If I'm working out in the evening (an hour of cardio at, say, 8pm-9pm), should I have dinner before or afterwards? What effects will it have on a) my workout if I eat beforehand and b) my recovery if I eat afterwards?
(If I were to eat before the workout, then I'd top up afterwards with a recovery drink of some sort – usually skimmed milk, yoghurt, blended banana, and Nesquick.)
In terms of overall nutrition, when you eat is not nearly as important as how much you eat (and what you eat).
But in practical terms, it may make a big difference:
as mentioned in the article I linked to, if you skip meals/wait until you're very hungry, it may make you more likely to overeat later. That's more a problem of psychology than nutrition, though.
this varies a lot per person, but for myself I have a very difficult time working out soon after eating, with all of that stuff sloshing around in my stomach and full feeling. I prefer to eat very soon after a workout.
there are some indications that the body may be "primed" to more readily absorb carbohydrates post-workout and consequently help prevent delayed-onset muscle soreness.
You mentioned that your workout is fairly late in the evening. If you were to wait to eat until after that workout, that's likely a very long stretch between lunch and dinnertime. You could either shift your lunch a little later, or perhaps have a light snack around 4-5 p.m. just so you have a little fuel for your workout.
The day before you workout you should eat some kind of long chain carbohydrate (such as pasta) for energy and right before you workout I'd suggest something like a cliff bar or power-bar and then afterward I would always drink chocolate milk, with the healthiest milk in it that you can stand, that is proven to replace electrolytes even better than gatorade!
There is a simple answer to your question. You should never eat right before the workout because you can be sick during the workout, and you will feel "heavy", which is not good. So, try to follow this rule: eat 2 hours before your workout. This way your body will have enough energy to burn and you will feel good during your workout. Also, there is nothing wrong with eating after workout. But, be careful with what you eat and how much you eat! I suggest you eat a salad with boiled eggs, cooked chicken with some beans or whole grain bread with honey and a banana. The thing is, your body will still burn fat after you finish your workout, so eating afterwards will do you no harm.
If you exercise with a full stomach you will have some digestion problems and it will bother you both during exercise and afterwards. Since most of the blood will be directed to your active muscle during exercise, you won't get enough blood circulation to digest the food that means the digestion will not be the primary concern. That is why, eat light meal 2 hours before the exercise than you can have a big meal! after your workout depending on what kind of exercise you are doing.
