lybrate-user, Thanks for the query.
One should not start an exercise or a workout if blood glucose is < 100 mg. Then a pre workout snack of some carb
about 20 to 25 g may be taken. This will help in avoiding post exercise low glucose.
However, if your glucose is high enough, then there is no need for a pre -exercise snack. Plus the workout of 3 t 4 kms walk or cardio (time not mentioned) is not such a vigorous one. Sometimes if the stress
hormone (cortisone) level goes up then there may be higher level of glucose. In such a situation there may not be any need for snack before exercise. Thanks.