PROBLEM: Loss of lean body mass. Starting around age 35, you naturally lose about 5 percent of your muscle mass every decade. If you don't prevent this loss of metabolically active tissue, you'll burn fewer calories—and start putting on flab.
SOLUTION: Do the Forever Workout and ensure you get the greatest benefit with proper nutritional support—about 150 to 200 percent of the RDA for protein—to maximize muscle building. Aim for 20 to 30 grams of protein—the amount found in three to four ounces of turkey or three to four eggs—a half-hour before resistance training. Another great source is whey protein powder, which is concentrated, convenient, and high in essential branched-chain amino acids. Add it to milk or yogurt for a good protein mix. (The carbohydrate found in milk and yogurt also elicits a response from muscle-building insulin.)

PROBLEM: Poor recovery. To get stronger, your body must recoup properly between workouts, a process that naturally gets slower with age.
SOLUTION: Refuel quickly and with the right foods. For recovery eating, you need carbohydrates, with protein playing a supporting role. The best mix is about half a gram of carbs per pound of body weight, and about 15 to 20 grams of protein. For a 165-pound man, these amounts are found in half a cup of granola and 12 ounces of yogurt or one high-protein energy bar and a glass of juice. Rehydrate at the rate of 20 to 24 ounces of fluid for every pound lost during exercise. Water and sports drinks are ideal; add brewed black or green tea during the day for an antioxidant boost.

PROBLEM: Decreasing bone mass and strength.
SOLUTION: Get adequate amounts of calcium, vitamin D, and magnesium. Consume 1,000 to 1,200 milligrams (or up to 1,500 for women) of calcium daily, the amount in three to four cups of milk. If you don't like milk, other good calcium sources include yogurt, cheese, kale, bok choy, and broccoli. Calcium-fortified foods, like orange juice, also count. Most of us get enough vitamin D—essential for calcium absorption—from 20 minutes of sunlight. Spend all your daylight hours in the office? Get a new job! Or add the following to your diet: fatty fish (like salmon), egg yolk, vitamin D–fortified dairy milk, soy milk, and cereals. Magnesium, which helps bone formation, is found in whole grains, avocados, almonds, and dark green leafy vegetables (the latter are also a source of vitamin K, which is needed for bone strength).

PROBLEM: Frequent illness, which limits your workout time.
SOLUTION: Keep your immune system on high alert with colorful fruits and vegetables, nuts, and seeds—all excellent sources of antioxidants like vitamin C, carotenoids, and bioflavonoids. Variety is key, but consume plenty of berries—they're like little antioxidant bombs. Fresh produce also contains folic acid, which promotes heart health. Round out your disease-fighting diet with plenty of whole-grain varieties of rice, pasta, and bread, plus fiber-rich foods like beans and oatmeal.

PROBLEM: Internal inflammation that could lead to chronic illness.
SOLUTION: Consume healthy fats. Omega-3 fatty acids, particularly the form found in fish and fish oil, effectively reduce or prevent internal inflammation. Aim for 1,500 milligrams daily, the amount in three ounces of salmon or one to two fish-oil pills. Other sources of omega-3's include canola oil, walnuts, flaxseed, and wheat germ. Extra-virgin olive oil also has anti-inflammatory properties.

FAST FOOD Six-time Hawaiian Ironman champion Ken Glah and his wife, Jan Wanklyn, herself a five-time Ironman champ, recommend this quick, nutritious recipe

ORZO SALAD
2 cups orzo, cooked
6 chopped shallots
1 cup chopped red, green, and yellow bell peppers
1 cup chopped mushrooms
8 oz yellow corn
Add sun-dried tomatoes, chopped carrots, and raisins to taste; serve with chicken or salmon for a protein boost.

DRESSING
Two parts olive oil to one part soy sauce
1 tbsp honey
3–4 chopped garlic cloves
Juice of two lemons
Mix well.