Pavel Tsatsouline's "Power to the People!" shows how to increase core strength dramatically, without "getting big". If you want to be stronger without getting huge, Pavel's high tension technique will get you there. An important side benefit to using his
"hyper-irradiation" method is that it will decrease the likelihood of injury, giving you a firm foundation when lifting.
Pavel Tsatsouline was formerly a physical training instructor for Soviet Special Forces and holds a Masters Degree (or equivalent in the old Soviet education system) in what would probably be called
Kinesiology in the United States. He has been training the U.S. Marines, FBI, DEA, SWAT and other elite units in how to significantly upgrade their strength, power and speed for combat purposes.