It is frequently asked if one should undertake cardio training on an empty stomach. The answer to this is no. If your body has no food in it and has easily sourced energy, your body will actually start to take energy from your muscular tissues, so in the unlikely event of you wanting to shed muscles, I wouldn't recommend doing cardio on an empty stomach. Plan a light meal about HALF AN HOUR before your training. This will be sound advice in your entire exercise regime.