Heart Rate Variability (HRV) in CFS and in FM: a literature study.
A systematic literature study based on 16 case-control studies revealed that FM patients show more HRV aberrances and
indices of increased sympathetic activity (especially in response to stressors), indicative of a dysbalance in the
autonomic nervous system.
In CFS, increased sympathetic activity seems only present at night. Possibly the presence of pain is an important player,
but this and the question of causality can be subject of further research, as well as therapy studies directed to reduced HRV.
One study indeed found positive results on HRV after resistance training in FM.
Meeus M, Goubert D, De Backer F, Struyf F, Hermans L, Iris Coppieters I, De Wandele I, Da Silva H, Calders P.
Heart rate variability in patients with fibromyalgia and patients with chronic fatigue syndrome: a systematic review.
Seminars in Arthritis & Rheumatism: 43(2):279-87. SCI=3.806 (8/29)