Help....having had a week of running to my own music gaily I decided to do the first stepping stone today. It was a shocker no doubts! First the walk warm up bit was about twice as fast as I was expecting then the 150bpm was supposed to be resting speed but nearly finished me off. For the first time ever I gave up after 10 mins....just don't have anywhere near that level of fitness yet. So what do I do now - I need to get my speed up but slowly not immediately doubling like this....anybody got any tips please?