hello john. you have heard it right. It indeed has multiple benefits. It does not have any side effects but you must be aware of the quantity. 2 glasses are sufficient. Do NOT jog immediately after drinking. Give a gap of 20 mins. For Cardio workout tips you need to be more detailed. thanx.
It is always good to be hydrated before cardio workout, Just keep it to one glass. If you want to maximize your cardio try 1 banana 45 minutes before. This doesn't affect the fat that you are going to burn and will give you the energy you'll need to perfom better. Also try to eat some carbs after, honey, oat etc. This will increase the amount of glycose stored in your liver and give you more endurance the next time you're going to train.
I would wait and drink the water after the workout. too much water before and it could make u throw up