What to eat before doing cardio?

I am by no means a professional nutritionist, but I'm just here to share what I've learned works for me.

First of all, it's not good to run or do cardio on an empty stomach, personally if I don't eat anything I feel faint, and dizzy.
If I'm going to go for a run first thing in the morning after I wake up I normally just eat a greek yogurt (Oikos Key Lime is my favourite), munch on like ten or so almonds and give it 20 minutes to digest and head to the gym.

If it's a midday workout, I like to eat a fruit smoothie (blended with frozen blueberries, strawberries, a banana and almond milk) about 1 and a 1/2 hours before I'm going to work out.

And if it's a night workout (like after 6pm), I normally just eat like a light salad with romaine lettuce, tomatoes, cucumbers and a bit of crumbled feta cheese with some light italian dressing about one and a 1/2 hours before I'm going to work out.

Always always always make sure that you give yourself at least an hour and a half to two hours to digest after eating something... Especially if it's heavy (like a hamburger, pizza, etc) trust me you will get cramps and feel like shit.