Snacks to maintain energy level

I am a 56 year old, 130 pound, 5'2 women that does a weight lifting class of 45 minutes (4PM to 4:45PM) and a Cardio Kick Boxing class (5PM to 6PM) every Tuesday, Wednesday, Thursday and Saturday. What is the best type of snack to eat before doing...

these classes to maintain my energy lever thru both classes.

something with a lot of complex carbs, whole grain spaghetti works wonders, we used to eat that an hr or 2 b4 each one of our Football games, keeps constant energy and doesn't let u drop right after its done digesting. other than that something quick on the go would be granola bars, and fig newtons they work wonders also, wouldn't do too many protein bars they're all full of too many preservatives.......

hope this helps