Has any body on here got much experience of these?
For the past couple of years have been setting myself some challenges to keep in shape. 2011 I did my first 12 hour endurance race as a pair, last year I ran a marathon buy this year I have let it slip. Was looking for something to give me a kick into the new year as thought this could be it!
Not done one before but like the idea. Are they really hard work? Do I need to do a lot of rspecific training or is general bike and run fitness ok?