Get up early, get out there and exercise in the fresh morning air - wisdom that has been handed down through generations. But perhaps, it may be safer to snuggle down and stay in bed until a bit later, at least during winter mornings in Bengaluru. An ongoing study by scientists at the Indian Institute of Science in Bengaluru has shown that air quality is actually at its worst early in the morning - between 5.30 and 7.30am.