Specialization VS Transfer
One of the primary areas of confusion in strength and conditioning programming is specialization VS transfer. Transfer is the degree to which strength and conditioning in the gym transfers to the field of play or to real life activities. Specialization is to focus your training on a specific lift, or a few specific lifts. A powerlifting program would be an example of specialization, due to its focus on the bench press, squat and deadlift. Dan John has said that specialization comes with a cost. The primary cost is transfer. When you think about sports activities or every day life activities, they are not isolated to a few angles, ranges of motion or movement speeds. There is no way that 3-4 lifts can train for all of the possibilities. The way to get transfer is variety. However, there is a trade off. Too much variety can compromise progress towards developing strength and power. If you have too much variety, you never perform a lift often enough to really progress. You can’t really increase you bench press optimally if you are only bench pressing once per month.
If you are a strength sport athlete (powerlifter, Olympic lifter) you do not care about transfer. Your goal is lifting more weight, in a few key lifts. Specialization is probably going to be your best bet. But what about those who are using the weight room to improve performance outside of the weight room? You need MODERATE variety.
Everyone who has trained with weights for a significant amount of time is familiar with a specific phenomenon. When you first incorporate a new lift, you progress rapidly before stalling. You can usually make good progress for about 3-6 weeks.
These simple observations have lead some strength coaches to develop a concept called conjugate periodization. A part of the conjugate periodization concept is to introduce a lift, and perform that lift for 3-6 weeks before switching to another. This provides moderate variation, while providing enough consistency to improve. It also allows an athlete to take advantage of the quick gains after introducing a lift, continuously, because you are swapping lifts every 3-6 weeks.
For example, you might choose the bench press for your primary “push” exercise and deadlifts for you primary “hip hinge” exercise initially. After 4 weeks you could switch to push press and cleans.
In summary, variety improves transfer but too much compromises strength and power gains. Specialization drives up specific lifts but compromises transfer. A moderate amount of variety is probably best for non-strength athletes.