Fitness and Exercise: Worst Things to Eat or Drink Before a Workout

These might seem like a good idea before you hit the gym, but there's no clear definition of what they really are. Check the labels -- both kinds can have lots of sugar. If they do, your body will burn through that fast, and you may not get much else.

Your body needs fiber, but not before a workout. Vegetables like broccoli, Brussels sprouts, or cauliflower can be hard to digest and could make exercising uncomfortable. Stick with veggies that are easier on your system, like well-cooked asparagus or potatoes.

Not all fats are bad for you. But foods that have a lot of any fat can be a bad idea if you’re about to be active. Things like red meat make your body work hard to change their fat to energy. That can make you tired before you even get started.

As with protein bars, you'll need to read the label carefully. Certain brands can be surprisingly high in sugar and fat, neither of which is good for your workout. And if you don’t digest dairy easily, a stop at the gym can make things worse.

These sound great in theory as a way to hydrate and get nutrients at the same time. But in practice, they can be less than ideal. Some are packed with sugar and will give you only a short burst of energy before the dreaded "crash." And depending on what’s in it, a single smoothie can have as many as 800 calories.

This seed has all sorts of potential health benefits -- some people use it to try to ease constipation or lower their cholesterol level. But it's high in fiber and fatty acids, which aren’t what you want before a workout. So when adding it to your diet, pay attention to when you have it.

It might be tempting, but skip the drive-through on the way to the gym. Chances are, you’ll feel uncomfortably full, and the fat and sugar in most fast food items will keep you from getting the most out of your workout.

Like smoothies, these might seem like a natural pre-workout boost, but they have lots of things that can make you jittery and raise your heart rate and blood pressure. It’s better to steer clear of energy drinks until after your workout.

This can give you the "daily double" of sugar and caffeine. You'll get a quickly disappearing rush of energy and lots of calories, along with all the issues caffeine can cause. It doesn’t give you any nutritional value and isn’t a good choice for hydration.

While plenty of things aren't great for pre-workout snacks, not eating might be just as bad, even if you’re trying to lose weight. Your body needs fuel to keep you going strong, but it needs the right fuel at the right time.

Experts say the best way to go is a snack that's a combination of carbs (to give you fuel) and protein (to get your body ready to build and repair muscles). Some ideas include a banana and some peanut butter with crackers, a handful of nuts and raisins, or a hardboiled egg.

Even the right choice of pre-workout meal or snack isn't a good idea if you have it right before you're active. Your digestive system will be competing with the rest of your body for blood and oxygen, which are important for building and repairing muscles. Everyone is different, but a buffer of 1 to 3 hours does the trick for most people.