The union of math and sports is a natural one - the winner usually has a number attached to it - fastest speed, greater point accumulation, some combination of both (I still have no clue how diving is scored). With the Winter Olympics approaching, we have another opportunity to tie math to what's happening in today's world. Most of my research, though, found a lot of worksheets and more thematic activities. Then I found the University of Cambridge Math and Sports Millennium Math Project.
This site was originally developed to celebrate the London 2012 Summer Olympics, but still is applicable today. The activities are designed to develop problem solving and mathematical reasoning skills in students age 5 - 18. The site is designed to meet Britain's standards, but each level notes age level, which will help you navigate (Key Stage 3 is ages 11 - 14). Each Key Stage has at least a dozen activities all centered around Olympic events.
Even though the site was developed off of the British academic framework, the activities clearly tie to the Common Core. Students must make sense of the challenge before them, and devise arguments for the conclusions they draw.