Detraining from total body exercise ergometry in individuals with spinal cord injury.

This study was designed to investigate the effects of detraining that occurred during an 8 week period of muscular inactivity following a 12 week training program of artificial computerized functional electrical stimulation cycle ergometry (CFES LE) and arm ergometry. Six spinal cord injured male individuals were followed through an 8 week detraining period that was preceded by a 12 week exercise program including CFES LE and arm ergometry. Maximal graded exercise tests were completed and measurements of peak oxygen consumption (VO2), heart rate (HR), ventilation (VE) workload, and creatine kinase were taken. Testing occurred at initial training (0T), after 12 weeks of training (12T), and after 8 weeks of detraining (DT). After the training program, peak VO2 increased significantly from 0.562 +/- 0.126 (0T) to 1.021 +/- 0.247 l/min (12T, P < 0.05). After DT, peak VO2 decreased to 0.791 +/- 0.216 l/min, which was lower than 12T (P < 0.05), yet higher than 0T (P < 0.05). After DT, peak workoad had decreased from 0.675 +/- 0.203 (12T) to 0.32 +/- 0.203 kp (P < 0.05), which was not different than 0T. Creatine kinase levels were significantly lower both at 12T and DT compared to 0T (P < 0.05). In addition, this training program induced linear increases in both VO2 and HR with workload, which were retained after DT. These increases did not reach statistical significance. however. No apparent relationship existed between these values at baseline. There were no significant differences in submaximal or peak HR of VE between the three testing periods. The results indicate that both peripheral muscular adaptations and central distribution adaptations in SCI individuals are partially maintained following 8 weeks of DT from CFES LE and arm ergometry.

Increased endothelin and creatine kinase after electrical stimulation of paraplegic muscle.

The purpose of this study was to assess changes in creatine kinase (CK) and endothelin (ET) in individuals with spinal cord injury (SCI) after computerized functional electrical stimulation leg ergometry (CFES LE). Eight subjects (7 male and 1 female) with complete spinal cord lesions (C7 to L1) completed zero-loaded CFES LE tests at baseline, after 3, 6, and 12 wk of CFES LE training (30 min, 3 times/wk), and also after detraining (DT) (n = 5). Venous blood samples were drawn 24, 48, and 72 h after CFES LE for measurement of ET and CK. The CK response was largest (peak CK) 72 h after baseline tests (28.2 +/- 6.0 to 895.7 +/- 345.9 ktals/l) and was no different from baseline by weeks 3, 6, and 12. After DT, CK was similar before and after CFES LE (153.8 +/- 19.0 and 189.7 +/- 34.5 ktals/l, respectively). CFES LE also significantly increased peak ET after baseline (from 11.7 +/- 1.5 to 18.0 +/- 2.5 pg/ml). During the subsequent training, peak ET remained significantly higher than the baseline value at weeks 3, 6, and 12 (20.2 +/- 1.8, 18.0 +/- 1.1, and 16.9 +/- 2.2 pg/ml, respectively). After DT, peak ET increased significant relationship (r = 0.44) existed between ln peak CK activity and peak ET. In summary, the increase in circulating ET in spinal cord-injured individuals may have implications for baroreceptor function and therefore blood pressure control in SCI. Further research into CFES LE, ET, and baroreceptor function in SCI is warranted.

Exercise in the prevention and management of osteoporosis.

Osteoporosis, characterized by bone loss, is a serious disease affecting millions of elderly women. Current research suggests that regular exercise plays an important role in its prevention. Physical therapists treat many patients who are at risk for developing osteoporosis or who already have the disease. To provide optimum patient care, physical therapists must be knowledgeable about the disease process and the role of exercise in its prevention and management. To meet this need, I have provided a brief overview of the literature on osteoporosis. The structure and dynamic nature of bone are discussed. Factors influencing the development of osteoporosis are identified. Studies dealing with the response of bone to mechanical stress in athletes, in addition to the role of exercise in the prevention of osteoporosis, are reviewed. Finally, recommendations are made for postural training and for extension and weight-bearing exercises in the management of the patient with symptomatic osteoporosis.