The study's aims are twofold: First, to examine physiological correlates of fear of physical activity (PA) and second, to examine correlates between fear of PA and interoceptive abilities in patients with chronic heart failure compared to healthy persons. Patients' fear of PA will be assessed via the "Fear of Activity in Situations - Heart Failure" (FActS-HF) questionnaire. The patient group will be split into two subgroups: One with high fear of PA and the second with low fear of PA based on FActS-HF scores (first control group). Fear of PA will be assessed via an adapted version of FActS-HF in a sample of healthy persons (second control group). Each member of the high-fear-of-PA group will be individually matched with one member of the second control group, based on sex and age. The participants of all three groups undergo the same experimental trials.