What are the acute affects of alcohol intake on exercise?

Alcohol does not reliably increase blood pressure acutely - it can actually cause transient vasodilation - and 'impairs exercise capacity' is not the most accurate primary pairing for its acute exercise-related effects.

Alcohol does not decrease metabolic rate acutely; it provides caloric energy and has variable metabolic effects, and a consistent acute blood pressure increase is not a well-established effect.

Alcohol is a diuretic that increases urine output, leading to dehydration that impairs thermoregulation and cardiovascular efficiency during exercise. Alcohol consumption also increases the risk of cardiac arrhythmias, a phenomenon associated with what is sometimes called holiday heart syndrome. These two effects combine to make acute alcohol intake particularly dangerous relative to exercise performance and safety.

While increased arrhythmia risk is correct, alcohol acutely impairs rather than increases exercise capacity by degrading coordination, reaction time, and cardiovascular efficiency.