Check out the following article about World 1500m bronze medallist Shannon Rowbury:-

http://www.spikesmag.com/features/irishdancingisthesecretbehindmytracksuccess.aspx

“When I was in kindergarten I tripped over a basketball and fractured my tibia. My grandmother, who is Irish, said I should do Irish dancing to help strengthen my leg. I feel that was really huge in developing me as an athlete. It helped me with my fast-twitch development and hip strength. "

I'm delighted to see such a statement from a World medalist as I've often wondered about this connection. We have several athletes in the club who were very good Irish dancers and who are also exceptionally good athletes. There's definitely something in that theory that it develops the fast-twitch muscles.

For anyone reading this not familar with their 'twitches', your fast-twitch muscle fibres are the parts of your muscle responsible for exerting tremendous power, sich as jumping, while the slow-twitch fibres are more involved in endurance activites where they exert less power but last much longer. A good example of the difference is a chicken – lots of slow-twitch fibres in their legs so they can walk around all day, and lots of fast-twitch fibres in their wings so they can very briefly produce so much force that they get up into the air for 10 seconds.