Track work equals hard work

You hear about people doing track work to improve their speed, you read about speed training in running magazines, but really...I didn't think  was for me. I've never tried it before, only heard other, better runners talk about it.  Well, this morning it was my turn.  My running man decided it was time for me to step up my training somewhat and introduce some speed training.  The plan: to run much faster than what you're used to for 800m ie twice around the track and then cool down and catch your breathe for 400m ie once around the track.  Repeat five times with no stopping, no walking, no collapsing.  Trust me, it sounds easier than it is! So of course, this being my first time at really sprinting around a track, my pacing was rubbish.  Like a real coach, my running man sat at the start with a stop watch and after my first 400m he shouted "too fast" as I ran past.  Well, about 3seconds later I knew what he meant! I couldn't keep up the pace and completed my second 400m too slowly!  On the cool down my coach jogged with me and gave me some pointers.  I couldn't say much in response as I was too busy dying from loss of breathe.  However, apparently this is normal...the point is to push yourself faster than what you're normally capable of. So when we finished the first cool down, he decided that perhaps I needed him to be my pacer to help me get my timing right.  Again, the first 400m I stayed close behind him but in the second lap, I fell pretty far behind and just couldn't keep up.   He kept turning around and shouting "stay with me" and if I could talk at all, I would have said "I'm trying dammit!"  Another little pep talk on the cool down resulted in repeat number 3 being spot on (of course there were more shouts of "don't slow down" and "run faster!").  I managed to keep up the pace and finished the 800m in the goal time! Same for the last two repeats.  After the 6km of speed training, I couldn't speak, it felt like my stomach was in my throat and my heart was about to explode.  But again, apparently this is normal!??  They say this kind of ridiculous training is supposed to help your speed...well it better, because I'm going to be pretty upset if I keep putting myself through this for nothing!