Weight training is an important part of a healthy fitness routine -- it's not just for bodybuilders anymore. And while most people trying to lose weight will stick to cardio, weight training is just as important because it can boost your metabolism and help you tone those flabby bits that you find so embarrassing. But there's a fine line between weight training effectively and wasting your time in the gym. Here are some tips from eDiets:

• Make a specific goal, be it toning, building muscle or increasing energy
• Vary your routine every few weeks.This doesn't mean any big changes -- just change the order of your exercises
• Vary the amount of reps in your sets
  
• Vary the weight you're using
  
• Vary the tempo of reps
• Vary the wait time between sets

For a more in-depth look at the proper way to keep your weight-training routine challenging, check out the full article from eDiets.