline function if a degree of loss is inevitable. Musculoskeletal deficits and countermeasures are described with respect to: 1) muscle and connective tissue atrophy and localized bone loss, 2) reductions in motor performance, 3) potential proneness to injury of hard and soft tissues, and 4) probable interaction between muscle atrophy and cardiovascular alterations that contribute to the postural hypotension observed immediately upon return from space flight. In spite of a variety of countermeasure protocols utilized previously involving largely endurance types of exercise, there is presently no activity-specific countermeasure(s) that adequately prevent or reduce musculoskeletal deficiencies. It seems apparent that countermeasure exercises that have a greater resistance element, as compared to endurance activities, may prove beneficial to the musculoskeletal system. Many questions remain for scientific investigation to identify efficacious countermeasure protocols, which will be imperative with the emerging era of long-term space flight.
Department of Physiology and Biophysics, University of California, Irvine, CA; College of Health and Human Performance, Oregon State University, Corvallis, OR; NASA-Ames Research Center, Moffett Field, CA; Department of Physiological Science, University of California, Los Angeles, CA; Center for Sports Medicine, Pennsylvania State University, University Park, PA; Department of Human Biodynamics, University of California, Berkeley, CA; Department of Medicine, Creighton University, Omaha, NE; Department of Exercise and Sport Science, Oregon State University, Corvallis, OR
Submitted for publication February 1996.
Accepted for publication April 1996.
Address for correspondence: Timothy P. White, Office of the Dean, College of Health and Human Performance, 123 WB, Oregon State University, Corvallis, OR 97331-6802.