OpenLakes 70.3, Lac de l'Eau d'Heure Belgium, 19 Sep 2026

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Preparation

In preparation of this race I finally went and had my sweat rate analyzed, that showed that I loose up to 2 liters of sweat per hour which in my case corresponds to 2.8g of sodium per hour, recommended to replace around 0,8-1,4g Sodium per hour. So I tried to adjust my water and sodium intake on the bike to compensate for this during the race. 

No injuries worth mentioning leading into this race.

Last year I finished in 4:57:11 here, so I was hoping to do better or at least to go under 5 hours again.

Location



Start, T1/T2 and finish line are all located at "Les Lacs de l'Eau d'Heure" a lake close to Cerfontaine, south of Charleroi in Belgium. 

Stay

As the race venue isn't to far away and there was no need to leave the bike the day before the race, I didn't opt to stay close to the venue and just made the trip on race morning. 

Swim 0:32:21 (AG-6/123)

  • One loop mass beach start swim, as always I started on the right hand side of the pack. Pretty clean water from the get go for me, started of relaxed and got into a good rhythm early on. Even the battle around turning buoy 1 wasn't bad at all. Between turning buoy 1 and 2 I found some good feet to sit on which I followed all the way past turning buoy 3. At turning buoy 3 I actually got caught up in the ropes that kept it in place so had to put a dig in to get back onto this athletes feet. Somewhere on the long straight after turning buoy 3 that athlete seemed to stop swimming so for a while I just kept my own pace until at some point some other athlete swam passed me and I jumped onto his/her feet. The last stretch until the swim exit I didn't find any feet to sit on, most likely because I was apparently swimming of course which I noticed pretty late.
  • AG 5% and similar time and pace compared to last year:
    • 2025: 0:32:38 - 1:43/100m
    • 2024: 0:32:32 - 1:42/100m
    • 2023: 0:29:47 - 1:34/100m

T1 0:03:43 (AG-10/123)

  • Had a hard time opening up the Velcro of my wetsuit running into T1, but doubt it has cost me more than a few seconds.
  • Same remark as past years: I really don't understand why they don't add more carpet in their transition zone, every time a painful transition zone due to the rough tarmac!
  • AG 8%

Bike 2:45:39 (AG-8/123)

  • 2 laps of 46k each, very rolling terrain, barely any flat, exact same course as last few years so I was familiar with it.  
  • In the beginning of the bike leg I struggled to get my power numbers up to the 250W range where I wanted it to be. After taking in some carbs I started to feel much better. During the second real climb my chain dropped when trying to switch to the smaller front chain ring, got it back on relatively quick though, but it was a good reminder to be extra careful with my gearing. The wind was brutal, adding to the already hard course. Having the Cave triathlon scenario in my head I tried to keep my power numbers around 250W and not above 280-300W on the climbs, I thought I managed to do that relatively good but my NP says 238W which I can't get my head around, I thought it would have been in the 250-260W range. Even with keeping the power numbers in check I still felt my legs were pretty beaten up near the end of the course. In the latter part of the course I tried to get my breathing under control, take some deep breaths and sit up from time to time to avoid having stitch issues during the run.

