Mayo Clinic
A warmup gradually revs up your cardiovascular system by raising your body temperature and increasing blood flow to your muscles. Warming up may also help reduce muscle soreness and lessen your risk of injury. Cooling down after your workout allows for a gradual recovery of preexercise heart rate and blood pressure.
Egypt Today
The benefits to cooling down are :
Regulating your heart rate.
Reducing the build-up of lactic acid.
Preventing injuries Like warming up, cooling down after exercises help prevent injuries such as muscle tears. ...
Body restoration.
Stress relief and relaxation
These aren't mine, but they're both from trusted sources.