@article{oai:aue.repo.nii.ac.jp:00000976,
 author = {Okada, Akiyoshi},
 journal = {愛知教育大学研究報告. 芸術・保健体育・家政・技術科学・創作編},
 month = {Mar},
 note = {text, I investigated age-associated differences in the cardiovascular autonomic responses to dynamic exercise in 12 healthy young (age, 21 ± 1 yr) and 10 healthy elderly (age, 72 ± 5 yr) men. Subjects performed symptom-limited supine ramp ergometer exercise. I assessed autonomic activity through the amplitude of the high-frequency (0.15 to 0.85 Hz) component of the R-R interval fluctuation (RRHF), an index of cardiac vagal activity, and the amplitude of the low-frequency (0.04 to 0.15 Hz) component of mean blood pressure fluctuation (BPLF), an index of vasomotor sympathetic activity. The peak exercise workload and the peak increase in heart rate were lower in the elderly men than in the young men. In the elderly men compared with the young men, the amplitude of RRHF was lower at rest (14 ± 6 vs 42 ± 11 ms, P<0.001), showed a smaller absolute decrease during exercise (11 ± 6 vs 39 ± 13 ms, P<0.05) and withdrew at a lower intensity (50 vs 80%) of peak exercise. At the intensity, similar low values of the RRHF amplitude were found in the two groups (3 ± 1 ms). The resting value of the amplitude of BPLF and its peak increase at the peak exercise were similar in both groups; however, the BPLF amplitude started to increase at a lower exercise intensity in the elderly men than in the young men (40 vs 60% of peak exercise). These findings indicate that in elderly men compared with young men, both withdrawal of cardiac vagal activity and augmentation of sympathetic activity occur earlier during dynamic exercise with increasing workload, suggesting greater dependency on sympathetic mechanisms to generate cardiovascular responses to dynamic exercise in elderly men.},
 pages = {69--78},
 title = {Early dependency on sympathetic drive during dynamic exercise in the elderly},
 volume = {53},
 year = {2004}
}