It started as a little challenge to myself to see if I can make it back to Namche in under 6hrs.
I was carrying a big backpack with sleeping bag and stuff for an adventure as I had crossed a non tracked pass the other day. Therefore, this FKT can be easily challenged in proper running gear! Probably can be done in under 4hrs.
Initially I wanted to have a go at the Lukla - EBC uphill FKT but I got the horrendous Khumbu cough and was impossible for me to push myself.
But this smaller downhill FKT is still a nice achievement. The route is brilliant and totally runnable (by Himalayan standards) getting you from the glacier lakes at 4800m in Gokyo down to the forests and the Sherpa village of Namche Bazaar at 3400m.
There is still some uphill to be done especially the gruelling 400m D+ from Portse Tenga to Mong La (3600m to 4000m) which I managed in 38min coughing my way up.
I recommend to attempt it properly acclimated.
For me it was a nice little challenge and happy to make it in under 5hrs under the given conditions.