Question about Strength Training

I was wondering....

Is it better to use lighter weights and do more reps or use heavier weights but do less reps???

At the gym, I'll use 5lb, 7.5lb or 10lb weights while I do strength training.  It always gives me a good workout.  But at home the heaviest weight I have are 4lbs, so I use those but just do more reps.

Which is better? I am still getting a good workout if I use one method over the other?  Thanks for the help!!  

Heavier weights/lower reps (by low, I mean at most 12) is better. Doing lighter weights for more reps won't challenge your muscles the same way - though it will help some with muscle endurance.

No question about it - heavier weights.  I suspect that, like most women, you are a lot stronger than you realize. Probably even the weights you use at the gym aren't heavy enough to challenge you once you learn to use lower rep ranges in your workouts.

As Amethystgirl said, rep range for strenth and muscle definition (aka "toning") is best accomplished with a weight that you can only lift 8-12 times.

In addition, I'd reccommend that you focus on large muscle groups with compound movements.  In other workds, not endless bicep curls or tricep kickbacks but instead  building outward from the larger muscles of your upper body.  For example, chest press will work your pec muscles, but also triceps. Same with lat pulldows or rows...they also exercise the biceps. Since these are larger, stronger muscle groups, you'll find that you can use a lot more weight and have better results, too!

There are lots of good online resources for weight training programs that will shape your entire body. Oh, and don't be afraid of "bulking up" - women don't have the hormones that would make them get huge from lifting weights.  Instead you'll just look sleek!

Good luck!