Summary

The key objective for this race is to test if I can manage a 70K without Pocari water, which I always depended on since the first trail run. I have decoupled from energy gels/ energy bar/ poles, but have not tried to decouple Pocari and use salt stick only.

Given that key variable and foreseeable slippery surface/ rain patches, I made a plan of 12 hours in Playbook of Salomon Lantau 70, just enough to catch the 8:30pm ferry. I have good enough buffer in terms of cardio, in order to better work with other unknown situations.

Notes

Race Log:

• Mode: no poles, no energy gel, no energy bar. No Pocari water, only salt stick.
• Parametes: smooth-dist = 100m, D/A = 1K/100m, pace decay = 8%.
• Pre-race plan was to start with 6:00, overall 12 hours, so I catch 8:30pm ferry back home.
• Race start delayed for 10min. Adjusted equivalent pace to 5:50 to catch the 8:30pm ferry.
• Every point was right on target till CP2 Tai O, variance < 2 min.
• Race paused at 1pm and resumed at 1:40pm due to thunderstorm warning.
• I reached Tai O at 1:22pm, right on target. Since I had planned 20min for lunch, the race pause did not impact my time table.
• Almost thought of quit, as all wet, water in shoes, some blisters on foot.
• Weather became good after the storm.
• Due to unplanned rest for many runners, the pack from Tai O to Shek Pik was fresh. I naturally oversped for about 10min following some of them.
• Adjusted timetable at Fen Shui Au: change actual arrival time, keep equivalent pace to 5:50.
• Chopped about 5min on catch water to Shek Pik, as I saw the lead female runner and tempted to keep up her pace. HR=140, a bit over than my plan, but within buffer zone.
• The fried rice at Shui Hau CP was untouched when I arrived. I became the first one to sit down and had three bowls. More runners followed, sat, ate and had conversations.
• Chopped about 20min off previous plan on the catch water from Shui Hau to Pui O. I was all alone. Not racing anything. Kept HR=130-140.
• Did not stop at Pui O CP. Grabbed 500mL water and continued.
• Adjusted timetable at Pui O: change actual arrival / departure time, keep equivalent pace to 5:50.
• About 5-6 runners passed me on last leg. I did not race and kept the pace. The segment time is -2min (out of 1 hr 10min).
• Was in a pack of around 10ppl. I passed everyone on uphill and then everyone passed me on downhill. The pattern continued for around 40K, until downhill to Shui Hau, which is too technical. Afterwards, only moderate climbs to the finish line. The pack was gone for good, never back to my sight.

Post race condition check:

• 2nd day performance: pace/ HR almost no impact, would rate cardio status 0.95; has muscle soreness, especially hamstring, would rate as 0.8 overall.
• Hamstring soreness is expected, as Shui Hau catch water over speed (from 7:09 planned pace to 5:30~6:00 actual pace). Better exercise loading compared to plan.
• No quad issues at all, meaning I could go faster on downhill (as many others at similar overall time went much faster than me).
• A bit full body soreness, unexpected, mainly due to overspeed (and over HR) at Fan Lau - Shek Pik catch water.
• Water calculation was very precise. Slight dehydration post race, due to ~300-400ml consumed compared with plan, on Shui Hau - Pui O catch water.
• 100mg~150mg sodium per 500mL seems to be enough, when there are dietary sodium intake from natural food (fried rice, potato chips, nuts). (Reference: Pocari is about 250mg Sodium per 500mL).

Time reconcile:

• Pre race elapsed time by plan: 12:00
• Race start elapsed time by plan: 11:40
• Final elapsed time by plan: 11:15
• Final moving time is 10:30
• Break time: CP2 - 20min; CP1 / 3/ 4 - each 5min. (skipped Pui O)
• Net 35min overspeed after Tai O.
• Major overspeed breakdown: (rough)
  • Tai O to Fan Shui O - 10min
  • Fan Lau to Shek Pik catchwater - 5min
  • Shui Hau to Pui O catchwater - 20min
  • Pui O rest removal - 5min

Others:

• Tripped over on the climb from Tai O to Tai Ngau Wu, almost at the top. It was misty and the headlight has reflections in front of eyes. Tripped at the tip of the stair. Luckily was not moving fast. Naturally fell supported by hand and rolled to side. No wounds or scratches. Left hand wrist had pain but functional.
• The first time I saw most runners before me at half way points. I saw race leaders at Fen Shui Au when they came up from Tai O and I went down to Tai O. Thanks to the course design! I saw 20-30 runners crowded at Tai O waiting for thunderstorm signals to go away. If not for ther weather, I would not see ~10 of them for sure. Another ~10 were in the same dynamic pack with me and I knew I would not see them after Tai O, because my lunch time is really long.

If I could choose again:

• I would remove the "race" part of Fa Lau to Shek Pik catch water. I had good margin and had adquate reserve for the later flat segments. There was no point to catch up a few minutes at the cost of introducing more lactate.
• I would put extra shoes/ socks/ clothes at Tai O, and resume the race with dry suits in comfort.
• I would prepare a handheld torch, in complement to the headlight. In misty environments, the reflection from nearby vapour can make blur the sight.

Data

Compare the actual gpx file with plan:

Note that the above is not accurate since the cummulative distance of CP3/ 4/ 5 from the website is off (from a few hundred meters to 2KM). See detailed notes for the actual time gain / loss. HR efficiency by 5KM segments:

This shows that my efficiency stayed at the same level through out the race. The performance drift is within 5%. Only low efficiency segment is 25-30K, due to rest at Tai O (Need to calibrate the algorithm with more accurate rest HR).

Pace drift:

I have oversped along two catch waters, for 21% and 17%, respectively. The first one is which I regret doing so (a bit over) and the second one is the natural "feeling good" part.

For most other segments, the pace drift is within 10% difference to the plan. The only unconsious drift over 10% is Ngong Ping to Keung Shan, for two reasons: 1) initial 2K moderate slope down hill is a natural accelerator without sacrificing HR efficiency; 2) I was naturally better on uphill than downhill.