I used to be in fantastic shape. I could do the Grouse Grind in roughly 45 minutes, I would be able to run for miles without needing to pause for breath, I actually had a pretty well defined body, etc. I think you get the point. I didn't do a lot of working out at the gym; I'd merely do martial arts for two hours every day, half of which was cardio/working out stuff. However, my career at the time forced me away from martial arts and away from pretty much any form of exercising. As a result, I lost pretty much everything I had worked up over the years. I do physical labour so my upper body strength is pretty decent, but my cardio has gone to shit. I played soft ball yesterday at a company function and... fuck, that was a wake up call. I had trouble simply running around all the bases!

Now, I smoked for a few years and recently quit, but I don't have asthma. I'm simply that out of shape.
I've set myself a goal for finishing the Grouse Grind in under 1.5 hours before the end of summer, but I'm having trouble trying to get myself back into a semi-decent cardio shape before tackling it. What sort of activities or exercises do you guys recommend to get me started? I tried a relatively semi-intensive workout the other day and felt like throwing up after about ten minutes
Any help would be appreciated.