So how many days a week do you need to lift weights?

And should you train your entire body during each workout, or split your workouts up and train only a few muscle groups each time you go to the gym?

As long as you do your workouts consistently, try to progressively increase the workload done each time, and train with a high level of intensity, both methods can be very effective.

Deciding on one really comes down to how much time you want to spend in the gym, and what other activities outside of weightlifting you plan to participate in.

A whole-body workout done two or three days a week can give you excellent results, and it will only tie up about two to three hours of your week.

On the other hand, body-part routines, while also producing excellent results, can require you to be in the weight room between four and seven days a week, taking up more of your valuable time.

If weightlifting is not your main source of recreation, you may find that lifting nearly every day takes away most of your energy for other activities. For instance, if you like to play sports several days a week, two or three whole-body workouts a week might allow you to save more of your energy for your other activities.

Body-part routines can have their advantages as well. Because the workout is spent on only a few muscle groups, a greater variety of exercises can be done, and the muscle can be trained from more angles.

Also, the higher volume of exercises done per muscle group -- up to a certain point -- can have a positive effect on hypertrophy, or growth.

Body-part routines do need to be well designed and thought out, though. You must carefully plan out the muscles that you're going to train during each workout and the order you're going to train them in throughout the week.

If the same muscle group is trained several days in a row, even if it is not the focus of each workout, it may not allow for enough recovery time to see strength progress. Also, one group of fatigued muscles from Monday's workout, for example, may have a detrimental effect on the muscles you are trying to train on Tuesday.

It generally makes sense to train muscle groups that help each other out on the same day. For example, a good combination would be chest and triceps, or back and biceps. This will allow for the most amount of recovery between workouts for each muscle group, and it will let the muscles work at their "freshest" when they are the focus of that day's workout.

The bottom line is that both whole-body and body-part workouts can be effective.

Once you decide how many days a week you want to spend in the gym and which workout fits your personal preferences, plan on doing it consistently over a long period of time. Do not expect results too quickly; progress takes time.