Download the test audio, get some cones, and practice. Just make sure you download the right test
What's your target - if you are talking the intermittent recovery test - is it a tough but softer 16.1 or something much harder like 17.4?
Whichever way, a lot of it is psychological. The first time you get to 15.6 (or 16.6) you feel like the world is ending and you give up. The next time you realise you can do more.
Some people will tell you can't practice technique for this but I disagree. I see a lot of incredibly fit guys, running through the 17s, 18s, into the 19s and they could go so much further... but they just don't use their arms. When it gets tough use your arms to accelerate after turns. And it helped me to settle on a stride pattern so I always knew when it got tough that I was going to turn on the same foot.