Sam loves agility. I have not shown her in a couple of years, but according to AKC year end finals printed in June 2000, she was tied for #1 in the country in Newfoundland Novice A Standard Agility. Just had to brag.
Now Sam is 27" and weighs about 112 lbs. I plan to start her again this year. I kinda frowned on AKC because she had to jump 24" but now they have a new class where she can jump 20". I was worried about the stress on her front end jumping that high, so that is why we stopped. At the age of 4 she is considered a vetern in CPE which allows a lower jump height. UKC allows newfs jump one height lower due to their bulk.
Conditioning is very important. Swimming is the best exercise to build up those muscles. In practice don't jump your newf at the full height all the time. Remember to make the training exercises fun. Most can be done a lower heights and they can learn as much, such as footwork, judging distance to jump, go outs, spot and pacing themselves. The most important thing for you to remember is. Your newf is much bigger than all those other agility dogs so you will need to allow time for extra wide turns and set up for a longer stride to the jumps or contact obstacle.
It is fun, just enjoy!!!