DBVR10H 10-Hour Lap Count Challenge

DBVR10H 10-Hour Lap Count Challenge

Discovery Bay Valley Road 10 hour laps challenge with 5K and 180m ascent per lap


8 min read

The challenge

Format: Limited time distance challenge.


  • Start from CP0. One lap is from CP0 to CP1 and back to CP0. Choose any path one prefers between the CPs.
  • One lap is about 4.8KM long and 175m ascent. Distance slightly varies by the exact path one follows.
  • Time limit: 10 hours. (commonly 8am-6pm).
  • Only count integral number of laps.
  • Self support.
  • Self track. Submit result here.

Course summary:

  • CP0: Discovery Bay Pier. 22.296710, 114.017372 (flower bed in front of Pacific Coffee). Google Maps pin
  • CP1: Discovery Bay Valley Road, Reservoir north east corner, 22.291570, 114.004900 (intersection with trail to Lo Fu Tau). Google Maps pin.
  • Shortest path is 2.1K single-way via Woodland stairs. Reference Strava activity.
  • A longer alternative is all along Discovery Bay Valley Road, 2.4K single-way. Reference Strava activity.
  • Elevation gain is about 160m-180m for one lap. (on average 175m measured by a sports watch).

Course details

Below is the reference map from my 1st attempt of this challenge: (60KM, 2325m)

DBVR10 Annotation.png


  • P1: CP0, aka the pier
  • P2: CP1, aka the reservoir
  • P1-P3-P7-P6-P2: The regular climb, 2.4KM, 175m climb. It is entirely concrete / vehicle road, highly runnable, little automobile traffic. You would see many other runners/ cyclers on the way. This is recommended route for both upward and downward direction.
  • P1-P3-P4-P5-P6-P2: Same climb but shorter distance (2.2KM), which means the slope is sharper. One can technically go faster on this route, but be aware that the used muscle groups are more diversified.
    • P3-P4: Steep stairs. This path is for resident's regular commute so the step size is minimal. Easy to power hike with only hip/ thigh.
    • P4-P5: Muddy climbs with medium slope. It is not efficient to run on this segment. Due to the variety of surfaces, many different muscle groups will be used. The segment is only 200m.
    • P5-P6: Very nice trail with small slope. Highly runnable with all hamstring (if you have the right pose).
    • Overall recoomendation: This path is good for upward direction to save some time; but less cost effective for downward direction.
  • P7-P2: One can climb the dam in straightline between the two points. This shortcut saves about 1KM and thus much time, if one want to seriously attempt the number of laps possible. Do not recommend for first trials/ exercising racers.

CP0: Discovery Bay Pier. 22.296710, 114.017372 . Google Maps pin. Touch the flower bed in front of Pacific Coffee.


CP1: Discovery Bay Valley Road, Reservoir north east corner, 22.291570, 114.004900 (intersection with trail to Lo Fu Tau). Google Maps pin. Touch this pole (1st one after red notice board).


Commute to Discovery Bay

Easiest way is to take ferry from Central Pier No.3 (DB). The ferry is usually scheduled every 30min and it takes 30min between Central Pier and Discovery Bay pier.

Alternatively, one can take land route:

  • MTR to Sunny Bay and then bus DB03R to DB's south plaza. (DB Plaza).
  • MTR to Tung Chung and then bus DB01R to DB's south plaza. (DB Plaza ).

Performance reference

Here are some references so you know what to expect:

  • Course record: 13 Laps on 2023-06-11, 29-39C, avg 32C. strava link.
  • HK100 champion (10 hours) shall be able to finish 22 laps on a good weather day.
  • HK100 16 hour finisher shall be able to finish 15.3-15.8 laps by cardio capacity alone. Considering this course is highly runnable, one shall expect to easily finish 16 laps with some residual spare time (you usually don't use up 10 hours as we only count integral laps), and do not feel any major muscle damage afterwards.
  • Similar HK100 reference points are: (take ceilling of laps)
    • HK100=15 hours; DBVR10H=17 laps
    • HK100=16 hours; DBVR10H=16 laps
    • HK100=17 hours; DBVR10H=15 laps
    • HK100=18 hours; DBVR10H=14 laps
    • HK100=19 hours; DBVR10H=14 laps
    • HK100=20 hours; DBVR10H=13 laps
    • HK100=21 hours; DBVR10H=12 laps
    • HK100=22 hours; DBVR10H=12 laps
    • HK100=23 hours; DBVR10H=11 laps
    • HK100=24 hours; DBVR10H=11 laps
  • The DBVR10H challenge is good for summer time. Given the study in Quantify temperature impact on speed, when the average temperature is 30C, one may lose 23% performance compared with when the average temperature is 20C. Note that one may experience a cliff of performance drop when temperature is (even temporarily) above 34.

