glycogen and Paraplegia

Seven wheelchair-dependent endurance athletes (5 males, 2 females, mean age = 27 years, mean VO2 max = 2.01 1/min) consented to maximal and submaximal (SM) testing on a wheelchair ergometer for the purpose of determining aerobic capacity, plasma substrate concentration, and muscle glycogen utilization during prolonged exercise. Results from an initial graded maximal test were used to determine exercise intensity levels during a subsequent 1-h submaximal endurance ride on the wheelchair ergometer (60%-70% VO2 max). Muscle biopsy samples (N = 5) were taken from the M. deltoideus (anterior head) before and after the submaximal exercise. Hematocrit (Hct), hemoglobin (Hb), glycerol (G), glucose (Glu), and free fatty acids (FFA) measured from venous blood taken before, midway, and at completion of the SM test demonstrated changes in plasma volume and substrate level similar to those of other athletes observed while running on a treadmill or exercising on a cycle ergometer. Type I fibers were characteristically depleted of glycogen, as measured by PAS stain, as a result of the SM endurance ride. Pre-exercise glycogen values were similar among subjects (means = 92.46 mmol X kg-1 +/- SEM 1.8) while muscle glycogen utilization varied from 17.4 to 46.6 mmol X kg-1. These findings indicate that physiologic response patterns of the upper arm muscles of trained wheelchair athletes during acute endurance exercise correspond to those observed in the leg muscles of able-bodied endurance athletes.

Topics: Adult; Female; Glycogen; Humans; Male; Muscles; Oxygen Consumption; Paraplegia; Physical Endurance; Physical Exertion; Physical Fitness; Sports Medicine

In the past three decades, wheelchair sports have become an international reality. Disabled athletes are exercising their right to accept the challenges and risks taken by able-bodied athletes. Marathon racing over a 26-mile, 385-yard course is the latest and most strenuous of the wheelchair athletic events. The small amount of available research data on wheelchair sports has been summarized, as well as some relevant data from exercise physiology studies on able-bodied subjects. Physicians and other health professionals who work with disabled people should be knowledgeable about the risks and benefits of wheelchair sports. Much more basic research is needed to improve the safety, training techniques, and performance of wheelchair athletes.

Topics: Athletic Injuries; Body Weight; Capillaries; Dehydration; Energy Metabolism; Female; Glycogen; Humans; Hypothermia; Male; Muscles; Oxygen Consumption; Paraplegia; Sports; Sports Medicine; Wheelchairs

Topics: Adult; Albumins; Amino Acids; Blood Proteins; DNA; Glycogen; Hemoglobins; Hexosamines; Humans; Middle Aged; Paraplegia; Pressure Ulcer; Protein Deficiency; Proteins; RNA; Water; Wound Healing