- BACKGROUND: Heart failure (HF) is a systemic disease which affects mainly older adults. The main symptom of HF is exercise intolerance which in the course of disease can cause limitations in independent functioning. So far no study on the impact of HF on physical fitness in men, regardless of disease severity, has been reported. AIM: To evaluate physical fitness in men with HF independently of age, HF severity, concomitant diseases and pharmacological treatment. METHODS: The study group consisted of 228 men with stable systolic dysfunction (age 60+/-11, left ventricular ejection fraction--LVEF 29+/-9%, NYHA class I/II/III/IV--17/44/35/4%). In order to assess physical fitness the Functional Fitness Test by Rikli and Jones for older adults was used. RESULTS: The level of physical fitness decreased with age. Patients with greater severity of HF had worse aerobic endurance, agility and muscular endurance in comparison with men in NYHA classes I-II. A lower level of agility and dynamic balance was found in patients with higher concentration of NT-proBNP and lower levels of haemoglobin and eGFR. Coexisting atrial fibrillation and diabetes mellitus were associated with decreased physical fitness. No relationship between flexibility and clinical parameters or concomitant diseases was found in the study group. CONCLUSIONS: The most important determinants of physical fitness in men with HF were age and NYHA class. Additional factors which decreased physical fitness were atrial fibrillation and diabetes mellitus. Higher level of NT-proBNP and lower levels of haemoglobin were associated with a reduction of upper body strength and aerobic endurance.