Try the windmill exercise and thank me later - it 'targets your obliques from every angle' and improves core strength more than Russian twists

The windmill is an advanced move, but its positive effect on core strength and stability makes it one worth learning how to ...
The Washington Post

'The Windmill Movie,' A Source of Power

The late documentarian and teacher Richard P. Rogers http://www.news.harvard.edu/gazette/2001/07.19/12-rogers.html tried for 25 years to make a movie about his life ...