Tips from a recent Men’s Health article:

  • Consume enough calories - it takes calories to form antibodies to fend of germs. If you're consuming the right amount calories, your body weight shouldn't move more than 1-2 pounds per week.
  • Make sure you're getting enough rest - insufficient sleep depresses the immune system. Avoid excessive caffeine.
  • Take 5-15 grams of L-Glutamine (they recommended GNC Pro Performance) after a workout - good for your white blood cells.
  • Make sure you're not exercising too much and giving your body time to repair itself.
  • Drink lots of water
  • Get a flu shot, especially if you have respiratory problems, heart problems or asthma.