Originally Posted by 3half
If you weightlift, you probably already know this, but here goes. Doing less set/reps with higher weight builds muscle. Otherwise known as "maxing out". On the other hand, doing more sets/reps with less weight tones and defines muscles. This is what your looking to do.
There is a slight misconception here. Lifting very low reps, very high weight or "maxing out" is best for strength development (1-4 reps). Lifting for low - medium reps (5-12) is best for building muscle.
For building muscle, this is only true in the presence of a surplus of calories and protein. In the absence of such, it is the most effective for maintaing muscle. (Not losing it due to diet)
To maximize "tone" or definition, you need to remove fat. The more muscle you retain while removing fat, the bigger and more defined the muscle will be. Consider this the difference between a skinny teenager with "abs" and a professional bodybuilder.
So, outside of injury recovery, or sports training, there is no aesthetic purpose for high reps. It does NOT make you more toned.
Instead, maintain heavy lifts (not maxing out, but lower reps < 12). This is true for both men and women. From there, eat responsibly and get your cardio in. Diet will be the determining factor.
If you do not know how to lift with proper form, and are not under the direct supervision of someone who does; please do not attempt to max out any lifts. You WILL hurt yourself, and that will make getting in better shape all the harder.