The idea of this test is to find out your max heart rate
It is not easy so be warned !!
Plenty of rest before. At least 48hrs from last training session

Warm up for 10-15 mins at 60-65% Max HR
Increase you HR by 5 beats every 2 minutes until you can no longer push your HR any higher !!
TIP You should be sprinting at the end
Warm down for 10 mins at 60-65% max hr
Write down your Max HR for further reference

If this is your first test you the following formula max rate = 220--age
Also,if you are a beginner cut the interval down to 1 min instead of 2