Different goals require different approaches because of the individual needs of each situation.

Athletes:

- Can't afford to spend as much time in the gym because of their busy training schedule.

- Must improve physical capacities in the basic movement patterns.

- Need to improve intermuscular coordination as much as possible.

- In most sports, a huge gain in body weight isn't desired (e.g. sports with a weight class limit).

- Athletes will seek mostly neural (CNS) improvements from strength training.

Powerlifters/strength athletes:

- Need to maximize the performance in a few specific lifts (squat, bench, deadlift).

- Require an important contribution from the CNS, tendons, and muscles.

- Need to improve the whole strength-speed spectrum.

- Most powerlifters will seek to increase muscle mass, but not if this increase isn't functional (doesn't bring a proportional strength increase).

- So powerlifters will need to improve both the CNS and muscle tissue while improving coordination in the competition lifts.

Bodybuilders:

- Need to increase muscle mass as much as possible.

- Not only do they want to add muscle, but they must do so in proper balance. If a muscle is out of whack with the rest of the body, this must be addressed.

- While strength is a bonus (as it allows for the use of more weight for the bodybuilding-specific intensity zones), it's not a primary goal.

- So bodybuilders need to improve the muscular system much more than the CNS.

Right off the bat, I think that it's obvious that one single "universal" split can't be adequate for such different situations.

I think we'll all agree that the key to improvements in CNS efficiency is the frequency of practice. It's like with golf, if you want to improve it's much better to hit 50 balls six days a week than to hit 300 balls once a week. Strength and power demonstrations are skills because they're so highly dependant on the CNS. For that reason, the more CNS-oriented your training needs to be, the more frequently you should train a given movement pattern.

For example, athletes rely mostly on the CNS since they're basically training to improve movement patterns and whole-body synergy. For that reason, they should train each movement pattern with a high frequency. Since they're also doing other forms of training, they can't really afford to spend five or six days in the gym. In their case, a whole-body approach three times a week would fit the bill of a high frequency of movement pattern practice, without having to be chained to the gym.

Powerlifters should split their training into "lift days." Basically, on a given workout you focus on a competition lift as well as the muscles involved in that lift.

On the opposite end of the spectrum, bodybuilders need to develop each muscle to the maximum of their capacity while keeping the muscles in proportion. For that purpose, a whole-body approach isn't adequate because it's highly unlikely that an individual will be able to fully develop every single muscle in proper proportion from a whole body split. It would require way too much volume per session; it would end up being counterproductive as far as recovery goes.

Some will argue that it's possible to develop all muscles groups when relying on a limited amount of basic exercises. While this is somewhat true, it isn't a perfect solution for most because compound movements will develop your strongest muscle groups the most, just like in my previous bench press example. When it comes to building the whole body in proportion, relying only on a few select exercises could be problematic.

Another problem with whole body training for bodybuilders is that you'll be much less effective on the latter exercises in the workout because of the accumulated fatigue. This isn't as much of a problem with athletic-type training because there's less metabolic accumulation and less glycogen drainage (because athletes will normally focus on lower rep ranges or explosive movements), so they'll still have plenty of energy for the latter exercises.

However, bodybuilding training (using higher rep ranges, supersets, drop sets, short rest intervals, etc.) leads to a greater accumulation of lactic acid and causes more fatigue. So if you're trying to build the body in proportion, this could cause a problem because the muscles being trained last will receive a lesser stimulus for growth. Obviously, this could be countered by rotating the exercise order from workout to workout, but who wants to squat at the end of a whole body workout?

Bodybuilders, more than other athletes, also must live with one harsh reality: not all of their muscle groups will grow at the same pace. This could be due to the fiber composition of the individual muscles, to body structure, or to training experience. So eventually it might be required to perform more work for the lagging muscle groups.

Basically there comes a point where bodybuilders will need to add more exercise variation to build some muscle (or some muscle portion) so that the body is kept in balance. This requires a greater volume of work per muscle group, a thing that can't really be accomplished with whole body training.

That having been said, not everybody falls into one of these three categories. Not all gym rats are powerlifters, athletes, or bodybuilders. In fact, most aren't. I'd say that most serious iron addicts are somewhere between the three animals: they want to look good, be strong, and be athletic. For these individuals, the answer is less white or black: they can opt for several different options.

For these guys, an upper/lower body split like one of these might be ideal:

OPTION 1 (More bodybuilding/muscle oriented)

DAY 1 (Monday): Legs, quad dominant/calves

DAY 2 (Tuesday): Upper body pull

DAY 3 (Thursday): Legs, hips/hams dominant

DAY 4 (Friday): Upper body push

OPTION 2 (More movements oriented)

DAY 1 (Monday): Legs, quad dominant/calves

DAY 2 (Tuesday): Upper body, horizontal push and pull

DAY 3 (Thursday): Legs, hips/hams dominant

DAY 4 (Friday): Upper body, vertical push and pull

Someone who's more into bodybuilding gains, even if he doesn't have plans to compete, could use one of these splits:

OPTION 1

DAY 1 (Monday): Shoulders/triceps

DAY 2 (Tuesday): Quads/hams/calves

DAY 3 (Thursday): Back/rear delts

DAY 4 (Friday): Chest/biceps

OPTION 2

DAY 1 (Monday): Quads/hams/calves

DAY 2 (Tuesday): Chest/Back

DAY 3 (Thursday): Shoulders/rear delts

DAY 4 (Friday): Biceps/triceps

Basically, the more volume you use per muscle group, the less frequently a muscle group can be trained.

Solid information taken from the great debate at T-Nation....