To test the hypothesis that autonomic modulation after resistance exercise (RE) would be reduced in women with fibromyalgia (FM) compared with controls.
Before-after trial.
Testing occurred in a university setting.
Women with FM (n=9) and healthy controls (n=9) underwent testing before (pre) and 20 minutes after (post) RE.
Not applicable.
Normalized low-frequency (LFnu) and normalized high-frequency (HFnu) oscillations and the LFnu/HFnu ratio were indicative of sympathetic modulation, parasympathetic modulation, and sympathovagal balance, respectively. Baroreceptor reflex sensitivity (BRS) was also measured.
Variables were similar in both groups at rest. HFnu decreased in controls (pre, 55.0+/-4.2%; post, 35.0+/-4.7%; P<.05) and increased in women with FM (pre, 57.0+/-5.7%; post, 63.2+/-4.6%; P<.05). LFnu increased in controls (pre, 43.3+/-4.4%; post, 63.2+/-4.8%; P<.05) and decreased in women with FM (pre, 41.8+/-5.6%; post, 35.6+/-4.7%; P<.05). The LFnu/HFnu ratio increased in controls (pre, 0.89+/-0.17; post, 2.43+/-0.64; P<.05) with no change in women with FM (pre, 0.90+/-0.22; post, 0.64+/-0.13; P=.13). BRS decreased in controls (pre, 8.78+/-1.42 ms/mmHg; post, 5.49+/-0.66 ms/mmHg; P<.05), but not in women with FM (pre, 5.91+/-1.22 ms/mmHg; post, 9.23+/-2.4 ms/mmHg; P=.16).
After acute RE, women with FM responded differently from controls, demonstrated by lower sympathetic and higher vagal modulation without altering BRS. These postexercise responses may be attributed to the altered autonomic responsiveness to physiologic stress that characterizes FM.