Adding sauna after training improved VO2max and systolic blood pressure compared with exercise alone in one randomized trial. Researchers in Finland followed 47 sedentary adults with at least one cardiovascular risk factor. Their average age was 49. For 8 weeks, participants completed 3 exercise sessions per week. One group stopped after exercise; the other added 15 minutes of sauna after each session. The comparison gives us a useful measure of the additional effect. The exercise-plus-sauna group gained 2.7 mL/kg/min more VO2max than the exercise-only group. Its systolic blood pressure fell by an additional 8 mmHg, and total cholesterol also decreased. Those results fit the physiology. Heat sends more blood toward the skin. The increased flow creates shear stress along the vessel wall, which stimulates the endothelium. Exercise uses that same vascular pathway while also loading muscles, bones, balance, coordination and aerobic capacity. In daily life, exercise supplies the broad training stimulus, and heat may then extend part of the haemodynamic work. Before training, heat can cause dehydration and fatigue, which may lower the quality of the session. This trial also has clear boundaries. It included 47 people and measured changes over 8 weeks. It cannot tell us what happens over 20 years, and it does not turn sauna into a treatment for every person with high blood pressure. The observational Finnish data require the same restraint. Frequent sauna use was associated with lower cardiovascular mortality over more than 20 years, but those cohorts do not establish causality. In practice, complete the exercise first, then consider heat if it suits your health and schedule. Sauna never replaces physical activity, does not count toward the 150 weekly minutes, and does not remove the need to treat hypertension. Anyone with heart disease should discuss regular heat exposure with a doctor.