A multivitamin. It's not exotic, but it is a must for everyone who doesn't get enough fruits and vegetables. (That's you, and up to 80% of other men.) Rather than megadoses of nutrients, look for one pill that provides 100% of your daily requirements for as many different vitamins and minerals as possible. (Amounts exceeding 100% are generally a waste.) And make sure you buy a men's formula, without extra iron. Excess levels of the mineral could increase your risk of heart disease (a condition called hemachromatosis), says Doug Kalman, M.S., R.D., director of clinical research at Miami Research Associates.
Protein powder. You can get plenty of protein in your diet, but protein powder has other advantages: It's convenient and generally lower in calories than an entire "high protein" meal. Drinking a protein shake after every workout speeds muscle recovery and supplies your body with the amino acids needed for muscle growth. There are two widely used proteins: whey and casein. Whey is absorbed more quickly by the body, while casein is digested slowly-providing the body with a longer-lasting supply of muscle-building nutrients. (That's why many researchers recommend taking a mixture of the two to help sustain the release of amino acids into the blood for as long as possible.)
Creatine. This synthetic version of an energy source produced naturally in the body is stored in the muscles for use during exercise. And it works! Multiple studies show that creatine does help speed recovery and the growth of lean-muscle mass after a workout. Manufacturers used to agree that new creatine users should start with a weeklong "loading phase" of 20 grams per day; however, recent research shows that this isn't necessary, according to Chris Mohr, Ph.D., R.D., adjunct professor of nutrition at the University of Louisville. You can start taking creatine at the normal dose of three to five grams per day after a workout. (You can even mix it directly with your protein powder.)
Green tea. If we haven't beaten you over the head with the findings enough in the last year, here's a recap: Green tea fights fat. Animals who are given the extract in studies gain less weight and burn substantially more fat than animals getting a placebo. You can drink the tea-experts ideally recommend about eight glasses a day-or go the easier route and just take a supplement. (Aim for 90 milligrams three times daily.)
Fish oil. Most guys in their 20s and 30s aren't thinking about their hearts. But if you have a family history of heart disease, you ought to start thinking about fish oil, the best protection available against the disease. Experts recommend taking at least one to two grams a day. Be aware: This is not the time to scrimp and save money. Cheap fish-oil supplements taste like fish and can leave you hiccuping herring all day. Higherquality brands are more expensive, but they have much less of a fishy taste. There are literally thousands of pills you could be taking at any one time. Forget them. These are the five every guy should be taking in order to fight disease, counteract bad genes, and simply live as long as possible.