Final answer:
Beta-blockers are not used to stimulate athletes; they inhibit the effects of adrenaline on the heart to treat cardiovascular diseases and are falsely claimed in the statement as stimulants. These medications lower heart rate and blood pressure, which is the opposite of stimulation.
Step-by-step explanation:
Beta-blockers are not substances that are used to stimulate athletes and prevent fatigue. Therefore, the correct response to the question is 2) False. Beta-blockers actually have the opposite effect; they can inhibit the stimulatory effects of adrenaline on the heart. These drugs, which can be known as sympatholytic drugs, are primarily used to treat cardiovascular diseases. They work by blocking ß-receptors, particularly the ß1-receptor which is associated with increased heart rate and vasoconstriction. For instance, metoprolol and propranolol are common beta-blockers prescribed for conditions like hypertension and congestive heart failure. Their action reduces heart rate and allows blood vessels to dilate, leading to lower blood pressure and reduced work for the heart.
It's important to distinguish between beta-blockers and performance-enhancing drugs like anabolic steroids, as the latter are often misused to boost athletic performance by increasing muscle mass and overall physical capacity, despite their significant health risks and ban by sports organizations.