The nutritional supplement industry is an economic juggernaut, one that continues to thrive even during these tougher financial times. Unlike prescription medications, supplements do not have to undergo a vetting process by the FDA, which serves to explain why manufacturers are able to make many unsubstantiated claims with relative impunity.

Does this mean that all supplements are worthless? I certainly wouldn't go as far as to say that. What I would say, however, is that it is wise to speak with a medical professional before taking a supplement to find out: a) If it is safe for you to take it, and b) If it will help you achieve your specific health and fitness goals. In efforts to expedite that conversation (doctors are busy people), at least narrow your options down to supplements that have shown promise in peer-reviewed studies.

Here are 5 of them:

5 - Protein Shake. While it's entirely possible to get enough daily protein from your regular diet, it's sometimes quite difficult to do so. Protein shakes provide you with a convenient and tasty way to get at least 20-25 grams of protein and a substantial amount of amino acids with each serving.

4 - Creatine. The king of muscle-building supplements, clinical tests show that creatine can help increase muscle size and strength, in addition to speeding up recovery time after a workout.

3 - Multivitamin. Many people don't get their RDA of vitamins and minerals. A simple fix is a multi. Be sure to buy a 'complete' multivitamin; such as GNC's Mega Men, Ultra Mega for Women or even Centrum.

2 - Green Tea. I know - tea isn't exactly the coolest thing to drink. Still, you're going to have to suck it up and drink it down if you want to obtain the benefits of its natural antioxidants and fat-burning properties.

1 - Fish Oil. It's certainly no mystery by now that Omega-3 fatty acids are extremely important to help stave off heart disease and a myriad of other maladies, which is why adding fish oil to your diet may be a good idea.