  • Nutrition wise I swapped my 750ml bottles to 950ml bottles to be able to increase my water intake. Basically per 30k I tried to drink 1l and empty 1/3rd of my carb bottle, sometimes it was hard to find a safe spot to drink with all the wind but managed it as good as I could and emptied everything:
    • 2x950ml: 3 scoops (45g carbs) + 1 hydro tab (840mg Sodium) = 90g carbs + 1680mg Sodium
    • front hydration: somewhere above 1l: - 3 scoops (45g carbs) + 1 hydro tab (840mg Sodium)
    • carb bottle: 750ml: 3 gels (50g carbs) + 1 ORS solution = 150g carbs + 350mg Sodium
    • Which results in a total of around: 3,6l + 285g carbs + 2870mg Sodium. 
    • So in terms of intake per hour that results in about: 1,3l, 103g carbs and 1,040 mg Sodium which is where we wanted it to be.
    • Twice I took a bottle at an aid station and drank a good amount before dropping it in the same aid station, but I think it was mostly water. Additionally I took about 4 salt caps as well as my calves were feeling like cramping during the first half of the course and my hands and triceps were cramping as well, but not sure how much anymore so didn't count those.
    • In the second loop I started to burp so need to train my stomach more or need to dial the intake a little down. Especially because normally a 90k course doesn't take 2:45', so on a faster course I would need to dial down the intake a bit, maybe focus on intake per hour and not per 30k. 
  • AG 7% - 238W NP, 33.3 km/h avg, still no idea how it's possible my NP was so low with all the inclines and the wind, but AG % wise actually not bad at all. Looking back at previous years it was actually almost spot on compared to 2024:
    • 2025: 2:39:29, 253W NP, 24.4 km/h avg
    • 2024: 2:45:26, 226W NP, 33.3 km/h avg
    • 2023: 2:32:46, 251W NP, 36.0 km/h avg  

T2 0:02:25 (AG-5/123)

  • Last k coming into T2 I took it a bit easier and kept my breathing under control. Jumping of the bike the legs felt good and no cramping at all. T2 took a bit longer than usual as I was using a running vest this time to be able to take some extra water onboard. 
  • AG 4%

Run 1:52:14 (AG-62/123)

  • 3 laps of 7k, very rolling the first half of the lap. After such a hard bike leg this one always hurts in the quads. 
  • I actually felt relatively good running out of T1, the quads were hurting and close to cramping up during the inclines, but that was as expected. I didn't look at my watch for pace but just ran a pace that felt comfortable which went ok until the end of the first lap when I started to feel pretty bad. I had such a dip that I really thought about pulling out, but as my parents took the effort to make the long drive to cheer for me I couldn't just give up, so I took a pee break and started jogging again. From there onwards I tried to keep on running in between the aid stations, walk at the incline at the far side of the course and take my time during every aid station to get some cola in. At the end of the second lap I took a longer toilet break, which I normally never need to do, no idea how that happened. And the last lap was just about getting home with the idea that everyone I could pass meant a position better in the final ranking. 
  • Only positive I can think of is that running with the running vest went ok, enough storing capacity for 1l, a few gels and salt caps. 
  • Side note: their idea to go cupless was just ridiculous, instead of having cups ready to go at the aid stations, they gave us a refillable cup while heading out of T2 and at every aid station there were volunteers who tried to fill your cup from a big jar or bottle and water fountains to fill your cup, just a clusterf** if you ask me.
  • AG 50% - 5:39/km is in one word just horrible.
    • 2025: 1:38:01 - 4:54/km
    • 2024: DNF
    • 2023: 2:11:20 - 6:13/km

Overall 5:16:24 (AG-15/123)

  • Hard to find any positives in this race, except for the swim which went as normal and that I finished I don't see any positives. Power numbers apparently were way lower than what I was assuming they were on the bike and the run was just shameful, not what I except from putting so much time into training.
  • AG 12%, percentage wise actually not even that bad, but the overall feeling is very negative.
    • 2025: 4:57:11 AG-73/469
    • 2024: DNF
    • 2023: 5:20:23 AG-108/299

Some lessons learned

  • Need to try some things out in my nutrition, not sure what makes me feel that bloated, the gels, the sport mix or the hydro tabs, or just the fact of drinking voer 3 liters over 90k? 
  • Running with a running vest did work to get extra liquids in, never during the run I had the feeling of very heavy legs.

Result

  • Run     0:32:21 (AG-6/123)
  • T1       0:03:43 (AG-10/123)
  • Bike    2:45:39 (AG-8/123)
  • T2       0:02:25 (AG-5/123)
  • Run    1:52:14 (AG-62/123)
  • Total   5:16:24 (AG-15/123)



Tags: OpenLakes 70.3 race report, race report OpenLakes 70.3

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