After a short warm-up of 2 km flat, you go through 6 loops, each consisting of a short downhill, a steep uphill, and a flat part. At the end you have 3 kms to cool-down. Very nice video for interval training. Try it out: go full power on the uphill, try to maintain rather high power during the flat part, and relax on the downhill so that you start the next uphill with low HR (60% of your max).
See my other videos and playlists at https://dashboard.kinomap.com/en/users/129864/playlists