Here's the lowdown on what you should consume before a workout:
Cardio ONLY workouts (44 min or less): Have a few extra minutes to squeeze in a quick HIIT workout or even just go for a power walk? If you are only doing a cardio workout, you should have a 50-100 calorie source of quick digesting carbohydrates to rev up your metabolism and keep your body burning fat throughout your workout.
Cardio ONLY workouts (45 min +): Hitting the streets for a hardcore run? (I would consider anything over 3 miles hard core - I am not a runner! Yet!) You should have any where from 100-150 calories of a quick digesting and a slower digesting carbohydrate source. Skip the protein source until after your workout.
Weight Training/Lifting Session: Planning to pump iron before breakfast? Not so fast! Make sure you eat 150-200 calories of a quick digesting carb (such as one 30 cal rice cake), slower digesting carbs and a lean protein source. Don't waste your hard work - you want to build those muscles!
Here is a quick list of snacks you can use to create your pre-workout snack. Please note: there are many other snacks you can choose from - I included only these as they are quick to prepare, travel well and tend to cause the least amount of stomach issues once you are working out. You can definitely add to this list!
Quick Digesting Carbs
Low Sodium White Rice Cake - approximately 30 calories per rice cake
Banana - approximately 105 calories per medium (7 in) banana
Green Apple - approximately 72 calories per medium (3 in in diameter) apple
Slower Digesting Carbs
Low Sodium Brown Rice Cake - approximately 50 calories per rice cake
Oats (Quick Cooking, Steel Cut or Old Fashioned) - approximately 80 calories in 1/4 Cup of oats
Sweet Potato - approximately 90 calories in 1/2 Cup of baked sweet potato
Brown Rice - approximately 54 calories per 1/4 Cup of cooked brown rice
Lean Protein Source
Protein Shake - this is the sometimes the most quickest way to get your calories if you are in a hurry! Calories will vary depending on your brand of protein powder.
Scrambled/Boiled Egg White - approximately 17 calories per large egg white (4g of protein per egg)
Fresh, Raw Peanut Butter - I do not recommend that you consume this if you are doing cardio. It is somewhat harsh on the stomach. Approximately 105 calories per TBSP.
Raw Almonds - 10 raw almonds are approximately 70 calories.
What should you eat after a workout?
That's pretty simple - a 100-200 calorie snack consisting of a lean protein source and a quick digesting carbohydrate source. The carbohydrates will help your body to digest and use the protein source that you have consumed and repair your muscles (this is how you build muscle. Tear it down to build it up!). It is IMPERATIVE that you eat within 30 minutes of a workout for optimal results!!
Hope that answers your questions!