Fig. 5.

Muscle metaboreflex activation is reduced after exercise training in heart failure with reduced ejection fraction (HFrEF) patients (pretraining, closed triangles; posttraining, open triangles). Muscle sympathetic nerve activity (MSNA) burst frequency in HFrEF during 30% static handgrip (HG) is similar pre- and posttraining but when the metaboreflex is isolated during posthandgrip ischemia (PHGI) is reduced in the 2nd minute of PHGI posttraining. Healthy control subjects (closed circles) have a lower MSNA burst frequency throughout HG and PHGI compared with HFrEF. Data are means ± SE. *P < 0.05; HFrEF (n = 16) pre- vs. posttraining; **P < 0.001 HFrEF vs. controls (n = 18).