Uphill training tips

[bena]

I'm reeeeally slow going uphill. What are the best tips for improvement?

My sense is that it is my cardio / aerobic fitness that is the weak link - not my legs. This based on the fact that on a 8.2k uphill/ downhill course my legs aren't hurting and still have plenty left in them for the downhill, but my heart rate was averaging about 94% of max on the climb and I am gasping for air.

In a field of about 100 runners, I was about 40th at the top and apparently really struggling compared to those around me. I made up around 15 places on the down, and would have gone faster if it wasn't for being held up on stretches of single track.

If my HR is right up there, am I blessed with a crap aerobic system, or is my training lacking something and can I improve my fitness? Are there things in my technique that could be making me work harder?

Thanks in advance...