During the first weekend of August, my son (along with my husband) completed the U.S. National Whitewater Center's Amphibious Duathalon.
The race was a 5K run/2K kayak paddle/5K run. (After finishing several races at the Whitewater Center over the past year, we can confidently say that their courses are always much longer than stated as well as being some of the most challenging trails we've even been on!)
Our son claimed the most difficult part of the race was trying to run uphill again after sitting in a kayak for 20+ minutes. Even so, he wound up finishing 14th overall, and 4th in his age group (which was 30 and under!). His father had a respectable finish also.