Popular among a great deal of athletes, energy bars can help you meet your calorie requirements while also providing a source of protein.

When buying energy bars you want to choose wisely because they can vary considerably in nutritional content. The first thing to check is how much protein the energy bar contains. Very low protein ones are probably not your best bet because they will cause a great increase in blood sugar levels followed by a sharp decrease, thus leaving you feeling fatigued.

Secondly, check out the ingredient listing on the energy bar you are looking at buying. If fructose is a top ingredient, you may want to look elsewhere. The prime reason for this being that fructose is handled by the body differently than glucose is and will not be used to help replenish the muscle's glycogen stores. Since when you are exercising you are using primarily muscle glycogen, consuming this snack choice will not help to fuel your activity - in fact, it could potentially lead to an increase in body fat stores (since after the liver stores are full, any extra fructose is converted directly to fat).

Finally, just make sure that you do in fact need these extra calories. Many will offer up to 400 calories a shot and if you aren't doing a lot of physical activity, this could lead to weight gain. In this case, a lower, more nutrient dense snack like a yogurt and a whole wheat English muffin would be a much better choice.