D in the morning, during this time you have been inactive for the past (hopefully) 8-9 hours or else you will be sleep deprived and your body is not at its 100%. Sleep deprivation could cause many disadvantages to your morning exercise and the day ahead. The most important is to start well rested and get at it with good stretching exercises and you will give your best to a better you. The hardest part about exercising in the morning is the mental battle that you will face with your "lazy self". The "lazy self" will keep pushing you to sleep more or eat that wonderful slice of cake from breakfast but you need to be able to battle this mental state and push towards a better you that only thinks of a healthier state.
Fainting is a common symptom of heat stroke. The reason this happens to many people is the lack of fatigue. The best remedy is to keep yourself hydrated and have proper rest.
I hope it helps, Regards.
