Interval Variable. 10k Fartlek An old favorite. The distance is split into 9 unbroken sets (1k). Set 1 is 900m paddle (40%) - 100m at 80%. Set 2 is 800m paddle - 200m at 80%. Set 3 is 700m paddle - 300m at 80%. And continue until you have 100m paddle and 900m at 80%. The last 1k is cool down/recovery. ⚠️Caution: don’t force the recovery/paddle at 40% as this develops you may find yourself at the back end going slower, it's fine. It’s a tough one. If you need to chose a lower intensity between 70%-80% that’s fine too. It’s important mentally that you finish it.