Checkout all the results & notes contributed by the community here.


Why do we have this boring challenge?

  • Most of the races are distance bound time test. Only a few are time bound distance test. According to DUV records, 80% are time test and 8% are distance test (remaining unknown, maybe neither, e.g. last man standing).
  • Most distance test happens over (nearly) flat courses. However, majority ultra / trail running has an overall ascent / distance of 5%, e.g. 100KM distance with 5000m elevation gain.
  • The slope profile largely affects the muscle groups one recruit to move. It is hard to single out one's bottleneck being muscle strength or cardio capacity over long distance when slopes can be too sharp (>20%).
  • Surface/ terrain largely affects one's effective speed when the power output is the same. It is hard to single out one's bottleneck being running techniques (especially down hill) or cardio capacity.
  • Self-support is a challenge in the wild.
  • Weather in summer time is too dynamic. It is dangeous and hard to find immediate exit when caught in thunderstorm/ heavy rain.
  • I personally like to end the business before sunset and enjoy a beer. The more ideal setup to test cardio is to span the race from 6:00 to 18:00. Considering not everyone gets up so early, and also considering we'd like to eventually extend the invitation to runners outside Discovery Bay, a 10 hours window from 8:00 to 18:00 feels like a reasonable setup.
  • Only count integral laps: we want to measure how our training turned out over time, instead of pushing unnecessary limits for a single run. When it is in the latter part of the challenge, we encourage people to be rationale.

In short: we are building an ultra safe long distance challenge over road with 4%-5% ascent rate that has supplies (beer included) every 5KM for one to measure cardio capacity.


Mission & Vision

Mission: Organize endurance training for ultra runners at all levels in all seasons, and motivate conversations to co-build communities.

Vision: Establish 10H Series as a unique brand in Hong Kong's ultra running scene.

Runner's experience

Michael Gay on DBVR10H

Michael Gay, a 200mile ultra runner, commented below (Also find the TRAHK interview for his experience of Triple Crown in case you are interested).

I really enjoyed the Valley Road Challenge. My goal was to do 10 loops and wasn’t sure going in how long it would take or the best routes to take or how my body would respond. I enjoyed the concept of the race since there was many strategies you could take and alter throughout the challenge and did not need to carry much since every loop you were back in the DB plaza and could easily get food and drinks. Also my attempt was on a hot day which made going up a bit more challenging since running wasn’t really possible for 10 loops and the stairs and trail section seemed to be harder to do than the road although it may have been faster. I ended up taking the road 6 times and steps and trial 4 times up and then run the road all 10 times coming down. After the first couple loops I set a target of staying under a 40 minute a loop pace and was able to do that for my 10 loops but it wasn’t easy with the heat. The other cool thing of this challenge you are constantly seeing the other people taking on the challenge on most loops which was nice and always lifted your spirit. I believe in the heat all I could do over 10 hours would be 15 loops but I believe in the winter that 16 or even 17 loops would be achievable for my level. I feel the workout is also very good since there is very little flat so good for legs to go strong on ups and downs. I always enjoy these interesting challenges and this one was a lot of fun and something I will definitely attempt again.

Pili Hu on QB10H

Pili Hu , joined the Oct 1, 2023 session of 10H challenge at Quarry Bay, hosted by Terry and Lemon. Here's his experience of the event:

The course is well shaded. The supply choice is diversified ranging from 711 to local convenience stores. The Quarry Bay Sports Centre is well equiped with shower and locker. Overall experience is superior. Only point to improve is the granularity of the course, i.e. 10KM and 500m, which makes it difficult to push limits beyond 7 laps.


Race format distribution

We get data from DUV Statistics website, which collects races from the 1970s (some even date back to before 1900). The database is not complete but a reasonable sample of the Ultra world.

Here is the distance test (DT) v.s. time test (TT) distribution of the world:


Here is the DT v.s. TT distribution in Hong Kong:


  • Time Test (TT): fix the race distance (course) and test finish time. Examples are like HK100, Translantau, etc.
  • Distance Test (DT): fix the race duration and test the distance (e.g. lap count). One example is 24-Hour track challenge.

The above figure shows the distribution of TT v.s. DT in the world. The below figure shows the distribution of Hong Kong.

Apparently, HK is lacking DT to make a more comprehensive ultra landscape.

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