She ignited a culture war with a jeans advert. Now she has delivered a knockout performance as boxer Christy Martin. Sweeney talks about taking punches in the ring – and in the media She ignited a culture war with a jeans advert. Now she has delivered a knockout performance as boxer Christy Martin. Sweeney talks about taking punches in the ring – and in the media T here was much blood and sweat – but few tears – involved in Sydney Sweeney’s transformation into Christy Martin. David Michôd’s